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GNU Image Manipulation Program 1 / 653

GNU Image Manipulation Program

User Manual

Summary of content (653 pages)

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GNU Image Manipulation Program 1 / 653 GNU Image Manipulation Program User Manual
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GNU Image Manipulation Program 2 / 653 Copyright © 2002, 2003, 2004, 2005, 2006, 2007 The GIMP Documentation Team Legal Notice Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section enphrased GNU Free Documentation License.
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GNU Image Manipulation Program 3 / 653 COLLABORATORS TITLE : REFERENCE : GNU Image Manipulation Program ACTION NAME WRITTEN BY DATE SIGNATURE July 26, 2007 REVISION HISTORY NUMBER DATE $Revision: 1985 $ 2007-07-15 DESCRIPTION NAME romanofski
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GNU Image Manipulation Program 4 / 653 Contents I Getting started 21 1 Introduction 22 1.1 1.2 2 1.1.1 Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 1.1.2 The GIMP-Help system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 1.1.3 Features and Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 What’s New in GIMP? . . . . . . . . . . . .
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GNU Image Manipulation Program 5 / 653 3.3 Undoing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 3.3.1 3.4 3.5 4 5 6 GIMPLite Quickies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 3.4.1 Intention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 3.4.2 Change the Size of an Image (Scale) . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 6 / 653 7 Painting with GIMP 7.1 7.2 7.3 The Selection 75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 7.1.1 Feathering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 7.1.2 Making a Selection Partially Transparent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Creating and Using Selections . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 7 / 653 9 Enhancing Photographs 9.1 122 Working with Digital Camera Photos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 9.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 9.1.2 Improving Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 9.1.3 Improving Colors . . . . . . . . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 8 / 653 III Function Reference 157 12 Toolbox 158 12.1 The Toolbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 12.1.1 Tool Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 12.2 Selection Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 12.2.1 Common Features . . . . . . . . . . . .
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GNU Image Manipulation Program 9 / 653 12.5.3 Colorize Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 12.5.4 Brightness-Contrast tool 12.5.5 Threshold Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 12.5.6 Levels tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 10 / 653 13.5 Misc dialogs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 13.5.1 Tools Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 13.5.2 Preferences Dialog 13.5.3 Device Status Dialog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 11 / 653 14.5.9 Save a Copy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 14.5.10 Save as Template . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 14.5.11 Revert . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 14.5.12 Print . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 12 / 653 14.7.15 Toggle QuickMask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 14.7.16 Save to Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 14.7.17 To Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 14.8 The ‘View’ Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 13 / 653 14.9.15 Print Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 14.9.16 Scale Image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 14.9.17 Crop Image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 14.9.18 Autocrop Image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 14 / 653 14.10.26Stretch Contrast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 14.10.27Stretch HSV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388 14.10.28Autocrop Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389 14.10.29The ‘Mask’ Submenu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 15 / 653 15 Filters 15.1 Introduction 411 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411 15.1.1 Preview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412 15.2 Blur Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412 15.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 16 / 653 15.4.5 Scatter HSV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455 15.4.6 Slur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456 15.4.7 Spread . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457 15.5 Edge-Detect Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 17 / 653 15.10.5 IWarp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500 15.10.6 Mosaic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502 15.10.7 Page Curl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503 15.10.8 Polar Coords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 18 / 653 15.13.3 Solid Noise 15.13.4 Flame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 561 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 563 15.13.5 IFS Compose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 565 15.13.6 Diffraction Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 19 / 653 A GIMP History 628 A.1 The Very Beginning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 628 A.2 The Early Days of GIMP A.3 The One to Change the World . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 629 A.4 New in GIMP 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 628 . . . . . . . . . . . . . . . . . . . . . . . . . .
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GNU Image Manipulation Program 20 / 653 Preface User Manual Authors and Contributors Content Writers William Skaggs, Ćedric Gémy, Julien Hardelin, Raymond Ostertag, Mel Boyce, Daniel Egger, Róman Joost, Oliver Ellis Graphics, Stylesheets Jakub Steiner, Róman Joost, Daniel Egger Build System, Technical Contributions Sven Neumann, Michael Natterer, Henrik Brix Andersen, Daniel Egger, Thomas Schraitle, Chris Hübsch, Axel Wernicke Project Maintenance Róman Joost, Daniel Egger
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GNU Image Manipulation Program 21 / 653 Part I Getting started
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GNU Image Manipulation Program 22 / 653 Chapter 1 Introduction 1.1 Welcome to the GIMP The GIMP is a multiplatform photo manipulation tool. GIMP is an acronym for GNU Image Manipulation Program. The GIMP is suitable for a variety of image manipulation tasks, including photo retouching, image composition, and image construction. It has many capabilities.
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GNU Image Manipulation Program 23 / 653 • Sub-pixel sampling for all paint tools for high-quality anti-aliasing • Full Alpha channel support for working with transparency • Layers and channels • A procedural database for calling internal GIMP functions from external programs, such as Script-Fu • Advanced scripting capabilities • Multiple undo/redo (limited only by disk space) • Transformation tools including rotate, scale, shear and flip • File formats supported include GIF, JPEG, PNG, XPM, TIFF, TGA, MPEG
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GNU Image Manipulation Program 24 / 653 1.2.3 Plug-in Previews We have provided a standard preview widget for plug-in authors which greatly reduces the amount of code required to support previews. David Odin has integrated this widget into all the current filters, so that now many more filters in the GIMP include a preview which updates in real time, and the various previews behave much more consistently. 1.2.
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GNU Image Manipulation Program 25 / 653 Chapter 2 Fire up the GIMP 2.1 Running GIMP Most often, you start GIMP either by clicking on an icon (if your system is set up to provide you with one), or by typing gimp on a command line. If you have multiple versions of the GIMP installed, you may need to type gimp-2.2 to get the latest version. You can, if you want, give a list of image files on the command line after the program name, and they will automatically be opened by GIMP as it starts.
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GNU Image Manipulation Program 26 / 653 set lang=fr cd c:\Program Files\GIMP-2.0\bin GIMP-2.2.exe Save this file as GIMP-FR.BAT (or another name, but always with a .BAT extension. Create shortcut and drag it to your desktop. Windows ME Start/Programs/ Accessories/System Tools/System Informations/Tools/System Configuration Utility/"Environment" tab/"New" button: Enter LANG for Name and fr or de... for Value. Windows 95/Windows 98 Under Window 95 and Windows 98, add the line set lang=en in the ‘C:\autoexec.
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GNU Image Manipulation Program 27 / 653 1. Since this window mentions the GNU General Public License you know it is truly a Welcome dialog you are entering into. Also, note the ‘Continue’ button. GIMP does not even ask that you agree to it, merely whether you want to continue. Feel free to press the continue button. Figure 2.1: Welcome The Welcome screen 2.
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GNU Image Manipulation Program 28 / 653 3. This window shows you the files that GIMP will create. It will have some complaints if you told it to install some place that it don’t have permission to be. There is a scroll bar to see all the things GIMP has created for you. Figure 2.3: User Installation Log The User Installation Log screen. 4. Setting your memory usage is not an easy thing. So much depends on what your needs are for the GIMP and what hardware you have to work with.
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GNU Image Manipulation Program 29 / 653 Figure 2.4: GIMP Performance Tuning The User Performance Tuning screen Finally . . . So now you have GIMP installed and configured, and are ready to go. Just a couple of suggestions before you start, though: First, when you run GIMP, by default it shows a "tip" each time it starts up. These tips tell you things that are very useful but not easy to learn by experimenting, so they are worth paying attention to.
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GNU Image Manipulation Program 30 / 653 Chapter 3 First Steps With Wilber 3.1 Basic Concepts This section is intended to give you a brief introduction to the basic concepts and terminology you will need to understand in order to make sense of the rest of the documentation. Everything here is explained in much greater depth elsewhere.
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GNU Image Manipulation Program 31 / 653 large number of tools for doing it: an assortment of selection-making tools, a menu of selection operations, and the ability to switch to Quick Mask mode, in which you can treat the selection channel as though it were a color channel, thereby ‘painting the selection’ Undoing When you make mistakes, you can undo them. Nearly everything you can do to an image is undoable.
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GNU Image Manipulation Program 32 / 653 3.2 Main Windows Figure 3.1: The screenshot illustrates the standard windows of GIMP The screenshot above shows the most basic arrangement of GIMP windows that can be used effectively. Three windows are shown: v 1 v 2 v 3 v 4 v 5 The Main Toolbox: This is the heart of the GIMP. It contains the highest level menu, plus a set of icon buttons that can be used to select tools, and more.
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GNU Image Manipulation Program 33 / 653 This is a minimal setup. There are over a dozen other types of dialogs used by GIMP for various purposes, but users typically create them when they are needed and close them when they are not. Knowledgeable users generally keep the Toolbox (with Tool Options) and Layers dialog around at all times. The Toolbox is essential to many GIMP operations; in fact, if you close it, GIMP will exit. (You are asked to confirm that you want to do this, though.
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GNU Image Manipulation Program 34 / 653 Tip In the Toolbox, as in most parts of GIMP, moving the mouse on top of something and letting it rest for a moment will usually bring up a "tooltip" message that may help you understand what the thing is or what you can do with it. Also, in many cases you can press the F1 key to get help about the thing that is underneath the mouse.
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GNU Image Manipulation Program 35 / 653 3.2.2 Image Window Figure 3.3: A screenshot of the image window illustrating the important components In GIMP, each image that you have open is displayed in its own separate window. (In some cases, multiple windows may all display the same image, but this is unusual.) We will begin with a brief description of the components that are present by default in an ordinary image window.
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GNU Image Manipulation Program 36 / 653 v 7 v 8 v 9 Units menu: (This feature is new in GIMP 2.2; it does not appear in GIMP 2.0). By default, the units used for the rulers and several other purposes are pixels. You can change to inches, cm, or several other possibilities using this menu. (If you do, note that the setting of ‘Dot for dot’ in the View menu affects how the display is scaled: see Dot for Dot for more information. Zoom button: (This feature is new in GIMP 2.
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GNU Image Manipulation Program 37 / 653 Figure 3.4: A dock, with docking bars highlighted Each dock has a set of docking bars, as highlighted in the adjoining figure. These are thin gray bars, very unobtrusive and easy not to notice: most people don’t realize that they exist until they are specifically pointed out. 3.2.3.2 Docking Drag Handles Each dockable dialog has a drag handle area, as highlighted in the figure on the right.
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GNU Image Manipulation Program 38 / 653 Menu that is the Menu of the active image on your screen). If the Auto button is depressed, then the menu always shows the name of GIMP’s currently active image, that is, the image you are currently working on. Figure 3.6: A dock with an Image Menu highlighted By default, a ‘Layers, Channels, and Paths’ dock shows an Image Menu at the top, and other types of docks do not.
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GNU Image Manipulation Program 39 / 653 Figure 3.8: Tab menu from the Layers dialog The Tab menu gives you access to the following commands: Context Menu At the top of each Tab menu is an entry that opens into the dialog’s context menu, which contains operations specific to that particular type of dialog. For example, the context menu for the Patterns dialog contains a set of operations for manipulating patterns.
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GNU Image Manipulation Program 40 / 653 Figure 3.10: Preview Size submenu of a Tab menu El submenú "Tamaño de la vista previa". Many, but not all, dialogs have Tab menus containing a Preview Size option, which opens into a submenu giving a list of sizes for the items in the dialog (cp. Figure 3.10 ). For example, the Brushes dialog shows pictures of all available brushes: the Preview Size determines how large the pictures are. The default is Medium. Tab Style Figure 3.
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GNU Image Manipulation Program 41 / 653 Undoing can itself be undone. After having undone an action, you can redo it by choosing Edit → Redo from the image menu, or use the keyboard shortcut, Ctrl-Y. It is often helpful to judge the effect of an action by repeatedly undoing and redoing it. This is usually very quick, and does not consume any extra resources or alter the undo history, so there is never any harm in it.
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GNU Image Manipulation Program 42 / 653 a closed path by clicking at multiple points in the image, and then clicking inside the path to create a selection. You cannot undo the individual clicks: undoing after you are finished takes you all the way back to the starting point. For another example, when you are working with the Text tool, you cannot undo individual letters, font changes, etc.: undoing after you are finished removes the newly created text layer.
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GNU Image Manipulation Program 43 / 653 Figure 3.13: GIMP Used for Image Scaling Image entry in the menu and the sub menu from the screenshot should reveal itself. Click on Scale Image.... When ever you click an option from the menu that has ... behind it, expect another dialog. This time, you should get the Scale Image Dialog. Figure 3.14: Dialog for Image Scaling in Pixels If you have a desired width, put it in the dialog at the top where it says New Width.
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GNU Image Manipulation Program 44 / 653 Figure 3.15: Dialog for Image Scaling in Inches Perhaps you want your image to look more like a 4x6 inch photo on most image rendering web browsers. Simply switch the units to ‘inches’ and put 4 inches in the height box (opting for smaller than 4x6 rather than bigger). You can see this dialog above. Let The GIMP choose the other dimension length for you. Meaning, it will take more image knowledge to change both width and height and have it look correct.
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GNU Image Manipulation Program 45 / 653 Figure 3.17: Dialog for Image Saving as JPEG If you would like to make it smaller still, make sure that the ‘Preview’ toggle is on and then watch the image area and change the compression level by moving the ‘Quality’ slider down. You can see the quality of the image changing, especially towards the leftmost end of the slider. Above is a screenshot of me doing this very thing. As you can see, very small is also very bad.
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GNU Image Manipulation Program 46 / 653 Figure 3.18: Dialog for Image Saving as JPEG I have not been showing the actual jpegs I created so that we could end this quickie with a race. Figure 3.19: Example for High JPEG Compression (a) Quality: 0.06; Size: 1361 Bytes (b) Quality: 0.42; Size: 3549 Bytes Figure 3.20: Example for Moderate JPEG Compression (a) Quality: 0.85 (GIMPs default); Size: 6837 Bytes (b) Quality: 1.
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GNU Image Manipulation Program 47 / 653 3.4.4 Crop An Image Figure 3.21: Example Image for Cropping (a) Source image (b) Image after cropping Many reasons to need to crop an image. Making rectangles square, or making squares into rectangles. Cutting alot of useless button on the toolbox background to bring out the subject better. etc. To get to the crop tool, you can either push the or right click on the image and follow the menu Tools → Transform Tools → Crop and Resize in the image window.
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GNU Image Manipulation Program 48 / 653 Figure 3.23: Dialog for Cropping After completeing the click and drag motion, a little ‘Crop and Resize Information Dialog’ (shown above also) pops up, telling you information about the borders that were defined in the click and drag. We will have to change all of the numbers. If you would like to make this rectangular image square, you should find the width and height from the Get Image Information Quickie (see Section 3.4.5.
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GNU Image Manipulation Program 49 / 653 Figure 3.25: Dialog for Image Info If you are just making a square out of a rectangle, like in the Section 3.4.4, you need only to open the dialog and find the lesser length and use that as described. Since this is very little information, and definately not enough to fill the space between the menu thumbnail and the dialog screenshot in my layout, I thought I would run through some calculator exercises that might help you to meet your image needs. Figure 3.
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GNU Image Manipulation Program 50 / 653 Figure 3.27: Problem Solved by Cropping There will be problems whenever mixing scanned photos with digital photos and also with scanned negatives. Modern film developing machines automatically crop one half of an inch off from each image -- the rumor is that the photo printing machines match a certain style of camera view.
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GNU Image Manipulation Program 51 / 653 Indexed - This is the mode usually used when file size is of concern, or when you are working with images with few colours. It involves using a fixed number of colours, 256 or less, at each point to represent the colour at that point. The defaults to attempting to figure out an "optimum palette" to best represent your image. Try it, you can undo it if you don’t like the results, or use a custom palette or more colours. Figure 3.
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GNU Image Manipulation Program 52 / 653 Figure 3.29: Add Alpha Channel Grayscale - In case you want to convert your brilliant colour image to something that’s black and white (with a lot of shades of grey), this is one of the easiest ways in which to do it. Some photos do look a lot fancier when displayed in grayscale. Again, if you’re interested in some detail, this is achieved by taking the RGB values at the pixels in your image, and suitably weighted averaging them to get an intensity at that point.
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GNU Image Manipulation Program 53 / 653 When you need the person in the photo looking in the other direction, or you need the top of the image to be the bottom. Mirroring the image (sort of). Right click on the image and follow the menus Tools → Transform Tools → Flip, or use the on the toolbox. button Using another APOD image [APOD07] I demonstrated all of the flips on this image. You might get bored before it is over ....
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GNU Image Manipulation Program 54 / 653 The invention called the typewriter introduced the Shift Key. You generally have 2 of them on your keyboard. They look something like the picture on the left. They are located on the left and right sides of your keyboard. The other invention, called the Mouse, was invented by Douglas C. Engelbart in 1970. These come in different varieties, but always have at least one button located on them. They are located on your desk, or sometimes on a mouse pad. 2.
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GNU Image Manipulation Program 55 / 653 Figure 3.35: Starting point After you click the paintbrush tool, you can click the image. A single dot will appear on the screen. The size of this dot represents the current brush size, which you can change in the Brush Dialog (see Section 13.3.2). Now, lets start drawing a line. Hold down the Shift button, and keep it down. 5. D RAWING THE L INE Figure 3.
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GNU Image Manipulation Program 56 / 653 3.5.2.1 Examples Figure 3.37: Examples I (a) This one I turned on gradient in (b) This one I used the Clone tool, the Paint Brush Tool. and set the source to "Maple Leaves" pattern. Figure 3.38: Examples II (a) This one I rendered a grid, and (b) This one I rendered a plasma then used the Smudge Tool with a low cloud, and used the Erase Tool with spacing and a slightly larger brush. a square brush. Figure 3.
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GNU Image Manipulation Program 57 / 653 Chapter 4 Getting Unstuck 4.1 4.1.1 Getting Unstuck Stuck! All right, okay: you’re stuck. You’re trying to use one of the tools on an image, and nothing is happening, and nothing you try makes any difference. Your fists are starting to clench, and your face is starting to feel warm. Are you going to have to kill the program, and lose all your work? This sucks! Well, hold on a second.
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GNU Image Manipulation Program 58 / 653 How to solve: Either anchor the floating selection, or convert it into an ordinary (non-floating) layer. If you need help on how to do this, see Floating Selections. The selection is hidden Figure 4.2: Unstuck show selection menu In the View menu, make sure that "Show Selection" is checked.
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GNU Image Manipulation Program 59 / 653 that you wanted to keep, so why have you gotten this far in the first place? If you can see a selection but thought you were inside it, it might be inverted from what you think. The easiest way to tell is to hit the Quick Mask button: the selected area will be clear and the unselected area will be masked. If this was the problem, then you can solve it by toggling Quick Mask off and choosing Invert in the Select menu. The active drawable is not visible Figure 4.
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GNU Image Manipulation Program 60 / 653 Figure 4.5: Unstuck layer transparency Layers dialog with opacity set to zero for the active layer. How to fix: Move the slider. You are trying to act outside the layer How to tell: In GIMP, layers don’t need to have the same dimensions as the image: they can be larger or smaller. If you try to paint outside the borders of a layer, nothing happens.
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GNU Image Manipulation Program 61 / 653 Part II How do I Become a GIMP Wizard?
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GNU Image Manipulation Program 62 / 653 Chapter 5 Getting Images Into GIMP This chapter is about getting images into GIMP. It explains how to create new images, how to load images from files, how to scan them and how to make screenshots. But in the first place we want to introduce you to the general structure of images in GIMP. 5.
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GNU Image Manipulation Program 63 / 653 Essentially the difference between a grayscale image and an RGB image is the number of ‘color channels’: a grayscale image has one; an RGB image has three. An RGB image can be thought of as three superimposed grayscale images, one colored red, one green, and one blue. Actually, both RGB and grayscale images have one additional color channel, called the alpha channel, representing opacity.
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GNU Image Manipulation Program 64 / 653 Note If you are trying to use a filter on an image, and it appears grayed out in the menu, usually the cause is that the image (or, more specifically, the layer) you are working on is the wrong type. Many filters can’t be used on indexed images. Some can be used only on RGB images, or only on grayscale images. Some also require the presence or absence of an alpha channel. Usually the fix is to convert the image to a different type, most commonly RGB. 5.
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GNU Image Manipulation Program 65 / 653 Figure 5.4: The ‘File Open’ dialog. GIMP 2.2 introduced a new File Chooser that provides several features to help you navigate quickly to the file you are looking for. Perhaps the most important is the ability to create ‘bookmarks’ for folders that you use often. Your list of bookmarks appears on the left side of the dialog. The ones at the top ( ‘Home’, ‘Desktop’, etc) come automatically; the others you create using the ‘Add’ button at the bottom of the list.
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GNU Image Manipulation Program 66 / 653 Figure 5.5: The ‘Open Location’ dialog. The Open Location dialog. 5.3.3 Open Recent If the image is one that you previously created using GIMP, perhaps the easiest way to open it is from the menu, using File → Open Recent. This gives you a scrollable list of the images you have most recently worked on in, with icons beside them. You need only select the one you want, and it will be opened. 5.3.
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GNU Image Manipulation Program 67 / 653 Chapter 6 Getting images out of GIMP 6.1 Files The GIMP is capable of reading and writing a large variety of graphics file formats. With the exception of GIMP’s native XCF file type, file handling is done by Plugins. Thus, it is relatively easy to extend GIMP to new file types when the need arises. Not all file types are equally good for all purposes. This part of the documentation should help you understand the advantages and disadvantages of each type. 6.1.
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GNU Image Manipulation Program 68 / 653 Figure 6.1: Example of an Export dialog As stated above, there is no file format, with the exception of GIMP’s native XCF format, that is capable of storing all the data in a GIMP image. When you ask to save an image in a format that will not completely represent it, GIMP notifies you of this, tells you what kind of information will be lost, and asks you whether you would like to ‘export’ the image in a form that the file type can handle.
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GNU Image Manipulation Program 69 / 653 Delay between frames if unspecified Delay between frames if unspecified : you can set the delay, in millisecondes, between frames if it has not been set before. In this case, you can modify every delay in the Layer Dialog. Frame disposal when unspecified Frame disposal when unspecified : If this has not been set before, you can set how frames will be superimposed.
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GNU Image Manipulation Program 70 / 653 in many cases it is possible to set the quality substantially lower without noticably degrading the image. You can test the effect of different quality settings by checking Show Preview in image window in the JPEG dialog. Checking this option causes each change in quality (or any other JPEG parameter) to be shown in the image display. (This does not alter the image, though: it reverts back to its original state when the JPEG dialog is closed.
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GNU Image Manipulation Program 71 / 653 Interlacing Interlacing: When this option is checked, the image is progressively displayed on a Web page. So, slow computer users can stop downloading if they are not interested. Save background color Save background color: If your image has many transparency levels, the Internet browsers which recognize only two levels, will use the background color of your Toolbox instead. But Internet Explorer does not use these informations.
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GNU Image Manipulation Program 72 / 653 Compression This option give you the opportunity to choose the compression method that is appropriate for your image: • None : fast method, but resulting in a big file. • LZW : The image will be compressed using the ‘Lempel-Ziv-Welch’ algorithm, a lossless compression technique. This is an old method, still efficient and fast. More informations at [WKPD-LZW]. • Pack Bits : PackBits is a fast, simple compression scheme for run-length encoding of data.
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GNU Image Manipulation Program 73 / 653 3. After you have flattened the image, you are able to save the image in PNG format for your web site. Note You can save your image in PNG format with the default settings, but using maximum compression. Doing this will have no negative affects on the quality of the picture, as it would have with JPEG format. If your image is a photograph with lots of colors, you would be better off saving it as jpeg.
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GNU Image Manipulation Program 74 / 653 Figure 6.8: The Wilber Image Opened in RGBA Mode. 2. To save an image with alpha transparency, you must have an alpha channel. To check if the image has an alpha channel, go to the channel dialog and verify that an entry for ‘Alpha’ exists, besides Red, Green and Blue. If this is not the case, add a new alpha channel from the layers menu. 3.
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GNU Image Manipulation Program 75 / 653 Chapter 7 Painting with GIMP 7.1 The Selection Often when you operate on an image, you only want part of it to be affected. In GIMP, you make this happen by selecting that part. Each image has a selection associated with it. Most, but not all, GIMP operations act only on the selected portions of the image. Figure 7.
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GNU Image Manipulation Program 76 / 653 selected parts of the image inside, and the unselected parts outside. This concept of the selection is okay for many purposes, but it is not really correct. Actually the selection is implemented as a channel. In terms of its internal structure, it is identical to the red, green, blue, and alpha channels of an image. Thus, the selection has a value defined at each pixel of the image, ranging between 0 (unselected) and 255 (fully selected).
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GNU Image Manipulation Program 77 / 653 Note For technically oriented readers: feathering works by applying a Gaussian blur to the selection channel, with the specified blurring radius. 7.1.2 Making a Selection Partially Transparent You can set layer opacity, but you cannot do that directly for a selection. It is quite useful to make the image of a glass transparent. You can achieve this by using these methods: • For simple selections, use the Eraser tool with the wanted opacity.
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GNU Image Manipulation Program 78 / 653 7.2 7.2.1 Creating and Using Selections Moving a Selection Figure 7.5: Moving the Selection Reveals the Background Layer After creating a rectangular, elliptic or free selection, or when you are using the Magic wand, the default mouse pointer is the moving cross. Click-and-drag then allows you to move the selection and its contents, while the initial position remains empty.
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GNU Image Manipulation Program 79 / 653 7.2.2 Creating a Free Selection Figure 7.6: Using the Free Selection Tool (a) A rather rough (b) Adding new selected areas to selection an existing selection. When using the lasso to select an object, some parts of the object and its proximity may be incorrectly either selected or not selected. You can correct these defects by pressing the Shift or Ctrl keys while using the lasso.
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GNU Image Manipulation Program 80 / 653 marching-ant mode. You can also activate the QuickMask by selecting in the image window menu Select → Toggle QuickMask, or by using the Shift-Q shortcut. Activating the QuickMask shows you the selection as though it were a translucent screen overlying the image, whose transparency at each pixel indicates the degree to which that pixel is selected. By default the mask is shown in red, but you can change this if another mask color would be more convenient.
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GNU Image Manipulation Program 81 / 653 7.5 Paths Paths are curves (known as Bézier-curves). In GIMP it’s very easy to learn and to use them. To understand their concepts and mechanism you can go to the glossary Bézier-curve or to Wikipedia http://en.wikipedia.org/wiki/Bézier_curve. It is a very powerful tool to design sophisticated forms. To use it in GIMP you must operate by two successive ways: 1st Create the path and 2nd Stroke path.
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GNU Image Manipulation Program 82 / 653 Figure 7.9: Appearance of a path while it is being manipulated using the Path tool. Black squares are anchor points, the open circle is the selected anchor, and the two open squares are its handles. Note that this path has two components. Paths can be created and manipulated using the Path tool. Paths, like layers and channels, are components of an image. When an image is saved in GIMP’s native XCF file format, any paths it has are saved along with it.
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GNU Image Manipulation Program 83 / 653 path is transformed back into a selection, the result is an all-or-none selection, similar to what would be obtained by executing "Sharpen" from the Select menu. 7.5.3 Transforming Paths Each of the Transform tools (Rotate, Scale, Perspective, etc) can be set to act specifically on paths, using the ‘Affect:’ option in the tool’s Tool Options dialog.
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GNU Image Manipulation Program 84 / 653 Figure 7.11: The Stroke Path dialog. You can further increase the range of stroking effects by stroking a path multiple times, or by using lines or brushes of different widths. The possibilities for getting interesting effects in this way are almost unlimited. 7.5.5 Paths and Text Figure 7.12: Text converted to a path (a) Text converted to a path and then trans- (b) The path shown above, stroked with a formed using the Perspective tool.
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GNU Image Manipulation Program 85 / 653 7.5.6 Paths and SVG files SVG, standing for ‘Scalable Vector Graphics’, is an increasingly popular file format for vector graphics, in which graphical elements are represented in a resolution-independent format, in contrast to raster graphics; in which graphical elements are represented as arrays of pixels. GIMP is mainly a raster graphics program, but paths are vector entities.
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GNU Image Manipulation Program 86 / 653 GIMP can use several different types of brushes. All of them, however, are used in the same way, and for most purposes you don’t need to be aware of the differences when you paint with them. Here are the available types of brushes: Ordinary brushes Most of the brushes supplied with GIMP fall into this category. They are represented in the Brushes dialog by grayscale pixmaps.
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GNU Image Manipulation Program 87 / 653 GIH The .gih ("gimp image hose") format is used for animated brushes. These brushes are constructed from images containing multiple layers: each layer may contain multiple brush-shapes, arranged in a grid. When you save an image as a .gih file, a dialog comes up that allows you to describe the format of the brush. Look at The GIH dialog box for more information about the dialog.
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GNU Image Manipulation Program 88 / 653 Spacing (Percent) "Spacing" is the distance between consecutive brush marks when you trace out a brushstroke with the pointer. You must consider drawing with a brush, whatever the paint tool, like stamping. If Spacing is low, stamps will be very close and stroke look continuous. If spacing is high, stamps will be separated: that’s interesting with a color brush (like "green pepper" for instance).
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GNU Image Manipulation Program 89 / 653 direction change: second rank will be affected to 270 (-90) (leftwards), third rank to 180 (downwards) and fourth rank to 90 (rightwards). • Speed, Pressure, x tilt and y tilt are options for sophisticated drawing tablets. E XAMPLES A one dimension image pipe Well! What is all this useful for? We’ll see that gradually with examples. You can actually place in each dimension cases that will give your brush a particular action.
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GNU Image Manipulation Program 90 / 653 1. Creating images of dimension 1 (x): Open a new 30x30 pixels image, RGB with Transparent Fill Type. Using the zoom draw a left hand with fingers upwards. Save it as handL0k.xcf (hand Left O Black). Open the Layer Dialog. Double click on the layer to open the Layer Attributes Dialog and rename it to handL0k. Duplicate the layer. Let visible only the duplicated layer, select it and apply a 90 rotation (Layer/Transform/ 90 rotation counter-clockwise).
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GNU Image Manipulation Program 91 / 653 5. Voilà. Your brush is ready. Save it as .xcf first then as .gih with the following parameters: Spacing:100 Description:Hands Cell Size: 30x30 Number of cells:16 Dimensions: 3 • Dimension 1: 4 ranks Selection: Angular • Dimension 2: 2 ranks Selection: Incremental • Dimension 3: 2 ranks Selection: Random Place your .gih file into GIMP brush directory and refresh the brush box. You can now use your brush. Figure 7.
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GNU Image Manipulation Program 92 / 653 2. Click on the New Brush button to open the Brush Editor dialog. Name your brush at once, ‘Dynamic’ for instance. Your brush will appear in the Brush Dialog with a blue corner. 3. Now, go to File → Preferences → Input Controllers. • Check the Enable this controller box. • Scroll through the Events list and select Scroll up (Shift). Avoid Scroll up (Ctrl) because Ctrl is yet used by tools to turn to the Color Picker mode.
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GNU Image Manipulation Program 93 / 653 The Gradient Map filter This filter allows you to ‘colorize’ a grayscale image, by replacing each shade of gray with the corresponding color from a gradient. See Section 15.3.8 for more information. When you install GIMP, it comes presupplied with a large number of interesting gradients, and you can add new ones that you create or download from other sources.
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GNU Image Manipulation Program 94 / 653 7.11 Patterns A pattern is an image, usually small, used for filling regions by tiling, that is, by placing copies of the pattern side by side like ceramic tiles. A pattern is said to be tileable if copies of it can be adjoined left-edge-to-right-edge and top-edge-to-bottom-edge without creating obvious seams. Not all useful patterns are tileable, but tileable patterns are nicest for many purposes. (A texture, by the way, is the same thing as a pattern.) Figure 7.
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GNU Image Manipulation Program 95 / 653 To make a pattern available, you place it in one of the folders in GIMP’s pattern search path. By default, the pattern search path includes two folders, the system patterns folder, which you should not use or alter, and the patterns folder inside your personal GIMP directory. You can add new folders to the pattern search path using the Pattern Folders page of the Preferences dialog. Any PAT file (or, in GIMP 2.
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GNU Image Manipulation Program 96 / 653 Figure 7.20: The Palettes dialog When you install GIMP, it comes supplied with several dozen predefined palettes, and you can also create new ones. Some of the predefined palettes are commonly useful, such as the ‘Web’ palette, which contains the set of colors considered ‘web safe’; many of the palettes seem to have been chosen more or less whimsically. You can access all of the available palettes using the Palettes dialog.
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GNU Image Manipulation Program 97 / 653 allowed in an indexed palette is 256. These palettes are called ‘indexed’ because each color is associated with an index number. (Actually, the colors in ordinary palettes are numbered as well, but the numbers have no functional significance.) Figure 7.22: The Colormap dialog The colormap of an indexed image is shown in the Indexed Palette dialog, which should not be confused with the Palettes dialog.
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GNU Image Manipulation Program 98 / 653 Create a new image. Select your favorite painting tool or use the pencil, if in doubt. Select a foreground color, but be sure that the foreground and background colors are different. Figure 7.24: The dialog shows a new image, with the first dot which indicates the start of the straight line. The dot has a black foreground color. 2. Create a starting point by clicking on the image display area with the left mouse button. Your canvas should look similar to Figure 7.
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GNU Image Manipulation Program 99 / 653 shape, but we’ll stick to the easiest ones here. So, create a new image and check that the foreground and background colors are different. Figure 7.27: The screenshot shows how a rectangular selection is created. Press and hold the left mouse button while you move the mouse in the direction of the red arrow. 2. Basic shapes like rectangles or ellipses, can be created using the selection tools. This tutorial uses a rectangular selection as an example.
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GNU Image Manipulation Program 100 / 653 Chapter 8 Combining Images 8.1 Introduction to Layers A good way to visualize a GIMP image is as a stack of transparencies: in GIMP terminology, each individual transparency is called a layer. There is no limit, in principle, to the number of layers an image can have: only the amount of memory available on the system. It is not uncommon for advanced users to work with images containing dozens of layers.
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GNU Image Manipulation Program 101 / 653 command Layer → Transparency → Add Alpha Channel, or by right-clicking in the Layers dialog and selecting Add Alpha Channel from the popup menu that appears. Example for Alpha channel Figure 8.1: Alpha channel example: Basic image This image has three layers painted with pure 100% opaque Red, Green, and Blue. In the Channel Dialog, you can see that an alpha Channel has been added.
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GNU Image Manipulation Program 102 / 653 Figure 8.4: Alpha channel example: Three layers transparent The left part of the third layer has been made transparent. The Alpha channel is still white and the left part of the layer is white, opaque! The background layer has no Alpha channel. In this case, the Clear command works like the Eraser and uses the Background color of Toolbox. Figure 8.
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GNU Image Manipulation Program 103 / 653 Tip If you Shift-click on the eye symbol, this will cause all layers except the one you click on to be hidden. Linkage to other layers If you click between the eye icon and the layer thumbnail, you get a chain icon ( ), which enables you to group layers for operations on multiple layers (for example with the Move tool or a transform tool). Size In GIMP, the boundaries of a layer do not necessarily match the boundaries of the image that contains it.
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GNU Image Manipulation Program 104 / 653 Layer modes permit complex color changes in the image. They are often used with a new layer which acts as a kind of mask. For example, if you put a solid white layer over an image and set the layer mode of the new layer to ‘Saturation’, the underlying visible layers will appear in shades of gray. Figure 8.6: Images (masks) for layer mode examples (a) Mask 1 (b) Mask 2 Figure 8.
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GNU Image Manipulation Program 105 / 653 Since the results of each mode vary greatly depending upon the colors on the layers, these images can only give you a general idea of how the modes work. You are encouraged to try them out yourself. You might start with two similar layers, where one is a copy of the other, but slightly modified (by being blurred, moved, rotated, scaled, color-inverted, etc.) and seeing what happens with the layer modes. Normal Figure 8.
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GNU Image Manipulation Program 106 / 653 Dissolve mode dissolves the upper layer into the layer beneath it by drawing a random pattern of pixels in areas of partial transparency. It is useful as a layer mode, but it is also often useful as a painting mode. This is especially visible along the edges within an image. It is easiest to see in an enlarged screenshot.
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GNU Image Manipulation Program 107 / 653 Figure 8.11: Example for layer mode ‘Divide’ (a) Mask 1 is used as upper layer with 100% opac- (b) Mask 2 is used as upper layer with 100% opacity. ity. Divide mode multiplies each pixel value in the lower layer by 256 and then divides that by the corresponding pixel value of the upper layer plus one. (Adding one to the denominator avoids dividing by zero.) The resulting image is often lighter, and sometimes looks ‘burned out’.
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GNU Image Manipulation Program 108 / 653 E = 1 − (255−M)∗(255−I) 255 E QUATION 8.5: Equation for layer mode Screen The mode is commutative; the order of the two layers doesn’t matter. Overlay Figure 8.13: Example for layer mode ‘Overlay’ (a) Mask 1 is used as upper layer with 100% opac- (b) Mask 2 is used as upper layer with 100% opacity. ity.
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GNU Image Manipulation Program 109 / 653 Figure 8.14: Example for layer mode ‘Dodge’ (a) Mask 1 is used as upper layer with 100% opac- (b) Mask 2 is used as upper layer with 100% opacity. ity. Dodge mode multiplies the pixel value of the lower layer by 256, then divides that by the inverse of the pixel value of the top layer. The resulting image is usually lighter, but some colors may be inverted.
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GNU Image Manipulation Program 110 / 653 In photography, burning is a technique used in a darkroom to decrease the exposure in particular areas of the image. This brings out details in the highlights. When used for this purpose, burn may work best on Grayscale images and with a painting tool, rather than as a layer mode. The equation is: E = 255 − (255−I)∗256 M+1 E QUATION 8.8: Equation for layer mode Burn Hard light Figure 8.
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GNU Image Manipulation Program 111 / 653 Figure 8.17: Example for layer mode ‘Soft light’ (a) Mask 1 is used as upper layer with 100% opac- (b) Mask 2 is used as upper layer with 100% opacity. ity. Soft light is not related to ‘Hard light’ in anything but the name, but it does tend to make the edges softer and the colors not so bright. It is similar to ‘Overlay’ mode. In some versions of GIMP, ‘Overlay’ mode and ‘Soft light’ mode are identical. The equation is complicated.
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GNU Image Manipulation Program 112 / 653 also be useful for giving images an embossed appearance. It subtracts the pixel value of the upper layer from that of the lower layer and adds 128. The equation is: E = I − M + 128 E QUATION 8.13: Equation for layer mode Grain extract Grain merge Figure 8.19: Example for layer mode ‘Grain merge’ (a) Mask 1 is used as upper layer with 100% opac- (b) Mask 2 is used as upper layer with 100% opacity. ity.
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GNU Image Manipulation Program 113 / 653 Figure 8.20: Example for layer mode ‘Difference’ (a) Mask 1 is used as upper layer with 100% opac- (b) Mask 2 is used as upper layer with 100% opacity. ity. Difference mode subtracts the pixel value of the upper layer from that of the lower layer and then takes the absolute value of the result. No matter what the original two layers look like, the result looks rather odd. You can use it to invert elements of an image. The equation is: E = |I − M| E QUATION 8.
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GNU Image Manipulation Program 114 / 653 The equation is: E = min((M + I), 255) E QUATION 8.16: Equation for layer mode Addition The mode is commutative; the order of the two layers doesn’t matter. Subtract Figure 8.22: Example for layer mode ‘Subtract’ (a) Mask 1 is used as upper layer with 100% opac- (b) Mask 2 is used as upper layer with 100% opacity. ity. Subtract mode subtracts the pixel values of the upper layer from the pixel values of the lower layer. The resulting image is normally darker.
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GNU Image Manipulation Program 115 / 653 Figure 8.23: Example for layer mode ‘Darken only’ (a) Mask 1 is used as upper layer with 100% opac- (b) Mask 2 is used as upper layer with 100% opacity. ity. Darken only mode compares each component of each pixel in the upper layer with the corresponding one in the lower layer and uses the smaller value in the resulting image. Completely white layers have no effect on the final image and completely black layers result in a black image.
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GNU Image Manipulation Program 116 / 653 The equation is: E = max(M, I) E QUATION 8.19: Equation for layer mode Lighten only The mode is commutative; the order of the two layers doesn’t matter. Hue Figure 8.25: Example for layer mode ‘Hue’ (a) Mask 1 is used as upper layer with 100% opac- (b) Mask 2 is used as upper layer with 100% opacity. ity. Hue mode uses the hue of the upper layer and the saturation and value of the lower layer to form the resulting image.
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GNU Image Manipulation Program 117 / 653 Color Figure 8.27: Example for layer mode ‘Color’ (a) Mask 1 is used as upper layer with 100% opac- (b) Mask 2 is used as upper layer with 100% opacity. ity. Color mode uses the hue and saturation of the upper layer and the value of the lower layer to form the resulting image. Value Figure 8.28: Example for layer mode ‘Value’ (a) Mask 1 is used as upper layer with 100% opac- (b) Mask 2 is used as upper layer with 100% opacity. ity.
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GNU Image Manipulation Program 118 / 653 Figure 8.29: Multi layer example GIMP also has similar modes which are used for the painting tools. These are the same twenty-one modes as the layer modes, plus an additional two modes which are specific to the painting tools. You can set these modes from the Mode menu in the Tools option dialog. In the equations shown above, the layer you are painting on is the ‘lower layer’ and the pixels painted by the tool are the ‘upper layer’.
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GNU Image Manipulation Program 119 / 653 8.4 Text and Fonts Figure 8.30: Example of a text item Example of a text item, showing the boundary of the text layer. (Font: Utopia Bold) One of the greatest improvements of GIMP 2.0 over GIMP 1.2 is in the handling of text. In GIMP 2.0 and 2.2, each text item goes in a separate Text layer, and you can come back later to the layer and edit the text in it. You can also move the text around in the image, or change the font, or the font size.
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GNU Image Manipulation Program 120 / 653 8.5 8.5.1 Text Embellishing Text Figure 8.32: Fancy text Four fancy text items created using logo scripts: alien neon, bovination, frosty, and chalk. Default settings were used for everything except font size. There are many things you can do to vary the appearance of text beyond just rendering it with different fonts or different colors.
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GNU Image Manipulation Program 121 / 653 • Windows FNT fonts • BDF fonts (including anti-aliased ones) • PFR fonts • Type42 fonts (limited support) You can also add modules to support other types of font files. See FREETYPE 2 [FREETYPE] for more information. Linux On a Linux system, if the Fontconfig utility is set up as usual, all you need to do to add a new font is to place the file in the directory ~/.fonts.
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GNU Image Manipulation Program 122 / 653 Chapter 9 Enhancing Photographs 9.1 9.1.1 Working with Digital Camera Photos Introduction One of the most common uses of the GIMP is to fix digital camera images that for some reason are less than perfect. Maybe the image is overexposed or underexposed; maybe rotated a bit; maybe out of focus: these are all common problems for which GIMP has good tools.
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GNU Image Manipulation Program 123 / 653 Note Note: New in GIMP 2.2 is the option to preview the results of transformations, instead of just seeing a grid. This makes it easier to get things right on the first try. After you have rotated an image, there will be unpleasant triangular "holes" at the corners. One way to fix them is to create a background that fills the holes with some unobtrusive or neutral color, but usually a better solution is to crop the image.
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GNU Image Manipulation Program 124 / 653 If you can find a point in the image that ought to be perfect white, and a second point that ought to be perfect black, then you can use the Levels tool to do a semi-automatic adjustment that will often do a good job of fixing both brightness and colors throughout the image. First, bring up the Levels tool as previously described.
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GNU Image Manipulation Program 125 / 653 In addition to ‘Multiply’ and ‘Divide’, you may every so often get useful effects with other layer combination modes, such as ‘Dodge’, ‘Burn’, or ‘Soft Light’. It is all too easy, though, once you start playing with these things, to look away from the computer for a moment and suddenly find that you have just spent an hour twiddling parameters. Be warned: the more options you have, the harder it is to make a decision. 9.1.3.
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GNU Image Manipulation Program 126 / 653 Next to "Unsharp Mask" in the Filters menu is another filter called Sharpen, which does similar things. It is a little easier to use but not nearly as effective: our recommendation is that you ignore it and go straight to Unsharp Mask. In some situations, you may be able to get useful results by selectively sharpening specific parts of an image using the Blur or Sharpen tool from the Toolbox, in "Sharpen" mode.
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GNU Image Manipulation Program 127 / 653 Consult the Clone Tool Help for more detailed instructions. Cloning is as much an art as a science, and the more you practice at it, the better you will get. At first it may seem impossible to produce anything except ugly blotches, but persistence will pay off. In some cases you may be able to get good results by simply cutting out the offending object from the image, and then using a plug-in called ‘Resynthesizer’ to fill in the void.
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GNU Image Manipulation Program 128 / 653 9.1.6.2 Printing Your Photos As in most softwares, in GIMP, printing needs to go to main menu File → Print. However it is very usefull to keep in mind some elementary concepts to prevent some unpleasant surprises when looking at result, or to cure them if that occurs.
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GNU Image Manipulation Program 129 / 653 Chapter 10 Pimp my GIMP 10.1 Grids and Guides You will probably have it happen many times that you need to place something in an image very precisely, and find that it is not easy to do using a mouse. Often you can get better results by using the arrow keys on the keyboard (which move the affected object one pixel at a time, or 25 pixels if you hold down the Shift key), but GIMP also provides you with two other aids to make positioning easier: grids and guides.
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GNU Image Manipulation Program 130 / 653 10.1.1 The Image Grid Figure 10.2: Image with default grid Each image has a grid. It is always present, but by default it is not visible until you activate it by toggling View → Show Grid in the image menu. If you want grids to be present more often than not, you can change the default behavior by checking "Show grid" in the Image Window Appearance page of the Preferences dialog. (Note that there are separate settings for Normal Mode and Fullscreen Mode.
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GNU Image Manipulation Program 131 / 653 10.1.2 Guides Figure 10.4: Image with four guides In addition to the image grid, GIMP also gives you a more flexible type of positioning aid: guides. These are horizontal or vertical lines that you create by clicking on one of the rulers and dragging into the image. You can create as many guides as you like, positioned whereever you like.
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GNU Image Manipulation Program 132 / 653 the work on the pictures fast and comfortable for the user. That Data memory, during the treatment, is organized in buffered blocks of graphic data, wich could exists in two different form of data memory: in the slow not removable disk or in the fast main RAM memory. GIMP uses preferibly the last one but, when it is scarse, the first is accessed for the remaining data.
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GNU Image Manipulation Program 133 / 653 As you can see, all is about checking the free resources, and decide if the OS swap is worth using or will cause more problems than help. There are some reasons you want to adjust this value, though. The basic one is changes in your computer usage pattern, or changing hardware. That could mean your assumptions about how you use your computer, or the speed of it, are no longer valid.
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GNU Image Manipulation Program 134 / 653 Figure 10.5: Configure Keyboard Shortcuts 1. You get to this Editor by clicking on Configure keyboard shortcuts in the ‘Interface’ item of the Preferences menu. 2. As shown in this dialog, you can select the command you want to create a shortcut for, in the ‘Action’ area. Then you type your key sequence as above. In principle, the Space bar should clear a shortcut. (In practice, it clears it, but doesn’t delete it.) 3.
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GNU Image Manipulation Program 135 / 653 • The Paths dialog • The Undo dialog Brushes, Patterns and Gradients This gives you a dock containing: • The Brushes dialog • The Patterns dialog • The Gradients dialog • The Palettes dialog • The Fonts dialog Misc. Stuff This gives you a dock containing: • The Buffers dialog • The Images dialog • The Document History dialog • The Image Templates dialog Tip Just because you have a lot of flexibility does not mean that all choices are equally good.
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GNU Image Manipulation Program 136 / 653 If you want to remove a dialog from a dock, there are two ways you can do it. First, if you click on the drag handle area and drag the dialog away, releasing it someplace other than a docking bar, it will form a new dock in its own right. Second, clicking on the ‘Close Tab’ button (highlighted in the figure to the right) will close the frontmost dialog. 10.6 Customize Splash-Screen Open your file browser and check the option ‘Show Hidden Files’.
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GNU Image Manipulation Program 137 / 653 Chapter 11 Scripting 11.1 Plugins 11.1.1 Introduction One of the nicest things about GIMP is how easily its functionality can be extended, by using plugins. GIMP plugins are external programs that run under the control of the main GIMP application and interact with it very closely. Plugins can manipulate images in almost any way that users can.
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GNU Image Manipulation Program 138 / 653 Caution Plugins have been a feature of GIMP for many versions. However, plugins written for one version of GIMP can hardly ever be used successfully with other versions. They need to be ported: sometimes this is easy, sometimes not. Many plugins are already available in several versions. Bottom line: before trying to install a plugin, make sure that it is written for your version of GIMP. 11.1.
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GNU Image Manipulation Program 139 / 653 Xtns/Plugins Details) search the plug-in by its name and look ot the Tree view tab. If you still don’t find, finally explore the menus or look at the source code in the Register section -- whichever is easiest. For more complex plugins, organized as a directory with multiple files, there ought to be a file inside called either INSTALL or README, with instructions.
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GNU Image Manipulation Program 140 / 653 things with Script-Fu, but an ordinary GIMP user will probably use it for automating things that: • You want to do frequently. • Are really complicated to do, and hard to remember. Remember that you can do a whole lot with Script-Fu. The scripts that come with GIMP can be quite useful, but they can also serve as models for learning Script-Fu, or at least as a framework and source of modification when you make your own script.
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GNU Image Manipulation Program 141 / 653 • Misc. Patterns You will find all kinds of pattern-generating scripts here. Generally, they are quite useful because you can add many arguments to your own patterns. We’ll take a look at the Land script. In this script you have to set the image/pattern size, and specify what levels of random to use for your land creation. The colors used to generate the land map are taken from the currently selected gradient in the gradient editor.
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GNU Image Manipulation Program 142 / 653 11.2.6 Image-Dependent Scripts These are scripts that perform operations on an existing image. In many ways they are like the plug-ins in the Filters menu. The following script groups are installed by default: • Alchemy • Alpha to logo • Animators • Decor • Render • Selection • Shadow • Stencil Ops • Utils Stencil Ops Here, you’ll find two scripts: Carve-It and Chrome-It, which can render some truly nice artistic effects on grayscale images.
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GNU Image Manipulation Program 143 / 653 The second thing you need to know is that: The function name/operator is always the first item in the parentheses, and the rest of the items are parameters to the function. El nombre de función/operadores, siempre, lo primero en los paréntesis, y el resto son parámetros de la función. However, not everything enclosed in parentheses is a function -- they can also be items in a list -- but we’ll get to that later.
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GNU Image Manipulation Program 144 / 653 Knowing that the + operator can take a list of numbers to add, you might be tempted to convert the above to the following: (+ 3 (5 6) 7) However, this is incorrect -- remember, every statement in Scheme starts and ends with parens, so the Scheme interpreter will think that you’re trying to call a function named ‘5’ in the second group of parens, rather than summing those numbers before adding them to 3.
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GNU Image Manipulation Program 145 / 653 11.3.2.2 What Is A Local Variable? You’ll notice that we wrote the summation (+ a b) within the parens of the let* expression, not after it. This is because the let* statement defines an area in your script in which the declared variables are usable; if you type the (+ a b) statement after the (let* ...
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GNU Image Manipulation Program 146 / 653 (define (AddXY inX inY) (+ inX inY) ) AddXY is the function’s name and inX and inY are the variables. This function takes its two parameters and adds them together. If you’ve programmed in other imperative languages (like C/C++, Java, Pascal, etc.), you might notice that a couple of things are absent in this function definition when compared to other programming languages.
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GNU Image Manipulation Program 147 / 653 or simply: () Lists can contain atomic values, as well as other lists: (let* ( (x ’("The GIMP" (1 2 3) ("is" ("great" () ) ) ) ) ) x ) Notice that after the first apostrophe, you no longer need to use an apostrophe when defining the inner lists. Go ahead and copy the statement into the Script-Fu Console and see what it returns.
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GNU Image Manipulation Program 148 / 653 11.3.3.5 Accessing Values In A List To access the values in a list, use the functions car and cdr, which return the first element of the list and the rest of the list, respectively. These functions break the list down into the head::tail construct I mentioned earlier. 11.3.3.6 The car Function car returns the first element of the list (the head of the list). The list needs to be non-null.
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GNU Image Manipulation Program 149 / 653 (let* ( (x ) ’( (1 2 (3 4 5) 6) 7 8 (9 10) ) ) ; place your car/cdr code here ) Try accessing the number 3 in the list using only two function calls. If you can do that, you’re on your way to becoming a Script-Fu Master! Note In Scheme, a semicolon (";") marks a comment. It, and anything that follows it on the same line, are ignored by the script interpreter, so you can use this to add comments to jog your memory when you look at the script later. 11.3.
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GNU Image Manipulation Program 150 / 653 11.3.4.4 Naming Conventions Scheme’s naming conventions seem to prefer lowercase letters with hyphens, which I’ve followed in the naming of the function. However, I’ve departed from the convention with the parameters. I like more descriptive names for my parameters and variables, and thus add the "in" prefix to the parameters so I can quickly see that they’re values passed into the script, rather than created within it.
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GNU Image Manipulation Program 151 / 653 If your script is intended to work on an image being edited, you’ll want to insert it in the menu that appears when you rightclick on an open image. The rest of the path points to the menu lists, menus and sub-menus. Thus, we registered our Text Box script in the Text menu of the Script-Fu menu of the Xtns menu of the toolbox ( Xtns → Script-Fu → Text → Text Box ).
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GNU Image Manipulation Program 152 / 653 DB Browser and let’s get cookin’! Let’s begin by making a new image. We’ll create a new variable, theImage, set to the result of calling GIMP’s built-in function gimp-image-new. As you can see from the DB Browser, the function gimp-image-new takes three parameters -- the image’s width, height and the type of image. Because we’ll later resize the image to fit the text, we’ll make a 10x10 RGB image.
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GNU Image Manipulation Program 153 / 653 (gimp-display-new theImage) Save your work, select Xtns → Script-Fu → Refresh Scripts, run the script and a new image should pop up. It will probably contain garbage (random colors), because we haven’t erased it. We’ll get to that in a second. 11.3.5.3 Adding The Text Go ahead and remove the line to display the image (or comment it out with a ; as the first character of the line).
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GNU Image Manipulation Program 154 / 653 11.3.5.4 Clearing The Dirty Flag If you try to close the image created without first saving the file, GIMP will ask you if you want to save your work before you close the image. It asks this because the image is marked as dirty, or unsaved.
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GNU Image Manipulation Program 155 / 653 ) ) ) (theText) (theBuffer) (theLayer (car ;a declaration for the text ;we create later ;added (gimp-layer-new theImage theImageWidth theImageHeight RGB-IMAGE "layer 1" 100 NORMAL ) ) ) ) ;end of our local variables [Code here] ) (script-fu-register "script-fu-text-box" ;func name "Text Box" ;menu label "Creates a simple text box, sized to fit\ around the user’s choice of text,\ font, font size, and color.
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GNU Image Manipulation Program 156 / 653 (gimp-layer-set-offsets theText theBuffer theBuffer) Go ahead and save your script, and try it out after refreshing the database. All that is left to do is return our image, the layer, and the text layer. After displaying the image, we add this line: (list theImage theLayer theText) This is the last line of the function, making this list available to other scripts that want to use it.
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GNU Image Manipulation Program 157 / 653 Part III Function Reference
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GNU Image Manipulation Program 158 / 653 Chapter 12 Toolbox 12.1 The Toolbox The GIMP provides a comprehensive toolbox in order to quickly perform basic tasks such as making selections or drawing paths. The many tools contained within The GIMP’s toolbox are discussed in detail here. The GIMP has a diverse assortment of tools that let you perform a large variety of tasks.
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GNU Image Manipulation Program 159 / 653 12.1.1 Tool Options Figure 12.1: Tool Options dialog for the Rectangle Select tool. If you have things set up like most people do, activating a tool causes its Tool Options dialog to appear below the Toolbox. If you don’t have things set up this way, you probably should: it is very difficult to use tools effectively without being able to manipulate their options. Tip The Tool Options appear beneath the Toolbox in the default setup.
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GNU Image Manipulation Program 160 / 653 These common features are described here; the variations are explained in the following sections for each tool specifically. If you need help with what a ‘selection’ is in GIMP, and how it works, see Selection.
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GNU Image Manipulation Program 161 / 653 12.2.1.2 Options Here we describe the tool options that apply to all selection tools: options that apply only to some tools, or that affect each tool differently, are described in the sections devoted to the individual tools. The current settings for these options can be seen in the Tool Options dialog, which you should always have visible when you are using tools. (Most users keep it docked directly below the Toolbox.
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GNU Image Manipulation Program 162 / 653 The Rectangle Selection tool is designed to select rectangular regions of an image: it is the most basic of the selection tools, but very commonly used. For information on selections and how they are used in GIMP see Selections; for information on features common to all selection tools see Selection Tools. This tool is also used for rendering a rectangle on an image.
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GNU Image Manipulation Program 163 / 653 12.2.2.3 Tool Options Figure 12.3: Tool Options for the Rectangle Select tool Note See Selection Tools for help with options that are common to all these tools. Only options that are specific to the Rectangle Select tool are explained here. Antialiasing This option performs no function for this tool and is present to unify the user interface between the various selection types.
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GNU Image Manipulation Program 164 / 653 12.2.3 Ellipse Selection Tool Figure 12.5: Ellipse Select icon in the Toolbox The Ellipse Selection tool is designed to select circular and elliptical regions from an image, with high-quality anti-aliasing if you want it. For information on selections and how they are used in GIMP see Selections; for information on features common to all selection tools see Selection Tools. This tool is also used for rendering a circle or ellipse on an image.
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GNU Image Manipulation Program 165 / 653 12.2.3.3 Options Figure 12.6: Tool Options for the Ellipse Select tool Note See Selection Tools for help with options that are common to all these tools. Only options that are specific to the Ellipse Select tool are described here. You can access to the Ellipse Selection options by double-clicking on the icon. Antialiasing Checking this option will make the edge of the selection appear smoother, by partially selecting pixels that the edge passes through.
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GNU Image Manipulation Program 166 / 653 12.2.4 Free Selection Tool (Lasso) Figure 12.8: Free Selection icon in the Toolbox The Free Selection tool, or Lasso, lets you create a selection by drawing it free-hand with the pointer, while holding down the left mouse button (or, for a stylus, pressing it against the tablet). When you release the mouse button, the selection is closed by connecting the current pointer location to the start location with a straight line.
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GNU Image Manipulation Program 167 / 653 12.2.4.3 Options Figure 12.9: Tool Options for the Lasso tool The Free Select tool has no special tool options, only the ones that affect all selection tools in the same way. See Selection Tools for help with these. You can find the lasso options by double-clicking on the 12.2.5 icon in the Toolbox. Fuzzy selection (Magic wand) Figure 12.
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GNU Image Manipulation Program 168 / 653 Note that as the selected area expands outward from the center, it does not only propagate to pixels that touch each other: it is capable of jumping over small gaps. The distance it can jump over is set in the Tool Options page of the Preferences dialog: the "Default threshold" for Finding Continguous Regions. By raising or lowering this value, you can make the Magic Wand either more or less aggressive.
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GNU Image Manipulation Program 169 / 653 12.2.6 Select By Color Tool Figure 12.12: Select by Color tool icon in the Toolbox The Select by Color tool is designed to select areas of an image based on color similarity. It works a lot like the Fuzzy Select tool (‘Magic Wand’).
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GNU Image Manipulation Program 170 / 653 Note See Section 12.2.1 for help with options that are common to all these tools. Only options that are specific to the Select by Color tool are explained here. Note that they are the same options as the Magic Wand tool has. You can find the Magic Wand options by double-clicking on the icon in the Toolbox. Finding Similar Colors These options affect the way the Select by Color tool expands the selection out from the initial point.
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GNU Image Manipulation Program 171 / 653 Warning Be sure not to click inside the curve until you are completely done adjusting it. Once you have converted it into a selection, undoing takes you back to zero, and you will have to to start constructing the curve again from scratch if you need to change it. Also be sure not to switch to a different tool, or again all of your carefully created control nodes will be lost. (But you still can transform your selection into a path and work it with the Path tool.
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GNU Image Manipulation Program 172 / 653 12.3 Brush Tools 12.3.1 Common Features Figure 12.16: The Brush tools The GIMP Toolbox includes nine "brush tools", all grouped together at the bottom (in the default arrangement). The feature they all have in common is that all of them are used by moving the pointer across the image display, creating brushstrokes. Four of them – the Pencil, Paintbrush, Airbrush, and Ink tools – behave like the intuitive notion of "painting" with a brush.
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GNU Image Manipulation Program 173 / 653 12.3.1.2 Tool Options Figure 12.17: Tool Options shared by all brush tools Many tool options are shared by several brush tools: these are described here. Options that apply only to one specific tool, or to a small number of tools, are described in the sections devoted to those tools. Opacity The Opacity slider sets the transparency level for the brush operation.
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GNU Image Manipulation Program 174 / 653 Incremental The Incremental checkbox activates incremental mode for the tool. If it is deactivated, the maximum effect of a single stroke is determined by the opacity, and moving the brush repeatedly over the same spot will not increase the effect beyond this limit. If Incremental is active, each additional pass with the brush will increase the effect, but the opacity can’t exceed the opacity set for the tool.
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GNU Image Manipulation Program 175 / 653 12.3.2.1 Activate Tool • The Bucket Fill can be called in the following order, from the image-menu: Tools/ Paint Tools/Bucket Fill. • The Tool can also be called by clicking the tool icon: 12.3.2.2 Key modifiers (Defaults) Shortcut The Shift-B keys will change the active tool to Bucket Fill. Ctrl toggles the use of BG Color Fill or FG Color Fill on the fly. Shift toggles the use of Fill Similar Color or Fill Whole Selection on the fly. 12.3.2.
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GNU Image Manipulation Program 176 / 653 12.3.3 Gradient Tool Figure 12.19: The Blend tool in Toolbox. This tool fills the selected area with a gradient blend of the foreground and background colors by default, but there are many options. To make a blend, drag the cursor in the direction you want the gradient to go, and release the mouse button when you feel you have the right position and size of your blend. The softness of the blend depends on how far you drag the cursor.
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GNU Image Manipulation Program 177 / 653 12.3.3.3 Options Figure 12.20: ‘Blend’ tool options Overview The available tool options can be accessed by double clicking the Gradient Tool icon. Opacity The Opacity slider sets the transparency level for the gradient. A higher opacity setting results in a more opaque fill and a lower setting results in a more transparent fill. Mode The Mode dropdown list provides a selection of paint application modes. A list of these modes can be found in Section 8.2.
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GNU Image Manipulation Program 178 / 653 Shape The GIMP provides 11 shapes, which can be selected from the drop-down list. Details on each of the shapes are given below. Linear The Lineargradient begins with the foreground color at the starting point of the drawn line and transitions linearly to the background color at the ending point. Bi-Linear The Bi-Linear shape proceeds in both directions from the starting point, for a distance determined by the length of the drawn line.
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GNU Image Manipulation Program 179 / 653 12.3.4 Painting Tools (Pencil, Paintbrush, Airbrush) Figure 12.22: Painting example Three strokes painted with the same round fuzzy brush (outline shown in upper left), using the Pencil (left), Paintbrush (middle), and Airbrush (right). The tools in this group are GIMP’s basic painting tools, and they have enough features in common to be worth discussing together in this section. Features common to all brush tools are described in the Common Features section.
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GNU Image Manipulation Program 180 / 653 Figure 12.23: Dissolve mode example Two brushstrokes made with the Airbrush, using the same fuzzy circular brush. Left: Normal mode. Right: Dissolve mode. Dissolve In this very useful mode, for fuzzy brushes the gray level of the brush determines not the paint density, but rather the probability of applying paint. This gives a nice way of creating rough-looking paintstrokes. Gradient Figure 12.24: Gradient options for painting tools.
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GNU Image Manipulation Program 181 / 653 12.3.5 Pencil Figure 12.25: Pencil tool The Pencil tool is used to draw free hand lines with a hard edge. The pencil and paintbrush are similar tools. The main difference between the two tools is that although both use the same type of brush, the pencil tool will not produce fuzzy edges, even with a very fuzzy brush. It does not even do anti-aliasing.
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GNU Image Manipulation Program 182 / 653 12.3.5.3 Options Figure 12.26: Pencil Tool options Overview The available tool options can be accessed by double clicking the Pencil Tool icon. Opacity; Brush; Pressure Sensibility; Fade Out Note See the Brush Tools Overview for a description of tool options that apply to many or all brush tools. Mode; Color from Gradient Note See the Painting Tools Overview for a description of tool options that apply to many or all painting tools. 12.3.
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GNU Image Manipulation Program 183 / 653 The paintbrush tool paints fuzzy brush strokes. All strokes are rendered using the current brush. 12.3.6.1 Activate Tool • You can call the Paintbrush Tool in the following order, from the image-menu: Tools/ Paint Tools/Paintbrush . • The Tool can also be called by clicking the tool icon: • or by using the P keyboard shortcut. 12.3.6.2 Key modifiers (Defaults) Ctrl , Ctrl This key changes the paintbrush to a Color Picker.
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GNU Image Manipulation Program 184 / 653 Mode; Color from Gradient Note See the Painting Tools Overview for a description of tool options that apply to many or all painting tools. 12.3.7 Eraser Figure 12.29: Eraser tool icon in the Toolbox The Eraser is used to remove areas of color from the current layer or from a selection of this layer.
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GNU Image Manipulation Program 185 / 653 12.3.7.2 Key modifiers See the Section 12.3.1 for a description of key modifiers that have the same effect on all brush tools. • Ctrl: For the Eraser, holding down the Ctrl key puts it into ‘color picker’ mode, so that it selects the color of any pixel it is clicked on. Unlike other brush tools, however, the Eraser sets the background color rather than the foreground color.
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GNU Image Manipulation Program 186 / 653 Note To understand how anti-erasing is possible, you should realize that erasing (or cutting, for that matter) only affects the alpha channel, not the RGB channels that contain the image data. Even if the result is completely transparent, the RGB data is still there, you simply can’t see it. Anti-erasing increases the alpha value so that you can see the RGB data once again.
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GNU Image Manipulation Program 187 / 653 12.3.8.3 Options Figure 12.32: Airbrush options Overview The available tool options can be accessed by double-clicking the airbrush Tool icon. Mode; Use color from gradient Note See the Painting Tools Overview for a description of tool options that apply to many or all painting tools. Rate The Rate slider adjusts the speed of color application that the airbrush paints. A higher setting will produce darker brush strokes in a shorter amount of time.
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GNU Image Manipulation Program 188 / 653 12.3.9 Ink Tool Figure 12.33: Toolbox Pen The Ink tool uses a simulation of an ink pen with a controllable nib to paint solid brush strokes with an antialiased edge. The size, shape and angle of the nib can be set to determine how the strokes will be rendered. 12.3.9.1 Activate Tool You can find the Ink tool in several ways : • In the image-menu through: Tools/ Paint Tools/Ink . • By clicking on the tool icon: in Toolbox. • By using the K keyboard shortcut.
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GNU Image Manipulation Program 189 / 653 Note See the Brush Tools Overview for a description of tool options that apply to many or all brush tools. Overview You can find tool options by double clicking on the ink tool icon. in Toolbox. Opacity Note See the Brush Tools Overview for a description of tool options that apply to many or all brush tools. Note See the Painting Tools Overview for a description of tool options that apply to many or all painting tools.
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GNU Image Manipulation Program 190 / 653 12.3.10 Clone Tool Figure 12.35: Clone tool icon in the Toolbox The Clone tool uses the current brush to copy from an image or pattern. It has many uses: one of the most important is to repair problem areas in digital photos, by "painting over" them with pixel data from other areas. This technique takes a while to learn, but in the hands of a skilled user it is very powerful. Another important use is to draw patterned lines or curves: see Patterns for examples.
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GNU Image Manipulation Program 191 / 653 12.3.10.3 Tool Options Figure 12.36: Tool Options for the Clone tool Opacity; Mode; Brush; Pressure Sensitivity, Fade out, Hard Edges Note See the Brush Tools Overview for a description of tool options that apply to many or all brush tools. Pattern Clicking on the pattern symbol brings up the Patterns dialog, which you can use to select the pattern to paint with. This option is only relevant if you are cloning from a Pattern source.
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GNU Image Manipulation Program 192 / 653 Aligned In this mode, the first click you make when painting sets the offset between the source origin and the cloned result, and all subsequent brushstrokes use the same offset. Thus, you can use as many brushstrokes as you like, and they will all mesh smoothly with one another. If you want to change the offset, you can do this by switching to non-aligned mode, painting one stroke, then switching back to aligned mode.
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GNU Image Manipulation Program 193 / 653 The Convolve tool uses the current brush to locally blur or sharpen your image. Blurring with it can be useful if some element of your image stands out too much, and you would like to soften it. If you want to blur a whole layer, or a large part of one, you will probably be better off using one of the Blur Filters. The direction of a brushstroke has no effect: if you want directional blurring, use the Smudge tool.
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GNU Image Manipulation Program 194 / 653 Opacity; Brush; Pressure Sensitivity; Fade Out; Hard Edges Note See the Brush Tools Overview for a description of tool options that apply to many or all brush tools. Convolve Type Blur mode causes each pixel affected by the brush to be blended with neighboring pixels, thereby increasing the similarity of pixels inside the brushstroke area.
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GNU Image Manipulation Program 195 / 653 12.3.12.3 Options Figure 12.41: ‘Dodge/Burn’ tool options Overview The available tool options for the Dodge or Burn Tool can be accessed by double clicking the Dodge or Burn Tool icon. Opacity; Brush; Pressure sensibility; Fade out; Hard edges Note See the Brush Tools Overview for a description of tool options that apply to many or all brush tools. Type The dodge effect lightens colors. The burn effect darkens colors.
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GNU Image Manipulation Program 196 / 653 12.3.13 Smudge Tool Figure 12.42: Smudge tool The Smudge tool uses the current brush to smudge colors on the active layer or a selection. It takes color in passing and uses it to mix it to the next colors it meets, on a distance you can set. 12.3.13.1 Activate Tool You can find the Smudge tool in various ways : • Through Tools → Paint Tools → Smudge. in the image menu. • By clicking on the tool icon: in Toolbox. • or by pressing the S key on keyboard. 12.3.
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GNU Image Manipulation Program 197 / 653 Overview The available tool options for the Smudge Tool can be accessed by double clicking the Smudge Tool icon. Opacity; Brush; Pressure sensibility; Fade out; Hard edges Note See the Brush Tools Overview for a description of tool options that apply to many or all brush tools. Rate The rate slider sets the strength of the smudge effect. 12.4 Transform Tools 12.4.1 Common Features Figure 12.
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GNU Image Manipulation Program 198 / 653 12.4.1.1 Tool Options Figure 12.45: Common options of transform tools Some options are shared by several transform tools. We will describe them here. More specific options will be described with their tool. Affect GIMP offers you three buttons which let you select which image element the transform tool will work on. Warning Remind that the Affect option persists when you quit the tool. When you ativate the first button whole layer will be transformed.
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GNU Image Manipulation Program 199 / 653 Interpolation The Interpolation drop-down list lets you choose the quality of the transformation. For more information about the different methods that can be employed, see the glossary entry Interpolation. Supersampling See glossary for Supersampling Clip Result After transformation, the image can be bigger. This option will clip the transformated image to the original image size. Preview GIMP lets you select among four Preview possibilities : 1.
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GNU Image Manipulation Program 200 / 653 12.4.2.1 Activate Tool • The Move Tool can be called in the following order, from the image-menu: Tools → Transform Tools → Move • The Tool can also be called by clicking the tool icon: • or by the M keyboard shortcut. • The Move tool is automatically activated when you create a guide. Note Holding down the space bar changes the active tool to Move temporarily. The Move tool remains active as long as the space bar is held down.
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GNU Image Manipulation Program 201 / 653 Affect Note These options are described in Transform tools common options. Keep in mind that your Affect choice persists after quitting the tool. Tool toggle If Affect is on layer : • Pick a layer or guide : On an image with several layers, the mouse pointer turns to a crosshair when it goes over an element belonging to the current layer. Then you can click-and-drag it.
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GNU Image Manipulation Program 202 / 653 12.4.3.1 Activate Tool • The Crop Tool can be called the following way, from the image-menu: Tools → Transform Tools → Crop and Resize. • The Tool can also be called by clicking the tool icon: Tip A different and quicker way to crop selections is using the Image → Crop Image function in the Image menu. 12.4.3.2 Key modifiers (Defaults) Shortcut The Shift-C shortcut will change the active tool to the Crop Tool.
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GNU Image Manipulation Program 203 / 653 Current Layer Only This option will make the crop or resize affect only the active layer. Allow Enlarging This option allows the crop or resize to take place outside the image or layer boundary. Fixed Aspect Ratio With this option, cropping will respect a fixed ratio between Width and Height. C ROP A ND R ESIZE I NFORMATION Origin The Origin selectors allow the manual setting of the top left corner of the cropping region. The units may also be chosen.
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GNU Image Manipulation Program 204 / 653 12.4.4.4 Options Figure 12.51: Rotation tool options Overview The available tool options for the Rotate Tool can be accessed by double clicking the Rotate Tool icon. Affect; Interpolation; Supersampling; Clip Result; Preview Note These options are described in Transform tools common options. Transform Direction The Transform Direction sets which way or direction a layer is rotated. The Traditional mode will rotate the layer as one might expect.
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GNU Image Manipulation Program 205 / 653 Angle Here you can set the rotation angle, from -180 to +180, i.e 360. Center X/Y This option allows you to set the position of the rotation center, represented by a large point in the image. A clickand-drag on this point also allows you to move this center. Default unit of measurement is pixel, but you can change it by using the drop-down list. 12.4.5 Scale Tool Figure 12.53: The Scale tool in Toolbox 12.4.5.
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GNU Image Manipulation Program 206 / 653 12.4.5.4 Options Figure 12.54: Scale tool options Overview The available tool options for the Scale Tool can be accessed by double clicking the Scale Tool icon Toolbox. Affect; Interpolation; Transform Direction; Supersampling; Clip Result; Preview Note These options are described in Transform tools common options. Constraints None: No Height/Width constraint will be imposed to scaling.
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GNU Image Manipulation Program 207 / 653 12.4.5.5 The Scaling Information dialog window Figure 12.55: The Scaling Information dialog window La ventana del diálogo de información de escalado Original Width/Height Here, the width and height of the original object are displayed. Actual Width/Height Here, you can set width and Height you want to give to the object. The default unit of measurement is pixel. You can change it by using the drop-down list.
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GNU Image Manipulation Program 208 / 653 • In the the image-menu through: Tools → Transform Tools → Shear, • By clicking the tool icon: in Toolbox, • or by using the Shift-S key combination. 12.4.6.2 Options Figure 12.57: Shear tool options Overview The available tool options for the Shear Tool can be accessed by double clicking the Shear Tool icon. Affect; Interpolation; Transform Direction; Supersampling; Clip Result; Preview Note These options are described in Transform tools common options. 12.4.
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GNU Image Manipulation Program 209 / 653 12.4.7 Perspective Tool Figure 12.59: Perspective tool The Perspective Tool is used to change the perspective of the active layer content, of the selection boundaries or of a path. When you click on the image, according to the Preview type you have selected, a rectangular frame or a grid pops up around the selection (or around the whole layer if there is no selection), with a handle on each of the four corners.
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GNU Image Manipulation Program 210 / 653 Overview The available tool options for the Perspective Tool can be accessed by double clicking the Perspective Tool icon. Affect; Interpolation; Transform Direction; Supersampling; Clip Result; Preview Note These options are described in Transform tools common options. 12.4.7.3 The Information window for perspective transformation Figure 12.61: The dialog window of the ‘Perspective’ tool Matrix You can get a small knowledge about matrices in the Section 15.7.
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GNU Image Manipulation Program 211 / 653 12.4.8.2 Key modifiers (Defaults) Shortcut The Shift-F key combination will change the active tool to Flip. Ctrl Ctrl lets you change the modes between horizontal and vertical flipping. 12.4.8.3 Options Figure 12.63: ‘Flip Tool’ Options Overview The available tool options for the Flip Tool can be accessed by double clicking the Flip Tool icon. Affect Note These options are described in Transform tools common options.
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GNU Image Manipulation Program 212 / 653 12.5.1.2 Options Figure 12.64: Color Balance options Select range to modify Selecting one of these options will restrict the range of colors which are changed with the sliders or input boxes for Shadows, Midtones and Highlights. Modify selected range’s color levels Sliders and input boxes allow to select colors weights. Initialize range This button sets color levels of the selected range back to zero.
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GNU Image Manipulation Program 213 / 653 12.5.2.2 Options Figure 12.65: Hue-Saturation tool options Select Primary Color to use You can choose, between six, the color to be modified. They are arranged according to the color circle. If you click on the Master button, all colors will be concerned with changes. Modify selected color Changes appear in the small preview close to the selected color button. • Hue : The slider and the input box allow you to select a hue in the color circle (-180, 180).
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GNU Image Manipulation Program 214 / 653 12.5.3.2 Options Figure 12.66: Colorize options Hue The slider and the input box allows you to select a hue in the HSV color circle (0 - 360). Saturation The slider and the input box allows you to select a saturation: 0 through 100. Value The slider and the input box allows you to select a value (luminosity): 0 through 100. Preview The Preview button makes all changes dynamically so that they can be viewed immediately. 12.5.
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GNU Image Manipulation Program 215 / 653 12.5.4.2 Options Figure 12.67: Brightness-Contrast options dialog Brightness This slider sets a negative (to darken) or positive (to brighten) value for the brightness, decreasing or increasing bright tones. Contrast This slider sets a negative (to decrease) or positive (to increase) value for the contrast. Preview The Preview checkbox makes all changes to the brightness and contrast dynamically so that the new level settings can be viewed immediately. 12.5.
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GNU Image Manipulation Program 216 / 653 Threshold range The Threshold tool provides a visual graph, a histogram, of the intensity value of the active layer or selection. You can set the threshold range either using the input boxes or clicking button 1 and dragging on the graph. It allows you to select a part of the image with some intensity from a background with another intensity. Pixels inside the range will be white, and the others will be black.
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GNU Image Manipulation Program 217 / 653 Figure 12.70: The selected layer after threshold fit We got the best outline for our flower. There are several red objects which we must remove. 3. Make sure the image displaying the selected layer is active and copy it to the clipboard with Ctrl-C. 4. Now, make the original image active. Click on the Quick Mask button at the bottom-left corner of the image window: the image gets covered with a red (default) translucent mask.
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GNU Image Manipulation Program 218 / 653 Figure 12.72: The result (a) (b) We used the Zoom to work at a pixel level, the Lasso to remove large unwanted areas, the pencil (to get hard limits), black paint to remove selected areas, white paint to add selected areas, especially for stem. 12.5.6 Levels tool The Level tool provides features similar to the Histogram tool but can also change the intensity range of the active layer or selection. 12.5.6.
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GNU Image Manipulation Program 219 / 653 12.5.6.2 Options Figure 12.73: Level tool options Modify Levels for Channel You can select the specific channel which will be modified by the tool: Value makes changes to the luminosity of all pixels in the image. Color channels allow to change saturation. Alpha channel works on transparency. Initialize channel cancels changes to the selected channel.
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GNU Image Manipulation Program 220 / 653 T OOL O PTIONS DIALOG Histogram Scale These two options have the same action as the logarithmic and Linear buttons in the Levels dialog. Sample Average This slider sets the ‘radius’ of the color-picking area. This area appears as a more or less enlarged square when you maintain the click on a pixel. 12.5.7 Curves Tool 12.5.7.1 Activate Tool You can get to this tools in two ways : • In the image menu through Tools → Color Tools → Curves.
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GNU Image Manipulation Program 221 / 653 Main Editing Area Input and Output Value Domains : The horizontal bar (x-axis) represents input values (they are value levels from 0 to 255). The vertical bar (y-axis) is only a scale for output colors of the selected channel. The control curve is drawn on a grid and goes from bottom left corner to top right corner. Pointer x/y position is permanently displayed in top left part of the grid. If you click on the curve, a Control point is created.
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GNU Image Manipulation Program 222 / 653 Posterize Levels This slider and the input boxes with arrow-heads allow you to set the number of levels (2-256) in each RGB channel that the tool will use to describe the active layer. The total number of colors is the combination of these levels. A level to 3 will give 23 = 8 colors. Preview The Preview checkbox makes all changes dynamically so that they can be viewed straight away. 12.6 Other 12.6.1 Path Tool Figure 12.
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GNU Image Manipulation Program 223 / 653 12.6.1.3 Options Figure 12.77: ‘Path’ tool options Overview The available tool options for the Path Tool can be accessed by double clicking the Path Tool icon. As with other tools, you can delete your changes by Ctrl-Z. Design Mode By default, this tool is in Design mode. You draw the path by clicking successively. You can move control points by clicking on them and dragging them. Between control points are segments.
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GNU Image Manipulation Program 224 / 653 Several functions are available with this mode: Add a new node : if the active node (a small empty circle after clicking on a node) is at the end of the path, the mouse pointer is a ’+’ sign and a new node is created, linked to the previous one by a segment. If the active node is on the path, the pointer is a square and you can create a new component to the path.
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GNU Image Manipulation Program 225 / 653 12.6.2 Color Picker Tool Figure 12.78: Eye dropper The Color Picker Tool is used to select a color on the active layer. By clicking a point on a layer, you can change the active color to that which is located under the pointer. The Sample Merge option lets you grab the color as it is in the image, resulting of the combination of all layers. Figure 12.79: Color Picker Info Window 12.6.2.
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GNU Image Manipulation Program 226 / 653 12.6.2.3 Options Figure 12.80: Color Picker Options Overview The available tool options for the Color Picker can be accessed by double clicking the Color Picker tool icon. Sample Merged The Sample Merged checkbox when enabled will take color information as a composite from all the visible layers. Further information regarding Sample Merge is available in the glossary entry, Sample Merge.
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GNU Image Manipulation Program 227 / 653 12.6.3.1 Activate Tool • You can get to the Magnify Tool from the image-menu through : Tools → Magnify, • or by clicking the tool icon: 12.6.3.2 in Toolbox. Key modifiers (Defaults) Ctrl Holding Ctrl when clicking on a point of your image will change the zoom direction from zooming in to zooming out. 12.6.3.3 Options Figure 12.82: Zoom tool options Overview The available tool options for Magnify can be accessed by double clicking the Magnify tool icon.
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GNU Image Manipulation Program 228 / 653 The Measure Tool is used to gain knowledge about pixel distances in your working image. By clicking and holding the mouse button, you can determine the angle and number of pixels between the point of click and where the mouse pointer is located. The information is displayed on the status bar or can also be displayed in the Info Window. When you pass the mouse pointer over the end point it turns to a move pointer. Then if you click you can resume the measure. 12.6.4.
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GNU Image Manipulation Program 229 / 653 12.6.5 Texttool Figure 12.85: The Text tool in Toolbox The Text tool places text into an image. When you click on an image with this tool the Text Editor dialog is opened where you can type your text, and a text layer is added in the Layer Dialog. In the Text Option dialog, you can change the font, color and size of your text, and justify it, interactively. 12.6.5.
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GNU Image Manipulation Program 230 / 653 Font There are two ways of selecting fonts in the GIMP. The first is from the image Dialogs/Fonts menu. The second is with the Font selector in this tool. Both methods select from the installed X fonts. When you select a font it is interactively applied to your text. Note You can get special characters in the same way as you get them in other text editors: AltGr + key in Linux, Alt + number key pad in Windows.
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GNU Image Manipulation Program 231 / 653 Overview This dialog window is opened when you click on the image with the Text Tool. It’s a still basic text editor that nevertheless allows you to write on several lines. Word wrap is not possible - the text layer lengthens gradually - and you have to press the Enter key to move to the next line. The text you type appears interactively in the image.
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GNU Image Manipulation Program 232 / 653 12.7.2 Indicator Area Figure 12.89: Active tool indicator area This part of the Toolbox shows the currently selected brush, pattern, and gradient. Clicking on any of them brings up a dialog that allows you to change it. 12.7.3 Active image Area Figure 12.90: Current image in the toolbox A thumbnail of the active image can be displayed in this area if the ‘Display Active Image’ option is checked in Preferences/Toolbox.
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GNU Image Manipulation Program 233 / 653 Chapter 13 Dialogs 13.1 Dialog Introduction Dialogs are the most common means of setting options and controls in the GIMP. The most important dialogs are explained in this section. 13.2 Image Structure Related Dialogs 13.2.1 Layers Dialog Figure 13.1: Layer Dialog The Layers dialog is the main interface to edit, modify and manage your layers. You can think of layers as a stack of slides or clothes on your body.
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GNU Image Manipulation Program 234 / 653 Figure 13.2: An image with layers (a) Layers of the image 13.2.1.1 (b) Resulting image: Activate Dialog The Layer dialog can be called in many ways : • from the toolbox-menu: File → Dialog → Layers • from the image-menu: Dialog → Layers • from an other dialog-menu: Add Tab → Layers • from the (default) shortcut: Ctrl-L 13.2.1.2 Using the Layerdialog Overview Every layer appears in the dialog in the form of a thumbnail.
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GNU Image Manipulation Program 235 / 653 Figure 13.3: Layer modes The layer mode determines how the layer interacts with the other layers. From the combo box you can access all the modes provided by GIMP. The layer modes are fully detailed in Section 8.2. Keep transparency Figure 13.4: Keep transparency If you check this option the transparent areas of the layer will be kept, even if you have checked the Fill transparent areas option for the Bucket fill tool. Opacity Figure 13.
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GNU Image Manipulation Program 236 / 653 Tip To move a layer at the bottom of the list, it may first be necessary to add a transparency channel (also called Alpha channel) to the Background layer. To do this, right click on the Background layer and select Add Alpha channel from the menu. Duplicate layer Here you can create a copy of the active layer. Name of new layer is suffixed with a number.
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GNU Image Manipulation Program 237 / 653 • Black (full transparency): the mask is black in the Layer Dialog. So, the layer is fully transparent since painting the mask with black makes layer pixels transparent. Painting with white will remove the mask and make layer pixels visible. • Layer’s alpha channel: the mask is initialized according to the content of layer Alpha channel. If the layer still contains transparency it’s copied in the mask.
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GNU Image Manipulation Program 238 / 653 13.2.2 Channels Dialog Figure 13.9: The Channel dialog The Channels dialog is the main interface to edit, modify and manage your channels. Channels have a double usage. This is why the dialog is divided into two parts: the first part for color channels and the second part for selection masks. Color channels: Color channels apply to the image and not to a specific layer. Basically, three primary colors are necessary to render all the wide range of natural colors.
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GNU Image Manipulation Program 239 / 653 • from the toolbox-menu: File → Dialogs → Channels • from the image-menu: Dialogs → Channels • from another dialog-menu: Add Tab → Channels 13.2.2.2 13.2.2.2.1 Using the Channel dialog Overview The top channels are the color channels and the optional Alpha channel. They are always organized in the same order and they cannot be erased. Selection masks are described below and displayed as a list in the dialog.
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GNU Image Manipulation Program 240 / 653 Tip You can also duplicate a color channel or the Alpha channel. It’s an easy way to keep a copy of them and to use them later as a selection in an image. Channel to selection here you can transform the channel to become a selection. By default the selection derived from a channel replaces any previous active selection. It’s possible to change this by clicking on control keys. • Shift: the selection derived from a channel is added to the previous active selection.
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GNU Image Manipulation Program 241 / 653 13.2.2.3 Selection masks Figure 13.12: A selection composed out of channels. Channels can be used to save and restore your selections. Clicking on the Quick mask button on the Image window automatically creates a new channel called Qmask and saves the displayed active selection to a thumbnail in front of the channel.There are many selection tools in the GIMP like rectangular selection tool or fuzzy selection for continuous selections.
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GNU Image Manipulation Program 242 / 653 13.2.2.4 Quick Mask Figure 13.13: Dialog Quick Mask A Quick Mask is a Selection Mask intended to be used temporarily to paint a selection. Temporarily means that, unlike a normal selection mask, it will not be saved in the list after its transformation to selection. The selection tools sometimes show their limits when they have to be used for doing complex drawing selection, as progressive.
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GNU Image Manipulation Program 243 / 653 Description v 1 v 2 v 3 Screenshot of the image window with activated QuickMask. The QuickMask is filled with a gradient from black (left) to white (right). The QuickMask is now disabled and a selection is initialised from the QuickMask, which was filled by a gradient before. You see the selection borders in the middle of the image. A stroke is now added during the enabled selection.
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GNU Image Manipulation Program 244 / 653 13.2.3.1 Dialog call • From the Toolbox menu: File → Dialogs → Paths. • From the Toolbox menu: File → Dialogs → Create New Dock → Layers, Channels, and Paths. This gives you a dock containing three dialogs, with the Paths dialog one of them. • From an image menu: Dialogs → Paths. • From the Tab menu in any dockable dialog: Add Tab → Paths. 13.2.3.2 Using the Paths dialog Each path belongs to one image: paths are components of images just like layers.
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GNU Image Manipulation Program 245 / 653 Duplicate Path See Duplicate Path. Path to Selection Converts the path into a selection; see Path to Selection for a full explanation. You can use modifier keys to set the way the new selection interacts with the existing selection: Modifiers: Modifiers: Modifiers: Modifiers: None, Action: Replace existing selection Shift , Action: Add to selection Ctrl , Action: Subtract from selection Shift-Ctrl , Action: Intersect with selection.
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GNU Image Manipulation Program 246 / 653 Duplicate Path "Duplicate Path" creates a copy of the active path, assigns it a unique name, adds it to the list in the Paths dialog, and makes it the active path for the image. The copy will be visible only if the original path was visible. Note Note that copying a visible path will make the path "disappear" from the image display: this happens because paths are drawn in XOR mode, which has the curious property that drawing an item twice "undraws" it.
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GNU Image Manipulation Program 247 / 653 Paste Path Paste Path creates a new path from the contents of the Path Clipboard, adds it to the list in the Paths dialog, and makes it the active path for the image. If no path has previously been copied into the clipboard, the menu entry will be insensitive. Import Path "Import Path" creates a new path from an SVG file: it pops up a file chooser dialog that allows you to navigate to the file.
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GNU Image Manipulation Program 248 / 653 not be able to find exactly the right colors in the colormap, so it will approximate them by using the nearest color available. the colormap is too limited or poorly chosen, this can easily produce very poor image quality. 1 If The Colormap dialog allows you to alter the colormap for an image, either by creating new entries, or by changing the colors for the existing entries.
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GNU Image Manipulation Program 249 / 653 13.2.5 Histogram dialog Figure 13.17: The Histogram dialog The Histogram dialog shows you information about the statistical distribution of color values in the image that is currently active. This information is often useful when you are trying to color balance an image. However, the Histogram dialog is purely informational: nothing you do with it will cause any change to the image. If you want to perform a histogram-based color correction, use the Levels tool.
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GNU Image Manipulation Program 250 / 653 This allows you to select which channel to use. The possibilities depend on the layer type of the active layer. Here are the entries you might see, and what they mean: Value For RGB and Grayscale images, this shows the distribution of brightness values across the layer. For a grayscale image, these are read directly from the image data. For an RGB image, they are taken from the Value pseudochannel.
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GNU Image Manipulation Program 251 / 653 Figure 13.21: Dialog aspect after range fixing. You can restrict the analysis, for the statistics shown at the bottom of the dialog, to a limited range of values if you wish. You can set the range in one of three ways: • Click and drag the pointer across the histogram display area, from the lowest level to the highest level of the range you want. • Click and drag the black or white triangles on the slider below the histogram.
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GNU Image Manipulation Program 252 / 653 • from the toolbox-menu: File/ Dialogs/ Navigation • from the image-menu: Dialogs/ Navigation • from the image-menu: View/ Navigation window, the Shift+Ctrl+N will call the Navigation Window. • from another dialog-menu: Add Tab/ Navigation You can access more quickly to it (but without the zoom functions) by clicking on the of the image window. 13.2.6.
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GNU Image Manipulation Program 253 / 653 13.2.7.1 Activate the dialog The Undo History dialog is a dockable dialog; see the section on Dialogs and Docking for help on manipulating it. It can be activated in several ways: • From the Toolbox menu: File → Dialogs → Undo History. • From the Toolbox menu: File → Dialogs → Create New Dock → Layers, Channels, and Paths. This gives you a dock containing four dialogs, with the Undo History dialog one of them. • From an image menu: Edit → Undo History.
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GNU Image Manipulation Program 254 / 653 13.3 Image Content Related Dialogs 13.3.1 Colors Dialog Figure 13.24: Colors dialog The Channel dialog lets you manage and pick up new colors. It is divided into five separate parts: GIMP, CMYK, Triangle, Watercolor and Scales. You can use the eyedropper, which is the last button of the dialog, to pick up a color anywhere on your screen. 13.3.1.
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GNU Image Manipulation Program 255 / 653 Scales This Scales exists only in the color selector you get from the file menu of the Tool-Box or from the Dialogs menu in the image menu bar. This selector displays a global view of R, G, B channels and H, S, V values, placed in sliders. Color picker This color picker exists only in the color selector you get from the file menu of the Tool-Box or from the Dialogs menu in the image menu bar.
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GNU Image Manipulation Program 256 / 653 • From the Toolbox, by clicking on the brush symbol in the Brush/Pattern/Gradient area. • From an image menu: Dialogs → Brushes. • From the Tab menu in any dockable dialog: Add Tab → Brushes.
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GNU Image Manipulation Program 257 / 653 13.3.2.2.2 Buttons at the bottom At the bottom of the dialog you find a couple of buttons: Spacing Below the grid appears a scale entry for ‘Spacing’, which is the distance between consecutive brush marks when you trace out a brushstroke with the pointer. Edit Brush This activates the Brush Editor. Pressing the button will open the Editor for any brush.
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GNU Image Manipulation Program 258 / 653 Shape A circle, a square and a diamond are available. You will modify them by using the following options: Radius Distance between brush center and edge, in the width direction. A square with a 10 pixels radius will have a 20 pixels side. A diamond with a 5 pixels radius will have a 10 pixels width. Spikes This parameter is useful only for square and diamond. With a square, increasing spikes results in a polygon. With a diamond, you get a star.
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GNU Image Manipulation Program 259 / 653 • From an image menu: Dialogs → Patterns. • From the Tab menu in any dockable dialog: Add Tab → Patterns. • From the Tool Options dialog of the Clone tool and the Bucket Fill tool, by clicking on the pattern source button, you get a popup with similar functionality that permits you to quickly choose a pattern from the list; if you clic on the Bucket Fill button present on the right bottom of the popup, you open the real pattern dialog.
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GNU Image Manipulation Program 260 / 653 If you double-click on the name of a pattern, you will be able to edit the name. Note that you are only allowed to rename patterns that you have added yourself, not the ones that are supplied with GIMP. If you edit a name that you don’t have permission to change, as soon as you hit return or move to a different control, the name will revert back to its previous value. Everything else in the List view works the same way as it does in the Grid view.
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GNU Image Manipulation Program 261 / 653 13.3.4.2 Using the Gradients dialog The most basic, and most commonly used, operation with the dialog is simply to click on one of the gradients in the scrollable list, in order to make it GIMP’s current gradient, which will then be used by any operation that involves a gradient. If you double-click on a gradient, you open the Gradient Editor where you will be able to edit its name.
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GNU Image Manipulation Program 262 / 653 13.3.4.3 Gradient Editor Figure 13.31: The gradient editor The Gradient Editor allows you to edit the colors in a gradient. It can only be used on gradients you have created yourself (or on a copy of a system gradient), not on system gradients that come pre-installed with GIMP. This is a sophisticated tool that may take a bit of effort to understand.
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GNU Image Manipulation Program 263 / 653 shift-clicking on them. The selected range always consists of a set of consecutive segments, so if you skip over any when shift-clicking, they will be included automatically. If ‘Instant update’ is checked, the display is updated immediately after any slider movement; if it is unchecked, updates only occur when you release the mouse button. You can move sliders, segments and selections. If you simply click-n-drag a slider, you only move the corresponding transition.
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GNU Image Manipulation Program 264 / 653 Figure 13.33: The "Load Color From" submenu Load Left [Right] Color From These options give you a number of alternative ways of assigning colors to the endpoints. From the submenu you can choose (assuming we’re dealing with the left endpoint): Left Neighbor’s Right Endpoint This choice will cause the color of the right endpoint of the segment neighboring on the left to be assigned to the left endpoint of the selected range.
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GNU Image Manipulation Program 265 / 653 Flip Segment/Selection This option does a right-to-left flip of the selected range (segment or selection), flipping all colors and endpoint locations. Replicate Segment/Selection This option splits the selected range (segment or selection) into two parts, each of which is a perfect compressed copy of the original range.
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GNU Image Manipulation Program 266 / 653 Note The Palettes dialog is not the same thing as the Index Palette dialog, which is used to manipulate the colormaps of indexed images. 13.3.5.1 Activate Dialog The Palettes dialog is a dockable dialog; see the section on Dialogs and Docking for help on manipulating it. It can be activated in several ways: • From the Toolbox menu: File → Dialogs → Palettes. • From an image menu: Dialogs → Palettes. • From the Tab menu in any dockable dialog: Add Tab → Palettes.
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GNU Image Manipulation Program 267 / 653 Edit Palette This button brings up the Palette Editor. New Palette See New Palette. Duplicate Palette See Duplicate Palette. Delete Palette See Delete Palette. Refresh Palettes See Refresh Palettes. 13.3.5.3 Palettes Menu Figure 13.38: The Palettes Menu The Palettes Menu can be accessed by right-clicking in the Palettes dialog, or by choosing the top item from the dialog Tab menu.
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GNU Image Manipulation Program 268 / 653 Select Source You can import a palette either from any of GIMP’s gradients (choosing one from the adjoining menu), or from any of the currently open images (chosen from the adjoining menu). In GIMP 2.2, you can also import a RIFF palette file (with extension .pal), of the type used by several Microsoft Windows applications. Palette name You can give a name to the new palette here.
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GNU Image Manipulation Program 269 / 653 13.3.5.4.2 Using the Palette Editor If you click on a color box in the palette display, GIMP’s foreground color will be set to the selected color: you can see this in the Color Area of the Toolbox. If you hold down the Ctrl key while clicking, GIMP’s background color will be set to the selected color. Double-clicking on a color not only sets the foreground, it also brings up a color editor that allows you to modify the selected palette entry.
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GNU Image Manipulation Program 270 / 653 New Color from FG; New Color from BG These commands each create a new palette entry, using either GIMP’s current foreground color (as shown in the Color Area of the Toolbox), or the current background color. Delete Color "Delete Color" removes the selected color entry from the palette. If the palette is one that you are not allowed to edit, then the menu entry will be insensitive. Zoom Out "Zoom Out" reduces the vertical scale of the entries in the palette display.
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GNU Image Manipulation Program 271 / 653 Grid/List modes Figure 13.43: The Fonts dialog (a) Dialog in Grid View (b) Dialog in List View In the Tab menu for the Fonts dialog, you can choose between View as Grid and View as List. In Grid mode, the fonts are laid out in a rectangular array. In List mode, they are lined up vertically, with each row showing an example of the appearance of the font ("Aa"), followed by the name of the font.
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GNU Image Manipulation Program 272 / 653 pops up asking you to name a buffer to store the data in. There is no hard limit on the number of named buffers you can create, although, of course, each one consumes a share of memory. The Buffers dialog shows you the contents of all existing named buffers, and allows you to operate on them in several ways. It also shows you, at the top, the contents of the Global Buffer, but this is merely a display: you can’t do anything with it.
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GNU Image Manipulation Program 273 / 653 13.4.1.2.2 Buttons at the bottom At the bottom of the dialog you find a couple of buttons: Paste Buffer This command pastes the contents of the selected buffer into the active image, as a floating selection. The only difference between this and the ordinary Paste command is that it uses the selected buffer rather than the global clipboard buffer.
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GNU Image Manipulation Program 274 / 653 Grid/List modes, Previews size As in all dialogs with thumbnails, the Tab menu gives you the possibility of adapting thumbnail display to your liking. See Docking Raise this image’s display The selected image appears at the foreground of your screen. Create a new display for this image Duplicates the image window (not the image) of the selected image. Delete This button is not working. 13.4.3 Document History Dialog Figure 13.
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GNU Image Manipulation Program 275 / 653 13.4.4 Templates Dialog Figure 13.48: The Templates dialog Templates are templates for an image format to be created. GIMP offers you a lot of templates and you can create your owns. When you create a New image, you can access to the list of existing templates but you can’t manage them. The ‘Templates’ dialog allows you to manage all these templates. 13.4.4.
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GNU Image Manipulation Program 276 / 653 13.4.4.3 Edit Template Figure 13.49: The Edit Template dialog The dialog allows you to set the specifications of the selected template. You can access to this editor by clicking on the Edit Template button in the Templates dialog. O PTIONS Name In this text box, you can modify the displayed template name. Icon By clicking on this icon, you open a list of icons. You can choose one of them to illustrate the selected template name.
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GNU Image Manipulation Program 277 / 653 • Foreground color, as shown in the Main Toolbox. • Background color, as shown in the Main Toolbox. • White, the more often used. • Transparent. If this option is chosen, then the Background layer in the new image will be created with an alpha channel; otherwise not. Comment You can write a descriptive comment here. The text will be attached to the image as a ‘parasite’, and will be saved along with the image by some file formats (but not all of them). 13.
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GNU Image Manipulation Program 278 / 653 13.5.1.2 Using the Tools dialog The most basic thing you can do is to select a tool by clicking on its icon: this has the same effect as clicking on an icon in the Toolbox. You can do this in either List or Grid mode: the other functions of the dialog are available only in List mode.
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GNU Image Manipulation Program 279 / 653 13.5.2.2 New Image Preferences Figure 13.52: New Image Preferences This tab lets you customize the default settings for the New Image dialog. See the New Image Dialog section for an explanation of what each of the values means.
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GNU Image Manipulation Program 280 / 653 13.5.2.3 Default Image Grid Figure 13.53: Default Grid Preferences This page lets you customize the default properties of GIMP’s grid, which can be toggled on or off using View → Show Grid from the image menu. The settings here match those in the Configure Image Grid dialog, which can be used to reconfigure the grid for an existing image, by choosing Image → Configure Grid from the image menu.
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GNU Image Manipulation Program 281 / 653 13.5.2.4 Interface Figure 13.54: Assorted Interface Preferences This page lets you customize layer/channel previews and keyboard shortcuts. O PTIONS Previews By default, GIMP shows miniature previews of the contents of layers and channels in several places, including the Layers dialog. If for some reason you would prefer to disable these, you can do it by unchecking ‘Enable layer and channel previews’.
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GNU Image Manipulation Program 282 / 653 13.5.2.5 Theme Figure 13.55: Theme Preference This page lets you select a theme, which determines many aspects of the appearance of the GIMP user interface, including the set of icons used, their sizes, fonts, spacing allowed in dialogs, etc. Two themes are supplied with GIMP: Default, which is probably best for most people, and Small, which may be preferable for those with small or low-resolution monitors.
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GNU Image Manipulation Program 283 / 653 13.5.2.6 Help System Figure 13.56: Help System Preferences (Linux Screenshot) This page lets you customize the behaviour of the GIMP help system. 13.5.2.6.1 Options G ENERAL Show tool tips Tool tips are small text bubbles that appear when the pointer hovers for a moment over some element of the interface, such as a button or icon. Sometimes they explain what the element does; sometimes they give you hints about non-obvious ways to use it.
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GNU Image Manipulation Program 284 / 653 Note Note that the help browser is not available on all platforms. If it is missing, the web-browser will be used to allow access to the help pages. W EB B ROWSER Web browser to use If you selected ‘GIMP help browser’ for the Help browser, this option has no effect. If you selected ‘Web browser’, you can decide here which browser to use, and how to invoke it, by entering the command that will be used to run the browser.
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GNU Image Manipulation Program 285 / 653 Default threshold The "magic wand" tool creates selections that consist of contiguous regions, i. e., regions that are not divided by swaths of open space. This option determines how near each other two pixels need to be in order to be considered contiguous. S CALING Default interpolation When you scale something, each pixel in the result is calculated by interpolating several pixels in the source.
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GNU Image Manipulation Program 286 / 653 13.5.2.8.1 Options Figure 13.59: Default Toolbox appearance This page lets you customize the appearance of the Toolbox, by deciding whether the three "context information" areas should be shown at the bottom. A PPEARANCE Show foreground and background color Controls whether the color area on the left (3) appears in the Toolbox.
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GNU Image Manipulation Program 287 / 653 13.5.2.9.1 Options G ENERAL Use "Dot for dot" by default Using "Dot for dot" means that at 1:1 zoom, each pixel is the image is scaled to one pixel on the display. If "Dot for dot" is not used, then the displayed image size is determined by the X and Y resolution of the image. See the Scale Image section for more information.
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GNU Image Manipulation Program 288 / 653 13.5.2.10 Image Window Appearance Figure 13.61: Image Window Appearance Defaults This page lets you customize the default appearance of image windows, for normal mode and for fullscreen mode. All of the settings here can be altered on an image-specific basis using entries in the View menu. See the Image Window section for information on the meaning of the entries. The only parts that may need further explanation are the ones related to padding.
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GNU Image Manipulation Program 289 / 653 13.5.2.11 Image Window Title and Statusbar Figure 13.62: Image Window Title and Statusbar formats This page lets you customize the text that appears in two places: the title bar of an image, and the status bar. The title bar should appear above the image; however this depends on cooperation from the window manager, so it is not guaranteed to work in all cases. The statusbar appears underneath the image, on the right side.
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GNU Image Manipulation Program 290 / 653 Variable: %u, Meaning: Unit symbol (eg. px for Pixel) Variable: %U, Meaning: Unit abbreviation Variable: %%, Meaning: A literal "%" symbol 13.5.2.12 Display Figure 13.63: Display Preferences This page lets you customize the way transparent parts of an image are represented, and lets you recalibrate the resolution of your monitor. 13.5.2.12.
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GNU Image Manipulation Program 291 / 653 Figure 13.64: The Calibration dialog Monitor Resolution Monitor Resolution is the ratio of pixels, horizontally and vertically, to inches. You have three ways to proceed here: • Get Resolution from windowing system. (easiest, probably inaccurate). • Set Manually • Push the Calibrate Button. The Calibrate Dialog My monitor was impressively off when I tried the Calibrate Dialog. The "Calibrate Game" is fun to play. You will need a soft ruler. 13.5.2.
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GNU Image Manipulation Program 292 / 653 E XTENDED I NPUT D EVICES Configure Extended Input Devices This large button allows you to set the devices associated with your computer: tablet, MIDI keyboard... If you have a tablet, you will see a dialog like this: Figure 13.66: Preferences for a tablet Save input device settings on exit When you check this box, GIMP remembers the tool, color, pattern and brush you were using the last time you quitted. Save input device settings now Self explanatory.
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GNU Image Manipulation Program 293 / 653 This dialog has two tabs that allow you to assign actions to the mouse wheel and to keyboard keys: M AIN M OUSE W HEEL General • Dump events from this controller: this option must be checked if you want a print on the stdout of the events generated by the enabled controllers. If you want to see those event you should start GIMP from a terminal or making it to print the stdout to file by the shell redirection. The main use of this option is for debug.
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GNU Image Manipulation Program 294 / 653 Figure 13.69: Main Keyboard Note You will find an example of these notions in Creating a variable size brush. 13.5.2.15 Window Managment Figure 13.
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GNU Image Manipulation Program 295 / 653 This page lets you customize the way windows are handled in GIMP. You should note that GIMP does not manipulate windows directly, instead it sends requests to the window manager (i. e., to Windows if you are running in Windows; to Metacity if you are running in a standard Gnome setup in Linux; etc). Because there are many window managers, and not all of them are well behaved, it cannot be guaranteed that the functions described here will actually work as described.
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GNU Image Manipulation Program 296 / 653 13.5.2.16 Environment Figure 13.71: Environment Preferences This page lets you customize the amount of system memory allocated for various purposes. It also allows you to disable the confirmation dialogs that appear when you close unsaved images, and to set the size of thumbnail files that GIMP produces. 13.5.2.16.
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GNU Image Manipulation Program 297 / 653 Maximum filesize for thumbnailing If an image file is larger than the specified maximum size, GIMP will not generate a thumbnail for it. This options allows you to prevent thumbnailing of extremely large image files from slowing GIMP to a crawl. S AVING I MAGES Confirm closing of unsaved images Closing an image is not undoable, so by default GIMP asks you to confirm that you really want to do it, whenever it would lead to a loss of unsaved changes.
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GNU Image Manipulation Program 298 / 653 13.5.2.18 Data Folders Figure 13.73: Preferences: Brush Folders GIMP uses several types of resources – such as brushes, patterns, gradients, etc. – for which a basic set are supplied by GIMP when it is installed, and others can be created or downloaded by the user.
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GNU Image Manipulation Program 299 / 653 13.5.3 Device Status Dialog Figure 13.74: The device Status Dialog This window gathers together the current options of Toolbox, for each of your input devices: the mouse (named ‘Core pointer’) or either the tablet, if you have one. These options are represented by icons: foreground and background colors, brush, pattern and gradient.
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GNU Image Manipulation Program 300 / 653 13.5.4.2 The ‘Error Console’ Dialog Figure 13.75: ‘Error Console’ Dialog window Clear errors This button lets you delete all errors in the log. Warning You can’t ‘undo’ this action. Save all errors This button lets you save the whole log. You can also select a part of the log (by click-and-dragging the mouse pointer or by using the Shift-Arrow keys key combination) and save only this selected part by pressing the Shift key.
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GNU Image Manipulation Program 301 / 653 Portable Network Graphics (PNG) Figure 13.77: Export PNG File Dialog The PNG format, a lossless format, supports transparency but doesn’t support animation. So, you only can Flatten image, i.e merge layers into a single one, according to the mode you have selected for the image. JPEG File Interchange Format (JFIF, JPEG) Figure 13.78: Export JPG File Dialog The JPEG format, a compression format with loss, doesn’t support animation nor transparency.
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GNU Image Manipulation Program 302 / 653 Figure 13.79: Export MNG File Dialog Diálogo exportar como MNG The MNG format, an animation format, supports 256 transparency levels, which, unfortunately, are not recognized by Internet Explorer 6. The dialog offers two options. Select Save as animation. The other option, Flatten Image has no sense here. and, for that matter, an image which is saved so is not recognized by GIMP. Graphics Interchange Format (GIF) Figure 13.
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GNU Image Manipulation Program 303 / 653 Chapter 14 Menus 14.1 Introduction to Menus Figure 14.1: The Toolbox Menu There are many places in GIMP where you can find menus. The aim of this chapter is to explain all the commands that are accessible from the menus in the Toolbox and Image windows. All the context menus and the menu entries for the other dialogs are described elsewhere in the chapters that describe the dialogs themselves. 14.1.
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GNU Image Manipulation Program 304 / 653 14.1.2 Detachable Submenus There is an interesting property associated with some of the menus in GIMP. These are any of the menus from the Toolbox menubar and any of their submenus, as well as the Image context menu you get by right-clicking on the image window and any of its submenus. (You can tell that a menu item leads to a submenu because there is an icon next to it.
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GNU Image Manipulation Program 305 / 653 • Section 14.5.5 • Section 14.2.2 • Section 14.5.14 Note Besides the commands described here, you may also find other entries in the menu. They are not part of GIMP itself, but have been added by extensions (plug-ins). You can find information about the functionality of a Plugin by referring to its documentation. 14.2.2 Acquire Figure 14.
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GNU Image Manipulation Program 306 / 653 The Screen Shot command opens a dialog which has four options for grabbing the object: Single Window a Single Window: You can select the window you want to capture. Select Window After ... Seconds Delay Select Window After ... Seconds Delay: If you enter 0 seconds in the text box, the window is captured as soon as you click on it. If you enter a delay, you have time to modify the window before it is captured.
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GNU Image Manipulation Program 307 / 653 14.2.4 The Dialogs Sub-Menu Figure 14.7: The Dialogs submenu of the Toolbox File menu The Dialogs submenu of the Toolbox’s File menu contains a list of available dialogs that you can use while you are editing an image -- patterns, palettes, brushes, etc. You can open and close dialogs as needed, or, if you want them to stay around, you can dock them. Dialogs are described in detail in Chapter 13 14.2.4.
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GNU Image Manipulation Program 308 / 653 Note Besides the commands described here, you may also find other entries in the menu. They are not part of GIMP itself, but have been added by extensions (plug-ins). You can find information about the functionality of a Plugin by referring to its documentation. 14.3.2 The Module Manager With the Module Manager command, you can show the various extension modules which are available and control which of them should be loaded.
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GNU Image Manipulation Program 309 / 653 14.3.3.2 Description of the ‘Unit Editor’ dialog window Figure 14.10: The ‘Unit Editor’ dialog window The figure above shows the ‘Unit Editor’ dialog window. The list shows the units of measurement which are currently defined. You can click on the New button or the Duplicate button to create a new measurement unit, as described below. D ESCRIPTION OF THE LIST ELEMENTS • Saved: If this column is checked, a unit definition will be saved when GIMP exits.
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GNU Image Manipulation Program 310 / 653 14.3.3.3 Defining New Units Figure 14.11: The ‘New Unit’ dialog You can display the dialog shown above by clicking on either the New button or the Duplicate button on the Unit Editor dialog. The input fields on the dialog are described above. If you click on the New button, the dialog looks as shown.
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GNU Image Manipulation Program 311 / 653 14.3.4.2 Description of the ‘Plug-In Browser’ dialog window Figure 14.12: The list view of the ‘Plug-In Browser’ dialog window The figure above shows the list view of the Plug-In Browser. You can click on the name of a plug-in in the scrolled window to display more information about it. Select the List View by clicking on the tab at the top of the dialog.
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GNU Image Manipulation Program 312 / 653 Note Not everything in these huge dialog windows is visible at the same time. Use the scroll bars to view their content. 14.3.5 The Procedure Browser The Procedure Browser command displays the procedures in the PDB, the Procedure Database. These procedures are functions which are called by the scripts or plug-ins. You can find a more detailed description of the PDB in the glossary. The browser is most useful for advanced users who write scripts or plug-ins. 14.3.
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GNU Image Manipulation Program 313 / 653 14.3.6 The ‘Script-Fu’ Submenu Figure 14.15: The ‘Script-Fu’ submenu of the Xtns menu The Script-Fu command displays a submenu which contains a large number of Script-Fu scripts and options, including the ScriptFu console. Script-Fu is a language for writing scripts, which allow you to run a series of GIMP commands automatically. These scripts create a new image : they are stand-alone scripts. 14.3.6.
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GNU Image Manipulation Program 314 / 653 Tip If the help does not seem to work, please verify that the ‘GIMP Users Manual’ is installed on your system. You can find the most recent help online [GIMP-DOCS]. 14.4.2.1 Activating the Command • You can access this command from the toolbox menubar through Help → Help, • or by using the keyboard shortcut F1. 14.4.3 Context Help The Context Help command makes the mouse pointer context-sensitive and changes its shape to a ‘?’.
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GNU Image Manipulation Program 315 / 653 14.4.5.1 Activating the About Command • You can access this command in the toolbox menu through Help → About 14.4.5.2 Description of the dialog window Figure 14.18: The ‘About’ dialog window 14.4.6 GIMP online Figure 14.19: The ‘GIMP online’ submenu of the Help menu The GIMP online command displays a submenu which lists several helpful web sites that have to do with various aspects of GIMP.
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GNU Image Manipulation Program 316 / 653 14.5 The ‘File’ Menu 14.5.1 File menu Figure 14.20: The File menu of the image window Figure 14.21: The File menu of the Toolbox There is a File menu on both the Toolbox window and the image window. Only some of the menu items in these two menus are the same. Note Besides the commands described here, you may also find other entries in the menu. They are not part of GIMP itself, but have been added by extensions (plug-ins).
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GNU Image Manipulation Program 317 / 653 14.5.2.2 Basic Options Figure 14.22: The ‘New Image’ dialog Template Figure 14.23: The ‘Create a New Image’ dialog Rather than entering all the values by hand, you can select some predefined values for your image from a menu of templates, which represent image types that are somewhat commonly useful. The templates set values for the size, resolution, comments, etc.
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GNU Image Manipulation Program 318 / 653 Note Keep in mind that every pixel of an image is stored in memory. If you create large files with a high pixel density, GIMP will need a lot of time and memory for every function you apply to the image. Portrait/Landscape buttons There are two buttons which toggle between Portrait and Landscape mode. What they actually do is to exchange the values for Width and Height. (If the Width and Height are the same, these buttons are not activated.
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GNU Image Manipulation Program 319 / 653 Figure 14.25: Colorspace menu You can create the new image as either an RGB image or a grayscale image. RGB color: The image is created in the Red, Green, Blue color system, which is the one used by your monitor or your television screen. Grayscale: The image is created in black and white, with various shades of gray. Aside from your artistic interests, this type of image may be necessary for some plug-ins.
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GNU Image Manipulation Program 320 / 653 14.5.3.2 File browsing Figure 14.27: Open Dialog v 1 v 2 The left panel is divided into two parts. The upper part lists your main directories and your storage devices; you cannot modify this list. The lower part lists your bookmarks; you can add or remove bookmarks. To add a bookmark, select a directory or a file in the middle panel and click on the Add button at the bottom of the left panel.
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GNU Image Manipulation Program 321 / 653 14.5.4 Open Location The Open Location dialog lets you load an image from a network location, specified by a URI, in any of the formats that GIMP supports, or from a path to your hard disk or any drive. The default directory name is /home// on Linux and C:\Documents and Settings\\My Documents\My Images\ on Windows, which is used as the base of the relative address. You can also enter an absolute path.
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GNU Image Manipulation Program 322 / 653 14.5.7 Save The Save command saves your image to disk. If you have already saved the image, the previous image file is overwritten with the current version. If you have not already saved the image, the Save command does the same thing as the Save As command: GIMP opens the File Save dialog, so that you can choose the data format, the path and the filename of the new image file.
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GNU Image Manipulation Program 323 / 653 14.5.8.3 The ‘Save’ Dialog with a Browser Figure 14.30: The ‘Save’ Dialog (Browser) v 1 v 2 The left panel is divided into two parts. The upper part lists your main directories and your storage devices; you cannot modify this list. The lower part lists your bookmarks; you can add or remove bookmarks. To add a bookmark, select a directory or a file in the middle panel and click on the Add button at the bottom of the left panel.
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GNU Image Manipulation Program 324 / 653 v 8 v 9 v 6 If you want to save the image into a folder that doesn’t yet exist, you can create it by clicking on Create Folder and following the instructions. This button shows All Files by default. This means that all file types will be displayed in the middle panel, even if they are not images. You can filter the list for a particular file type. At Determine File Type, you have to select the file format for saving the file.
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GNU Image Manipulation Program 325 / 653 14.5.12 Print The Print command is not really part of GIMP. It simply calls the printing interface of your operating system to set the printer options. See Print your photos. 14.5.12.1 Activating the Command You can access this command from the image menubar through File → Print. 14.5.13 Close The Close command closes the image and removes its window. Closing an image is not undoable: once it is closed, everything is gone, including the undo history.
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GNU Image Manipulation Program 326 / 653 14.6 The ‘Edit’ Menu 14.6.1 ‘Edit’ Menu Entries Figure 14.31: Contents of the Edit Menu In this section, you will find help for commands in the Edit menu item. Note Besides the commands described here, you may also find other entries in the menu. They are not part of GIMP itself, but have been added by extensions (plug-ins). You can find information about the functionality of a Plugin by referring to its documentation. 14.6.
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GNU Image Manipulation Program 327 / 653 14.6.3 Redo The Redo command reverses the effects of the Undo command. Each ‘Undo’ action can be reversed by a single ‘Redo’ action. You can alternate ‘Undo’ and ‘Redo’ as many times as you like. Note that you can only ‘Redo’ an operation if the last action you did was an ‘Undo’. If you perform any operation on the image after Undoing something, then the former Redo steps are lost, and there is no way to recover them. See the Undoing section for more information.
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GNU Image Manipulation Program 328 / 653 14.6.6.1 Activating the Command • You can access this command from the image memubar through Edit → Copy, • or by using the keyboard shortcut Ctrl-C. 14.6.7 Copy Visible The Copy Visible command is similar to the Copy command. However, it does not just copy the contents of the current layer; it copies the contents of the visible layers (or the selection of the visible layers), that is, the ones that are marked with an ‘eye’.
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GNU Image Manipulation Program 329 / 653 14.6.10 Paste as New The Paste As New command creates a new image and pastes the image data from the Clipboard into it. If the data is not rectangular or square in shape, any regions that do not extend to the edge of the canvas are left transparent (an Alpha channel is automatically created). Of course, you have to Copy your selection before you use this command, so that you get an image with the same dimensions as the selection. 14.6.10.
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GNU Image Manipulation Program 330 / 653 14.6.11.4 Paste Named The Paste Named command simply brings up the Buffers dialog. By selecting one of the listed buffers, and pressing one of the buttons at the bottom, you can either Paste Buffer, Paste Buffer Into, or Paste Buffer as New. ACTIVATING THE C OMMAND • You can access this command from the image menubar through Edit → Buffer → Paste • or by using the keyboard shortcut Shift-Ctrl-V. 14.6.
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GNU Image Manipulation Program 331 / 653 14.6.14 Fill with BG Color The Fill with BG Color command fills the active layer selection with the solid color shown in the Background part of the Color Area of the Toolbox. (The color is also shown to the left of the menu entry.) If some areas of the image are only partially selected (for example, as a result of feathering the selection), they are filled in proportion to how much they are selected.
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GNU Image Manipulation Program 332 / 653 14.6.16.1 Activating the Command • You can access this command from the image menubar through Edit → Stroke Selection. • You can also access it through the Selection Editor. 14.6.16.2 The ‘Stroke Selection’ dialog Note The options for stroking selections and for stroking paths are the same. You can find the documentation about the options in the dialog box in the Stroke Path section. 14.6.17 Stroke Path The Stroke Path command strokes a path in the image.
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GNU Image Manipulation Program 333 / 653 The Choose Stroke Style dialog box allows you to choose between stroking the path with the options you specify or stroking it with a paint tool. If you stroke the path with a paint tool, the current paint tool options are used to draw the stroke. Stroke line The stroke is drawn with the current foreground color, set in the Toolbox.
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GNU Image Manipulation Program 334 / 653 14.7 The ‘Select’ Menu 14.7.1 Introduction to the ‘Select’ Menu Figure 14.35: The Contents of the ‘Select’ menu This section explains the commands on the Select menu of the image menubar. Note Besides the commands described here, you may also find other entries in the menu. They are not part of GIMP itself, but have been added by extensions (plug-ins). You can find information about the functionality of a Plugin by referring to its documentation. 14.7.
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GNU Image Manipulation Program 335 / 653 14.7.4 Invert The Invert command inverts the selection in the current image. That means that all of the image contents which were previously outside of the selection are now inside it, and vice versa. If there was no selection before, the command selects the entire image. Warning Do not confuse this command with the Invert layer command. 14.7.4.1 Activating the Command • You can access this command from the image menubar through Select → Invert.
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GNU Image Manipulation Program 336 / 653 14.7.6.1 Activating the Command • You can access this command from the image menubar through Select → By Color, • or by using the keyboard shortcut Shift-O. 14.7.7 From Path The From Path command transforms the current path into a selection. If the path is not closed, the command connects the two end points with a straight line. The original path is unchanged. 14.7.7.
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GNU Image Manipulation Program 337 / 653 • The Select None button. • The Select Invert button. • The Save to Channel button. • The To Path button. If you hold the Shift key while clicking on this button, the ‘Advanced Settings’ dialog is displayed. Please see the next section for details about these options. • The Stroke Selection button. The display window In the display window, selected areas of the image are white, non-selected areas are black, and partially selected areas are in shades of gray.
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GNU Image Manipulation Program 338 / 653 14.7.8.3 The ‘Selection to Path Advanced Settings’ dialog Figure 14.38: The ‘Advanced Settings’ dialog window The ‘Selection to Path Advanced Settings’ dialog contains a number of options, most of which you can set with either a slider bar or a text box. There is also one check box. These options are mostly used by advanced users. They are: • Align Threshold: If two endpoints are closer than this value, they are made to be equal.
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GNU Image Manipulation Program 339 / 653 • Filter Alternative Surround: A second number of adjacent points to consider when filtering. • Filter Epsilon: If the angles between the vectors produced by Filter Surround and Filter Alternative Surround points differ by more than this, use the one from Filter Alternative Surround. • Filter Iteration Count: The number of times to smooth the original data points. Increasing this number dramatically, to 50 or so, can produce vastly better results.
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GNU Image Manipulation Program 340 / 653 Feather selection by Enter the width of the selection border feathering. The default units are pixels, but you can also choose other units with the drop-down menu. 14.7.10 Sharpen The Sharpen command reduces the amount of blur or fuzziness around the edge of a selection. It reverses the effect of the Feather Selection command. The new edge of the selection follows the dotted line of the edge of the old selection. Anti-aliasing is also removed.
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GNU Image Manipulation Program 341 / 653 14.7.12 Grow The Grow command increases the size of a selection in the current image. It works in a similar way to the Shrink command, which reduces the size of a selection. 14.7.12.1 Activating the Command • You can access this command from the image menubar through Select → Grow. 14.7.12.2 Description of the ‘Grow Selection’ dialog Figure 14.
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GNU Image Manipulation Program 342 / 653 14.7.13 Border Figure 14.43: Example of creating a border from a selection (a) An image with a selection (b) After Select Border The Select Border command creates a new selection along the edge of an existing selection in the current image. The edge of the current selection is used as a form and the new selection is then created around it. You enter the width of the border, in pixels or some other unit, in the dialog window.
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GNU Image Manipulation Program 343 / 653 14.7.14.2 Description of the ‘Rounded Rectangle’ Dialog Window Descripción de la ventana del diálogo ‘Rectángulo redondeado’ Figure 14.45: The ‘Rounded Rectangle’ dialog Radius (%) You can enter the radius of the rounded corner in percent by using a slider or a text field. This value is a percentage of the height or the width, whichever is less.
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GNU Image Manipulation Program 344 / 653 14.7.17.1 Activating the Command • You can access this command from the image menubar through Select → To Path. • You can also access it from the Selection Editor or from the Paths Dialog which offers you a lot of Advanced Options. 14.8 The ‘View’ Menu 14.8.1 Introduction to the ‘View’ Menu Figure 14.
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GNU Image Manipulation Program 345 / 653 14.8.2.1 Activating the Command • You can access this command from the image menubar through View → New View. 14.8.3 Dot for Dot The Dot for Dot command enables and disables ‘Dot for Dot’ mode. If it is enabled (checked) and the zoom factor is 100%, every pixel in the image is displayed as one pixel on the screen. If it is disabled, the image is displayed at its ‘real’ size, the size it will have when it is printed.
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GNU Image Manipulation Program 346 / 653 14.8.4.2 Contents of the ‘Zoom’ submenu The various ‘Zoom’ submenu commands are described below, along with their default keyboard shortcuts, if any. Zoom Out (Shortcut: -) Each time ‘Zoom Out’ is used, the zoom factor is decreased by about 30%. There is a minimum zoom level of 0.39%. Zoom In (Shortcut: +) Each time ‘Zoom In’ is used, the zoom factor is increased by about 30%. The maximum possible zoom level is 25600%.
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GNU Image Manipulation Program 347 / 653 14.8.6 Full Screen The Fullscreen command enables and disables displaying the image window on the entire screen. When it is enabled, the image window takes up the whole screen, but the image stays the same size. When you enable full-screen mode, the menubar may not be displayed, but if this happens, you can right-click on the image to access the image menu. You can set the default appearance for full-screen mode in the Preferences menu.
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GNU Image Manipulation Program 348 / 653 • Print size: Shows the size the image will have when it is printed, in the current units. This is the ‘logical size’ of the image. It depends upon the physical size of the image and the screen resolution. • Resolution: Shows the image resolution in dots per inch (dpi). • Scale ratio: Shows the zoom factor of the current image. • Number of layers: Shows the number of layers in the current image. • Size in memory: Shows the number of KB the image takes up in memory.
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GNU Image Manipulation Program 349 / 653 The Comment Tab Figure 14.50: The ‘Comment’ tab of the ‘Info Window’ This tab shows the comments which can be stored in the image, depending on the data format used. 14.8.8 Navigation Window The Navigation Window command opens the navigation window. This allows you to easily navigate through the image, to set zoom levels and to move the visible parts of the image. You can find more information about using it in the Navigation dialog chapter. 14.8.8.
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GNU Image Manipulation Program 350 / 653 14.8.9.2 Description of the ‘Display Filters’ Dialog Figure 14.51: The ‘Configure Color Display Filters’ dialog This dialog has two small selectboxes. The left selectbox displays the Available Filters. You can move a filter to the right selectbox by selecting it and clicking on the right arrow button. The Active Filters window on the right displays filters you have chosen and which will be applied if the adjacent box is checked.
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GNU Image Manipulation Program 351 / 653 Deuteranopia (insensivity to green) With deuteranopia, the person has a deficiency in green vision. Deuteranopia is actually like protanopia, because the person has a loss of red and green perception, but he has no luminance loss or hue shift. Tritanopia (insensitivity to blue) With tritanopia, the person is deficient in blue and yellow perception, although he is still sensitive to red and green.
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GNU Image Manipulation Program 352 / 653 14.8.9.4 Gamma Figure 14.55: The ‘Gamma’ dialog The correspondence between electrical intensity and color brightness is not exact and it depends upon the device (the camera, the scanner, the monitor, etc.). ‘Gamma’ is a coefficient used to correct this correspondence. Your image must be visible in both dark and bright areas, even if it is displayed on a monitor with too much luminence or not enough.
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GNU Image Manipulation Program 353 / 653 14.8.9.6 Color Proof The various systems for reproducing colors cannot represent the infinity of colors available. Even if there are many colors in common between the various systems and nature, some of the colors will not be the same. The ‘gamut’ is the color range of a system. Color Profiles allow you to compensate for these differences. Before you print an image, it may be useful for you to see if you will get the result you want by applying a profile.
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GNU Image Manipulation Program 354 / 653 14.8.10.1 Activating the Command • You can access this command from the image menubar through View → Show Selection, • or by using the keyboard shortcut Ctrl-T. 14.8.11 Show Layer Boundary The Show Layer Boundary command enables and disables displaying the yellow dotted line that surrounds a layer in the image window. The dotted line is actually only visible when the layer is smaller than the image window.
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GNU Image Manipulation Program 355 / 653 14.8.14.1 Activating the Command • You can access this command from the image menubar through View → Show Grid. 14.8.15 Snap to Grid The Snap to Grid command enables and disables snap to grid. When snap to grid is enabled, the grid you set (see Show Grid) almost seems magnetic; when you move a layer or selection, the grid points appear to pull on it when it approaches. This is enormously useful for accurate placement of image elements. 14.8.15.
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GNU Image Manipulation Program 356 / 653 14.8.17.1 Activating the Command • You can access this command from the image menubar through View → Show Menubar. 14.8.18 Show Rulers The Show Rulers command enables and disables displaying the rulers. It may be useful to disable them if you are working in full-screen mode. You can set the default for the rulers in the Image Window Appearance dialog. 14.8.18.
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GNU Image Manipulation Program 357 / 653 14.9 The ‘Image’ Menu 14.9.1 The ‘Image’ Menu of the Image Window Figure 14.59: The Contents of the ‘Image’ Menu The Image menu contains commands which use or affect the entire image in some way, not just the active layer or some other specific part of the image. Note Besides the commands described here, you may also find other entries in the menu. They are not part of GIMP itself, but have been added by extensions (plug-ins).
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GNU Image Manipulation Program 358 / 653 14.9.3 Mode Figure 14.60: The ‘Mode’ submenu of the ‘Image’ menu The Mode submenu contains commands which let you change the color mode of the image. There are three modes. 14.9.3.1 Activating the Submenu • You can access this submenu from the image menubar through Image → Mode. 14.9.3.2 The Contents of the ‘Mode’ Submenu • RGB • Grayscale • Indexed • Compose • Decompose 14.9.4 RGB mode The RGB command converts your image to RGB mode.
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GNU Image Manipulation Program 359 / 653 14.9.5.1 Activating the Command • You can access this command from the image menubar through Image → Mode → Grayscale. 14.9.6 Indexed mode The Indexed command converts your image to indexed mode. See indexed colors in the Glossary for more information about Indexed Color Mode. 14.9.6.1 Activating the Command • You can access this command from the image menubar through Image → Mode → Indexed. 14.9.6.
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GNU Image Manipulation Program 360 / 653 Dithering Options Since an indexed image contains 256 colors or less, some colors in the original image may not be available in the palette. This may result in some blotchy or solid patches in areas which should have subtle color changes. The dithering options let you correct the unwanted effects created by the Palette Options.
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GNU Image Manipulation Program 361 / 653 14.9.7 Decompose With the Decompose command, you can decompose an image into its color components. You can find more information about using this command in the Decompose filter section. 14.9.7.1 Activating the Command • You can access this command from the image menubar through Image → Mode → Decompose. 14.9.8 Compose With the Compose command, you can re-compose an image that has been decomposed into its color components.
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GNU Image Manipulation Program 362 / 653 14.9.10.1 Activating the Commands • You can access the horizontal flip command from the image menubar through Image → Transform → Flip Horizontally. • You can access the vertical flip command from the image menubar through Image → Transform → Flip Vertically. 14.9.11 Rotation You can rotate the image 90 clockwise or counter-clockwise, or rotate it 180, by using the rotation commands on the Transform submenu of the Image menu.
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GNU Image Manipulation Program 363 / 653 14.9.13.2 Description of the ‘Canvas size’ dialog Figure 14.67: The ‘Canvas size’ dialog C ANVAS S IZE Width; Height You can set the Width and the Height of the canvas. The default units are pixels but you can choose different units, e.g. percent, if you want to set the new dimensions relative to the current dimensions. If the Chain to the right of the Width and Height is not broken, both Width and Height keep the same relative size to each other.
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GNU Image Manipulation Program 364 / 653 14.9.14 Fit Canvas to Layers The Fit Canvas to Layers command adapts the canvas size (that is, the drawing area) to the size of the largest layer in the image, in both width and height. 14.9.14.1 Activating the command • You can access this command from the image menubar through Image → Fit Canvas to Layers. 14.9.15 Print Size You can use the Print Size dialog to change the dimensions of a printed image and its resolution.
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GNU Image Manipulation Program 365 / 653 14.9.16 Scale Image The Scale Image command enlarges or reduces the physical size of the image by changing the number of pixels it contains. It changes the size of the contents of the image and resizes the canvas accordingly. It operates on the entire image. If your image has layers of different sizes, making the image smaller could shrink some of them down to nothing, since a layer cannot be less than one pixel wide or high.
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GNU Image Manipulation Program 366 / 653 next to the Width and Height boxes is unbroken, the Width and Height will stay in the same proportion to each other. If you break the chain by clicking on it, you can set them independently, but this will distort the image. However, you do not have to set the dimensions in pixels. You can choose different units from the drop-down menu. If you choose percent as the units, you can set the image size relative to its original size.
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GNU Image Manipulation Program 367 / 653 14.9.18 Autocrop Image The Autocrop Image command removes the borders from an image. It searches the active layer for the largest possible border area that is all the same color, and then crops this area from the image, as if you had used the Crop tool. Caution Note carefully that this command only uses the active layer of the image to find borders. If other layers have color variations extending into the border zone of the active layer, they are cropped away.
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GNU Image Manipulation Program 368 / 653 14.9.20.1 Activating the Command • You can access this command from the image menubar through Image → Merge Visible Layers, • or by using the keyboard shortcut Ctrl-M. 14.9.20.2 Description of the ‘Merge Visible Layers’ Dialog Figure 14.71: The ‘Merge Visible Layers’ Dialog Final, Merged Layer should be: Visible layers are the layers which are marked with an ‘eye’ icon in the Layers dialog.
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GNU Image Manipulation Program 369 / 653 This operation makes significant changes to the structure of the image. It is normally only necessary when you would like to save an image in a format which does not support levels or transparency (an alpha channel). 14.9.21.1 Activating the Command • You can access this command from the image menubar through Image → Flatten Image. 14.9.22 Guides Figure 14.
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GNU Image Manipulation Program 370 / 653 14.9.23.2 ‘New Guide’ Options Figure 14.74: The ‘New Guide’ Dialog Direction ; Position When you select New Guide, a dialog opens, which allows you to set the Direction and Position, in pixels, of the new guide more precisely than by using click-and-drag. The Direction may be Horizontal or Vertical. The coordinate origin for the Position is the upper left corner of the image. 14.9.
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GNU Image Manipulation Program 371 / 653 14.9.25.1 Activating the Command • You can access this command from the image menubar through Image → Guides → New Guides from Selection. 14.9.26 Remove all guides The Remove all Guides command removes all guides from the image. 14.9.26.1 Activating the Command • You can access this command from the image menubar through Image → Guides → Remove all guides. 14.9.
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GNU Image Manipulation Program 372 / 653 Dashed This style shows dashed lines in the foreground color of the grid. If the lines are too close together, the grid won’t look good. Double dashed This style shows dashed lines, where the foreground and background colors of the grid alternate. Solid This style shows solid grid lines in the foreground color of the grid. Foreground and Background colors Click on the color dwell to select a new color for the grid.
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GNU Image Manipulation Program 373 / 653 14.10.2.1 Activating the Command • You can access this command from the image menubar through Layer → New Layer. 14.10.2.2 Description of the ‘New Layer’ Dialog Figure 14.78: The ‘New Layer’ dialog Layer Name The name of the new layer. It does not have any functional significance; it is simply a convenient way for you to remember the purpose of the layer. The default name is ‘New Layer’.
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GNU Image Manipulation Program 374 / 653 Note If there is an active selection tool, the mouse pointer is displayed with an anchor icon when it is outside of the selection. A left click then anchors the floating selection. You may also click on the New layer command on the Layers dialog, which anchors the floating selection to a new layer. See Section 14.10.2. 14.10.4.
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GNU Image Manipulation Program 375 / 653 Figure 14.79: Layer Text Discard command When you add text to an image, GIMP adds specific informations. This command lets you discard these informations, transforming the current text layer into a normal bitmap layer. The reason to do that is not evident. Note that this transformation of text into bitmap is automatically performed when you apply a graphic operation to the text layer.
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GNU Image Manipulation Program 376 / 653 • Section 14.10.10 • Section 14.10.11 • Section 14.10.12 • Section 14.10.13 • Section 14.10.14 • Section 14.10.15 • Section 14.10.16 14.10.9 Select Previous Layer The Select Previous Layer command selects the layer just above the active layer in the layer stack. The command highlights the layer in the Layers Dialog and makes it the new active layer. If the active layer is already at the top of the stack, this menu entry is insensitive and grayed out.
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GNU Image Manipulation Program 377 / 653 14.10.10.1 Activating the Command • You can access this command from the image menubar through Layer → Stack → Select Next Layer, • or by using the keyboard shortcut Page_Down, • or the ‘Down-arrow’ key, • or simply by clicking on the layer name in Layers Dialog. 14.10.11 Select Top Layer The Select Top Layer command makes the top layer in the stack the active layer for the image and highlights it in the Layers dialog.
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GNU Image Manipulation Program 378 / 653 14.10.13.1 Activating the Command • You can access this command from the image menubar through Layer → Stack → Raise Layer, • or by clicking on the up-arrow icon at the bottom of the Layers dialog. 14.10.14 Lower Layer The Lower layer command lowers the active layer one position in the layer stack. If the active layer is already at the bottom of the stack or if there is only one layer, this menu entry is insensitive and grayed out. 14.10.14.
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GNU Image Manipulation Program 379 / 653 14.10.17 The ‘Colors’ Submenu Figure 14.81: The ‘Colors’ submenu The Colors submenu contains operations which alter colors within the active layer. The operations at the top of the list access the Color tools for the image. These are described in the Toolbox chapter. Warning This command operates only on the layer which is active at the time the command is called.
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GNU Image Manipulation Program 380 / 653 14.10.18.1 Activating the Command • You can access this command from the image menubar through Layer → Colors → Desaturate. 14.10.19 Invert The Invert command inverts all the pixel colors and brightness values in the current layer, as if the image were converted into a negative. Dark areas become bright and bright areas become dark. Hues are replaced by their complementary colors. For more information about colors, see the Glossary entry about Color Model.
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GNU Image Manipulation Program 381 / 653 Here are examples of the results of these commands, all together on one page, so you can compare them more easily. The most appropriate command depends upon your image, so you should try each of them to see which command works best on it. El GIMP tiene varios comandos automáticos para extender las columnas del histograma para los canales de color de la capa activa.
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GNU Image Manipulation Program 382 / 653 Figure 14.86: The ‘Color Enhance’ command Color Enhance Figure 14.87: The ‘Normalize’ command Normalize Figure 14.88: The ‘Stretch Contrast’ command Stretch Contrast Figure 14.
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GNU Image Manipulation Program 383 / 653 14.10.21 The ‘Auto’ Submenu Figure 14.90: The ‘Colors/Auto’ submenu The Auto submenu contains operations which automatically adjust the distribution of colors in the active layer, without requiring any input from the user. Several of these operations are actually implemented as plugins. 14.10.21.1 Activating the submenu • You can access this submenu from the image window through Layer → Colors → Auto. 14.10.21.
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GNU Image Manipulation Program 384 / 653 14.10.22.2 ‘Equalize Layer’ example Figure 14.91: Original image The active layer and its Red, Green, Blue histograms before Equalize. Figure 14.92: Image after the command The active layer and its Red, Green, Blue histograms after treatment. Histogram stretching creates gaps between pixel columns giving it a striped look. 14.10.
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GNU Image Manipulation Program 385 / 653 14.10.23.2 ‘White Balance’ example Figure 14.93: Original image The active layer and its Red, Green and Blue histograms before White Balance. Figure 14.94: Image after the command The active layer and its Red, Green and Blue histograms after White Balance. Poor white areas in the image became pure white. Histogram stretching creates gaps between the pixel columns, giving it a striped look. 14.10.
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GNU Image Manipulation Program 386 / 653 14.10.24.2 ‘Color Enhance’ example Figure 14.95: ‘Color Enhance’ example (Original image) The active layer and its Red, Green and Blue histograms before Color Enhance. Figure 14.96: ‘Color Enhance’ example (Image after the command) The active layer and its Red, Green and Blue histograms after Color Enhance. The result may not always be what you expect. 14.10.
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GNU Image Manipulation Program 387 / 653 Figure 14.98: ‘Normalize’Example (Image after the command) The active layer and its Red, Green and Blue histograms after Normalize. The contrast is enhanced. Histogram stretching creates gaps between the pixel columns, giving it a striped look. 14.10.26 Stretch Contrast The Stretch Contrast command automatically stretches the histogram values in the active layer.
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GNU Image Manipulation Program 388 / 653 Figure 14.100: Image after the command The layer and its Red and Green and Blue histograms after Stretch Contrast. The pixel columns do not reach the right end of the histogram (255) because of a few very bright pixels, unlike White Balance. Histogram stretching creates gaps between the pixel columns, giving it a striped look. 14.10.
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GNU Image Manipulation Program 389 / 653 14.10.28 Autocrop Layer The Autocrop Layer command automatically crops the active layer, unlike the Crop Tool, or the Crop Layer command which let you manually define the area to be cropped. This command removes the largest possible area around the outside edge which all has the same color. It does this by scanning the layer along a horizontal line and a vertical line and cropping the layer as soon as it encounters a different color, whatever its transparency.
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GNU Image Manipulation Program 390 / 653 14.10.29.2 The Contents of the ‘Mask’ Submenu The Mask submenu contains the following commands: • Section 14.10.30 • Section 14.10.31 • Section 14.10.32 • Section 14.10.35 • Section 14.10.33 • Section 14.10.34 • Section 14.10.36 • Section 14.10.37 • Section 14.10.38 • Section 14.10.39 14.10.30 Add Layer Mask The Add Layer Mask command adds a layer mask to the active layer. It displays a dialog in which you can set the initial properties of the mask.
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GNU Image Manipulation Program 391 / 653 Initialize Layer Mask to This dialog allows you six choices for the initial contents of the layer mask: White (full opacity) With this option, the layer mask will make all of the layer fully opaque. That means that you will not notice any difference in the appearance of the layer until you paint on the layer mask. Black (full transparency) With this option, the layer mask will make all of the layer fully transparent.
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GNU Image Manipulation Program 392 / 653 14.10.33.1 Activating the Command • You can access this command from the image menubar through Layer → Mask → Edit Layer Mask. • You can undo this action by unchecking the menu entry in the Layer → Mask menu or by clicking on the layer component in the Layers Dialog. 14.10.34 Disable Layer Mask As soon as you create a layer mask, it acts on the image. The Disable Layer Mask command allows you to suspend this action.
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GNU Image Manipulation Program 393 / 653 14.10.36.2 Illustration of ‘Layer Mask to Selection’ Figure 14.106: Illustration of ‘Layer Mask to Selection’ From left to right: the original image with a selection, the Layers Dialog with a layer mask created with the Layer’s alpha channel option, after Mask to Selection. 14.10.
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GNU Image Manipulation Program 394 / 653 14.10.38.2 Illustration of Subtract Layer Mask from Selection Figure 14.108: Illustration of Subtract Layer Mask from Selection From left to right: the original image with a selection, the Layers Dialog with a layer mask created with the Layer’s alpha channel option, after Subtract from Selection. 14.10.39 Intersect Layer Mask with Selection The Intersect with Selection command converts the layer mask of the active layer into a selection.
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GNU Image Manipulation Program 395 / 653 The Transparency submenu contains commands which use or affect the alpha channel of the active layer. 14.10.40.1 Activating the Submenu • You can access this submenu from the image menubar through Layer → Transparency. 14.10.40.2 The Contents of the ‘Transparency’ Submenu The Transparency submenu contains the following commands: • Section 14.10.41 • Section 14.10.42 • Section 14.10.43 • Section 14.10.44 • Section 14.10.45 • Section 14.10.46 • Section 14.10.
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GNU Image Manipulation Program 396 / 653 14.10.43.1 Activating the Command • You can access this command from the image menubar through Layer → Transparency → Semi-flatten. 14.10.44 Threshold Alpha The Threshold Alpha command converts semi-transparent areas of the active layer into completely transparent or completely opaque areas, based on a threshold you set, between 0 and 255. It only works on layers of RGB images which have an alpha channel.
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GNU Image Manipulation Program 397 / 653 14.10.45.2 Example Figure 14.112: Applying ‘Alpha to Selection’ (a) 14.10.46 (b) Non-transparent pixels of the active layer have replaced the existing rectangular selection. Add Alpha channel to Selection The Add to Selection command creates a selection in the current layer from the Alpha Channel. Opaque pixels are fully selected, transparent pixels are unselected, and translucent pixels are partially selected.
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GNU Image Manipulation Program 398 / 653 existing selection. The Alpha channel itself is not changed. 14.10.47.1 Activating the Command • You can access this command from the image menubar through Layer → Transparency → Subtract from Selection • or from the pop-up menu which appears when you right-click on the active layer in the Layer Dialog. 14.10.47.2 Example Figure 14.114: Applying ‘Subtract from Selection’ (a) 14.10.
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GNU Image Manipulation Program 399 / 653 14.10.48.2 Example Figure 14.115: Applying ‘Intersect with Selection’ (a) 14.10.49 (b) Non-transparent pixels of the active layer have been intersected with the existing rectangular selection. The ‘Transform’ Submenu Figure 14.116: The ‘Transform’ Submenu of the ‘Layer’ menu The Transform submenu of the Layer menu contains commands which flip or rotate the active layer of the image. 14.10.49.
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GNU Image Manipulation Program 400 / 653 14.10.50 Flip Horizontally The Flip Horizontally command reverses the active layer horizontally, that is, from left to right. It leaves the dimensions of the layer and the pixel information unchanged. 14.10.50.1 Activating the Command • You can access this command from the image menubar through Layer → Transform → Flip Horizontally. 14.10.50.2 Example Figure 14.
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GNU Image Manipulation Program 401 / 653 14.10.53 Rotate 90 degrees CCW The Rotate 90 degrees CCW command rotates the active layer by 90 counter-clockwise around the center of the layer, with no loss of pixel data. The shape of the layer is not altered, but the rotation may cause the layer to extend beyond the bounds of the image. This is allowed in GIMP and it does not mean that the layer is cropped.
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GNU Image Manipulation Program 402 / 653 14.10.56.2 Description of the ‘Offset’ dialog Figure 14.118: The ‘Offset’ dialog Offset X; Y With these two values, you specify how far the contents of the layer should be shifted in the horizontal (X) and vertical (Y) directions. You can enter the offsets in the text boxes. Positive values move the layer to the right and downward. The default unit is pixels, but you can choose a different unit of measurement with the drop-down menu.
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GNU Image Manipulation Program 403 / 653 14.10.57.2 Description of the ‘Layer Boundary Size’ dialog Figure 14.119: The ‘Layer Boundary Size’ Dialog Layer Size Width; Height When the dialog is displayed, the original dimensions of the active layer are shown. You can change them by using the two text boxes. If these boxes are linked together with a chain, the width-to-height ratio is automatically maintained. If you break the chain by clicking on it, you can set the dimensions independently of each other.
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GNU Image Manipulation Program 404 / 653 14.10.59.1 Activating the Command • You can access this command from the image menubar through Layer → Scale Layer. 14.10.59.2 Description of the ‘Scale Layer’ Dialog Figure 14.120: The ‘Scale Layer’ dialog Layer Size When you enlarge a layer, GIMP has to calculate new pixels from the existing ones. This procedure is called ‘interpolation’.
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GNU Image Manipulation Program 405 / 653 14.10.60.1 Activating the Command • You can access this command from the image menubar through Layer → Crop layer. 14.10.60.2 Example Figure 14.121: Applying ‘Layer Crop’ On the left: before applying the command, the layer has a selection that has feathered edges. On the right: after applying the command, the non-transparent pixels are not cropped, even if they are only partially transparent. 14.10.
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GNU Image Manipulation Program 406 / 653 14.10.61.2 Description of the ‘Layer Align’ dialog Figure 14.123: The ‘Layer Align’ dialog Horizontal Style; Vertical Style These options control how the layers should be moved in relationship to each other. You can choose: • None: There will be no change in the horizontal or the vertical position, respectively. • Collect: The visible layers will be aligned on the canvas, in the way that is determined by the Horizontal base and Vertical base options.
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GNU Image Manipulation Program 407 / 653 • Fill (left to right); Fill (top to bottom): The visible layers will be aligned with the canvas according to the edge you selected with Horizontal base or Vertical base, respectively. The layers are arranged regularly, so that they do not overlap each other. The top layer in the stack is placed on the leftmost (or uppermost) position in the image. The bottom layer in the stack is placed on the rightmost (or bottommost) position of the image.
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GNU Image Manipulation Program 408 / 653 Figure 14.128: Vertical ‘Fill’ alignment (bottom layer) (a) Original image with the layer stack (b) Vertical Fill alignment, bottom to top, bottom layer as base There must be at least three visible layers in the image to use the ‘Fill’ options. 14.11 The ‘Tools’ Menu 14.11.1 Introduction to the ‘Tools’ Menu Figure 14.129: Contents of the ‘Tools’ menu The menu entries on the Tools menu access the GIMP tools.
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GNU Image Manipulation Program 409 / 653 14.12 The ‘Filters’ Menu 14.12.1 Menu ‘Filters’ Introduction Figure 14.130: The ‘Filters’ menu In GIMP terminology, a filter is a plug-in that modifies the appearance of an image, in most cases just the active layer of the image. Not all of the entries in this menu meet that definition, however; the word ‘filter’ is often mis-used to mean any plug-in, regardless of what it does. Indeed, some of the entries in this menu do not modify images at all.
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GNU Image Manipulation Program 410 / 653 14.12.2.1 Activating the Command • You can access this command from the image menubar through Filters → Repeat filter , • or by using the keyboard shortcut Ctrl-F. 14.12.3 Re-show Last The Re-show Last command interactively runs the most recently executed plug-in. Unlike the ‘Repeat Last’ command, which does not display a dialog, the ‘Re-show Last’ command displays a dialog window, if the plug-in has one.
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GNU Image Manipulation Program 411 / 653 Chapter 15 Filters 15.1 Introduction A filter is a special kind of tool designed to take an input layer or image, apply a mathematical algorithm to it, and return the input layer or image in a modified format. GIMP uses filters to achieve a variety of effects and those effects are discussed here. The filters are divided into several categories: • Blur see Section 15.2. • Colors see Section 15.3. • Noise see Section 15.4. • Edge-Detect see Section 15.5.
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GNU Image Manipulation Program 412 / 653 15.1.1 Preview Most filters have a Preview where changes in the image are displayed, in real time (if the ‘Preview’ option is checked), before being applied to the image. Figure 15.1: Preview submenu Right clicking on the Preview window opens a submenu which lets you set the Style and the Size of checks representing transparency. 15.2 Blur Filters 15.2.1 Introduction Figure 15.
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GNU Image Manipulation Program 413 / 653 Figure 15.4: Simple blur If you only want to blur the image a little bit--to soften it, as it were--you might use the simple "Blur" filter. In GIMP 2.2 this runs automatically, without creating a dialog. The effect is subtle enough that you might not even notice it, but you can get a stronger effect by repeating it. In GIMP 2.0 the filter shows a dialog that allows you to set a "repeat count".
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GNU Image Manipulation Program 414 / 653 The Motion Blur filter blurs in a specific direction at each point, which allows you to create a sense of motion: either linear, radial, or rotational. Finally, the Tileable Blur filter is really the same thing as a Gaussian blur, except that it wraps around the edges of an image to help you reduce edge effects when you create a pattern by tiling multiple copies of the image side by side.
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GNU Image Manipulation Program 415 / 653 15.2.3 Gaussian Blur 15.2.3.1 Overview Figure 15.9: From left to right: original, filter applied. (a) Original (b) Blur applied You can find this filter in the image menu under Filters → Blur → Gaussian Blur The IIR Gaussian Blur plug-in acts on each pixel of the active layer or selection, setting its Value to the average of all pixel Values present in a radius defined in the dialog. A higher Value will produce a higher amount of blur.
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GNU Image Manipulation Program 416 / 653 15.2.4 Selective Gaussian Blur 15.2.4.1 Overview Figure 15.11: The Selective Gaussian Blur filter (a) Original (b) Blur applied You can find this filter in the image menu under Filters → Blur → Selective Gaussian Blur Contrary to the other blur plug-ins, the Selective Gaussian Blur plug-in doesn’t act on all pixels: blur is applied only if the difference between its value and the value of the surrounding pixels is less than a defined Delta value.
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GNU Image Manipulation Program 417 / 653 15.2.5 Motion Blur 15.2.5.1 Overview Figure 15.13: Starting example for Motion Blur filter (a) Original image (b) Linear blur Figure 15.
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GNU Image Manipulation Program 418 / 653 The Motion Blur filter creates a movement blur. The filter is capable of Linear, Radial, and Zoom movements. Each of these movements can be further adjusted, with Length, or Angle settings available. 15.2.5.2 Options Figure 15.15: ‘Motion Blur’ filter options Blur Type Linear Linear motion is a blur that travels in a single direction, horizontally, for example. In this case, Length means as Radius in other filters:it represents the blur intensity.
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GNU Image Manipulation Program 419 / 653 15.2.6 Pixelise 15.2.6.1 Overview Figure 15.16: From left to right: Before and after applying Pixelise filter (a) Original (b) Blur applied You can find this filter in the image menu under Filters → Blur → Pixelise The Pixelize filter renders the image using large color blocks. It is very similar to the effect seen on television when obscuring a criminal during trial. It is used for the ‘Abraham Lincoln effect’: see [?]. 15.2.6.2 Options Figure 15.
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GNU Image Manipulation Program 420 / 653 15.2.7 Tileable Blur 15.2.7.1 Overview Figure 15.18: From left to right: original, tileable blur applied (a) Original (b) Filter Tileable Blur applied You can find this filter in the image menu under Filters → Blur → Tileable Blur This tool is used to soften tile seams in images used in tiled backgrounds. It does this by blending and blurring the boundary between images that will be next to each other after tiling.
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GNU Image Manipulation Program 421 / 653 Blur Radius The bigger the radius, the more marked is the blur. By selecting Horizontal and Vertical, you can make the horizontal and vertical borders tileable. Blur Type IIR: for photographic or scanned images. RLE: for computer-generated images. 15.3 Color filters 15.3.1 Introduction The Color filters group contains several filters to modify colors in an image, a layer or a selection.
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GNU Image Manipulation Program 422 / 653 15.3.3 Alien Map 2 15.3.3.1 Overview Figure 15.21: Alien Map 2 filter example (a) Original image (b) Filter applied You can find this filter through Filters → Colors → Map → Alien map 2. This filter renders very modified colors by applying trigonometric functions. Alien Map 2 can work on RGB and HSV. 15.3.3.2 Options Figure 15.22: Options for the ‘Alien Map 2’ filter Preview This preview displays results of filter application interactively.
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GNU Image Manipulation Program 423 / 653 Frequency around 0.3 to 0.7 provides a curve that is similar to the linear function (original image), only darker or with more contrast. As you raise the frequency level, you’ll get an increasing variation in pixel transformation, meaning that the image will get more and more ‘alien’. Phase alters the value transformation. 0 and 360 degrees are the same as a sine function and 90 is the same as a cosine function. 180 inverts sine and 270 inverts cosine.
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GNU Image Manipulation Program 424 / 653 15.3.4.2 Options Figure 15.24: Option of the ‘Two color exchange’ filter Preview In this preview, a part of the Image is displayed. A selection smaller than preview will be complete in preview. A bigger one will be cut out to be adapted to the preview. If you middle-click inside preview , the clicked pixel color will be selected and will appear as From Color.
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GNU Image Manipulation Program 425 / 653 15.3.5 Colormap Rotation 15.3.5.1 Overview Figure 15.25: From left to right: Original image, after applying filter (a) Original image (b) Filter Color Map Rotation applied You can find this filter through Filters → Colors → Map → Color Map Rotation. Colormap Rotation lets you exchange one color range to another range. 15.3.5.2 Main Options Figure 15.
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GNU Image Manipulation Program 426 / 653 From The Color Circle: Two axis to define "From" range. The curved arrow in angle lets to recognise "From" axis and "To" axis of range. Click-drag these axis to change range. Switch to Clockwise/Counterclockwise: Sets the direction the range is going. Change Order of Arrows: Inverts From and To axis. This results in an important color change as colors in selection angle are different. Select All selects the whole color circle.
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GNU Image Manipulation Program 427 / 653 Figure 15.28: Grey Mode The small circle is on yellow and mode is "Change to this". Blue has changed to yellow. Note that Grey and White did so too. Gray Threshold Figure 15.29: Gray Threshold Grey-threshold is 0.25: the blue sector (sat 0.25) has turned to Grey (Note that Grey and White, that are 0% Sat., are not concerned). You specify there how much saturation will be considered grey.
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GNU Image Manipulation Program 428 / 653 Black to White gradient, progressively filled with color, as threshold increases. 15.3.5.4 Previews Original and Rotated The Original preview displays a thumbnail of the original image and the Rotated preview displays color changes interactively, before they are applied to the Image. Continuous Update Continuous Update displays color changes continuously in the Rotated preview.
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GNU Image Manipulation Program 429 / 653 15.3.6 Map Color Range 15.3.6.1 Overview Figure 15.30: Example for the Map Color Range filter (a) Original image (b) Filter Map Color Range applied This filter is found in Filters → Colors → Map → Color Range Mapping. Unlike Exchange filter, Map Color Range maps a defined color range against another defined color range.
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GNU Image Manipulation Program 430 / 653 Preview Preview: This Preview displays color changes interactively, before they are applied to Image. Color Source Range The two Color Swatch Boxes allow you to define From and To limits of source color range. Default colors are the Foreground and the Background colors of the Toolbox, but, when you click on a box, you call the Gimp Color selector which lets you select other colors. Note that, when you select a color, you really select three separate color channels.
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GNU Image Manipulation Program 431 / 653 15.3.7.2 Options Figure 15.33: Options of the ‘Sample Colorize’ filter The filter window is divided into two parts: Destination on the left, Sampling on the right. Destination, Sample By default, displayed image previews reproduce the image you invoked the filter from. The sample can be the whole preview, or a selection of this preview.
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GNU Image Manipulation Program 432 / 653 Apply Button When you are satisfied with the result on destination preview, click on Apply to apply results onto destination image. Hold Intensity If this option is checked, the average light intensity of destination image will be the same as that of source image. Original Intensity If this option is checked, the In levels intensity settings will not be taken in account: original intensity will be preserved. 15.3.8 Gradient Map 15.3.8.1 Overview Figure 15.
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GNU Image Manipulation Program 433 / 653 15.3.9.2 Options Figure 15.35: Options of the ‘Border Average Filter’ Border Size You can set there the border Thickness in pixels. Number of Colors The Bucket Size lets you control the number of colors considered as similar and counted with the same ‘bucket’. A low bucket size value (i.e. a high bucket number) gives you better precision in the calculation of the average color.
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GNU Image Manipulation Program 434 / 653 Here the bucket size is high, the number of buckets low. The filter looks at only the two most significant bits of every color channel value. Now Green (0-63,192-255,0-63) is the most frequent color. The resulting color is Green (32,224,32), which is the average of all colors possibly counted by this ‘bucket’. 15.3.10 Channel Mixer 15.3.10.1 Overview Figure 15.
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GNU Image Manipulation Program 435 / 653 Output Channel From this menu you select the channel to mix to. Choices are Red, Green, or Blue. It is insensitive when Monochrome option is checked. Red, Green, Blue These three sliders set the contribution of red, green or blue channel to output. Can be negative. These sliders are graduated from -200 to 200. They represent the percentage which will be attributed to the output channel. 100% corresponds to the value of the channel of the studied pixel in the image.
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GNU Image Manipulation Program 436 / 653 Figure 15.43: Output channel is red. Green Channel +50%. The Preserve Luminosity option is checked. The values attributed to the Red Output channel are lower, preventing a too much clear image. In Monochrome mode When this option is checked, the image preview turns to grayscale, but the image is still a RGB image with three channels, until the filter action is validated. Figure 15.44: Monochrome option checked. Red:100% Green: 50% Blue: 0%.
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GNU Image Manipulation Program 437 / 653 15.3.11 Colorcube Analysis 15.3.11.1 Overview Figure 15.45: From left to right: Original image, after Colorcube Analysis of the image (a) Original image (b) Filter Colorcube Analysis applied You can find this filter through Filters → Colors → Colorcube Analysis. It gives data about image: dimensions, file size, color number, compression ratio... 15.3.12 Colorify 15.3.12.1 Overview Figure 15.
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GNU Image Manipulation Program 438 / 653 15.3.12.2 Options Figure 15.47: ‘Colorify’ filter options Color A color palette is available and you can select your own color by clicking on the Custom Color swatch. 15.3.13 Color to Alpha 15.3.13.1 Overview Figure 15.
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GNU Image Manipulation Program 439 / 653 You can find this filter through Filters → Colors → Color to Alpha. The Color to Alpha filter makes transparent all pixels with a selected color. An Alpha channel is created. It will attempt to preserve anti-aliasing information by using a partially intelligent routine that replaces weak color information with weak alpha information. In this way, areas that contain an element of the selected color will maintain a blended appearance with their surrounding pixels. 15.
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GNU Image Manipulation Program 440 / 653 15.3.14.2 Options Figure 15.50: ‘Decompose’ filter options Decompose to Layers If this option is checked, a new grey-scaled image is created, with each layer representing one of the channels of the selected mode. If this option is not checked, every channel is represented with a specific image automatically and clearly named in the name bar. Following options are described with ‘Decompose to layers ’checked.
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GNU Image Manipulation Program 441 / 653 LAB Decomposing This option decomposes image into three greyscaled layers, layer "L" for Luminance, layer "A" for colors between green and red, layer "B" for colors between blue and yellow. The LAB Decomposing is a color model of the Luminance-Color family. A channel is used for the Luminosity while two other channels are used for the Colors. The LAB color model is used by Photoshop. YCbCr Decomposing In GIMP there is four YCbCr decompositions with different values.
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GNU Image Manipulation Program 442 / 653 15.3.15.2 Options Figure 15.52: ‘Compose’ filter options Compose Channels You can select there the color space to be used: RGB, HSV... The options are described in the following Decompose plug-in. Channel Representation Allows you to select which channel will be affected to each image channel. Tip If Compose options are different from Decompose ones, for instance an image decomposed to RGB then recomposed to LAB, you will get interesting color effects.
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GNU Image Manipulation Program 443 / 653 This tool offers you a collection of unified filters to treat the image. Of course, same functions can be performed by particular filters, but you have here an interesting, intuitive, overview. 15.3.16.2 Starting filter Ejecutar el filtro You can find this filter through Filters → Colors → Filter Pack. 15.3.16.3 Options Figure 15.
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GNU Image Manipulation Program 444 / 653 Figure 15.55: Hue option of the ‘Filterpack’ filter • Saturation: Three previews for more or less saturation. Figure 15.56: The saturation option of the ‘Filterpack’ filter • Value: Three previews for more or less luminosity. Figure 15.57: Value option of the ‘Filterpack’ filter • Advanced: developed later. Affected range Affected Range allows you to set which brightness you want to work with. • Shadows: dark tones.
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GNU Image Manipulation Program 445 / 653 Roughness This slider sets how image will change when you click on a window: taking a short step or a large one (0 - 1). Advanced Options Figure 15.58: Advanced options of the ‘Filterpack’ filter These advanced options let you work more precisely on the changes applied to the image and on the preview size. Preview Size Something like a zoom on previews. Normal size is 80. Tip In spite of Preview Size option, this size is often too small.
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GNU Image Manipulation Program 446 / 653 15.3.17.2 Options Mode You have to select the TV mode: PAL or NTSC. Action You can select: • Reduce Luminency • Reduce Saturation • Blacken: this will turn hot pixels to black. Create a new layer With this option, work will be performed on a new layer instead of the image. This will give you peace of mind! 15.3.18 Max RGB 15.3.18.1 Overview Figure 15.
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GNU Image Manipulation Program 447 / 653 15.3.18.2 Options Preview This preview displays, in real time, the resulting image after treatment by filter. Parameter Settings Hold the maximal channels: For every pixel, the filter keeps intensity of the RGB color channel which has the maximal intensity and reduces other both to zero. For example: 220, 158, 175 max--> 220, 0, 0. If two channels have same intensity, both are held: 210, 54, 210 max--> 210, 0, 210.
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GNU Image Manipulation Program 448 / 653 15.3.19.3 Options Figure 15.61: ‘Retinex’ filter options These options call for notions that only mathematicians can understand. In actual practice, user has to grope about for the best setting. Level Here is what the plug-in author writes on his site (www-prima.inrialpes.fr/pelisson/MSRCR.php): ‘To characterize color variations and the lightor, we make a difference between (gaussian) filters responses at different scales.
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GNU Image Manipulation Program 449 / 653 15.3.20.2 Example Figure 15.62: Toolbox Background color (pink) and an image with feathered edges on a transparent background, at a 800% zoom level. (a) (b) Figure 15.63: Result, in GIF format, after applying Semi-flatten filter. Full transparency is kept. Semi-tranparent pixels are colored with pink according to their transparency (Alpha value). This image will well merge into the pink background of the new page. 15.3.
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GNU Image Manipulation Program 450 / 653 15.3.21.1 Overview Figure 15.64: From left to right: original image, after applying Smooth Palette filter (a) Original image (b) Filter Smooth Palette applied You can find this filter through Filters → Colors → Smooth Palette. It creates a striped palette from colors in active layer or selection. The main purpose of this filter is to create color-maps to be used with the Flame filter. 15.3.21.
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GNU Image Manipulation Program 451 / 653 You can find this filter through Filters → Colors → Value Invert This filter inverts Value (luminosity) of the active layer or selection. Hue and Saturation will not be affected, although the color will sometimes be slightly different because of round-off error. If you want to invert Hue and Saturation also, use Layers → Colors → Invert.
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GNU Image Manipulation Program 452 / 653 15.4.2.2 Options Figure 15.67: ‘Hurl’ options Random Seed Random Seed controls randomness of hurl. If the same random seed in the same situation is used, the filter produces exactly the same results. A different random seed produces different results. Random seed can be entered manually or generated randomly by pressing New Seed button.
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GNU Image Manipulation Program 453 / 653 The result is very naturally looking noise. This filter does not work with indexed images. Resultatet ser svært naturleg ut. Filteret verkar ikkje på indekserte bilete. 15.4.3.2 Options Figure 15.69: ‘Scatter RGB’ filter options Preview This preview displays interactively changes before they are applied to the image. Correlated noise When checked, this radio button makes sliders R, G and B to move all together.
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GNU Image Manipulation Program 454 / 653 15.4.4 Pick 15.4.4.1 Overview Figure 15.70: Example of applying the ‘Pick’ filter (a) Original image (b) Filter Pick applied You can find this filter through Filters → Noise → Pick. The Pick filter replaces each affected pixel by a pixel value randomly chosen from its eight neighbours and itself (from a 3×3 square the pixel is center of).
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GNU Image Manipulation Program 455 / 653 15.4.5 Scatter HSV 15.4.5.1 Overview Figure 15.72: Example of applying the Pick HSV filter (a) Original image (b) Filter Pick HSV applied You can find this filter through Filters → Noise → Scatter HSV. The Scatter HSV filter creates noise in the active layer or selection by using the Hue, Saturation, Value (luminosity) color model. 15.4.5.2 Options Figure 15.
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GNU Image Manipulation Program 456 / 653 Saturation Slider This slider increases saturation of scattered pixels. Value Slider This slider increases brightness of scattered pixels. 15.4.6 Slur 15.4.6.1 Overview Figure 15.74: Example of applying the Slur filter (a) Original image (b) Filter Slur applied You can find this filter through Filters → Noise → Slur.
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GNU Image Manipulation Program 457 / 653 Randomization (%) The Randomization slider represents the percentage of pixels of the active layer or selection which will be slurred. The higher value, the more pixels are slurred, but because of the way the filter works, its effect is most noticeable if this slider is set to a medium value, somewhere around 50. Experiment with it and try for yourself! Repeat The Repeat slider represents the number of times the filter will be applied.
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GNU Image Manipulation Program 458 / 653 15.5 Edge-Detect Filters 15.5.1 Introduction Edge detect filters search for borders between different colors and so can detect contours of objects. They are used to make selections and for many artistic purposes. Most of them are based on gradient calculation methods and give thick border lines. Look at fig.1 which represents color intensity variations. On the left is a slow color gradient which is not a border.
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GNU Image Manipulation Program 459 / 653 15.5.2 Difference of Gaussians 15.5.2.1 Overview Figure 15.78: Applying example for the Difference of Gaussians filter (a) Original image (b) Filter applied You can find this filter through Filters → Edge detect → Difference of Gaussians This filter is new in GIMP 2.2.
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GNU Image Manipulation Program 460 / 653 Smoothing parameters Radius 1 and Radius 2 are the blurring radii for the two Gaussian blurs. The only constraints on them is that they cannot be equal, or else the result will be a blank image. If you want to produce something that looks like a sketch, in most cases setting Radius 2 smaller than Radius 1 will give better results. Normalize Checking this box causes the brightness range in the result to be stretched as much as possible, increasing contrast.
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GNU Image Manipulation Program 461 / 653 Figure 15.82: Applying example for the Edge filter (a) After applying the filter (Roberts option) (b) Figure 15.
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GNU Image Manipulation Program 462 / 653 15.5.3.2 Options Figure 15.84: Edge filter options Algorithm Edge detector offers several detection methods: • Sobel: Here, this method has no options and so is less interesting than the specific Sobel. • Prewitt: Result doesn’t look different from Sobel. • Gradient: Edges are thiner, less contrasted and more blurred than Sobel. • Roberts: No evident difference from Sobel. • Differential: Edges less bright. • Laplace: Less interesting than the specific one.
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GNU Image Manipulation Program 463 / 653 15.5.4 Laplace 15.5.4.1 Overview Figure 15.85: Applying example for the Laplace filter (a) Original image (b) Filter Laplace applied You can find this filter through Filtres → Edge detect → Laplace. This filter detects edges in the image using Laplacian method, which produces thin, pixel wide borders. 15.5.5 Neon 15.5.5.1 Overview Figure 15.
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GNU Image Manipulation Program 464 / 653 15.5.5.2 Activating the filter You can find this filter through Filters → Edge Detect → Neon.... 15.5.5.3 Options Figure 15.87: Neon filter options Radius This option lets you determine how wide the detected edge will be. Amount This option lets you determine how strong the filter effect will be. 15.5.6 Sobel 15.5.6.1 Overview Figure 15.
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GNU Image Manipulation Program 465 / 653 15.5.6.2 Options Figure 15.89: Sobel filter options Parameters Settings • Sobel Horizontally: Renders near horizontal edges. • Sobel Vertically: Renders near vertical edges. • Keep sign of result: This option works when only one direction is selected: it gives a flat relief with bumps and hollows to the image. 15.6 Enhance Filters 15.6.1 Introduction Enhance filters are used to compensate for image imperfections.
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GNU Image Manipulation Program 466 / 653 15.6.2.2 Options Figure 15.90: Deinterlace filter options Preview When Do preview is checked, parameter setting results are interactively displayed in preview. Mode Keep odd lines and Keep even lines: One of them may render a better result. You must try both. 15.6.2.3 Example Figure 15.91: Simple applying example for the Deinterlace filter (a) Top : even lines pixels are shifted by one pixel to the (b) Keep even fields checked. Top : odd lines have been right.
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GNU Image Manipulation Program 467 / 653 15.6.3 Despeckle 15.6.3.1 Overview You can find this filter through Filters → Enhance → Despeckle. It is used to remove small defects due to dust, or scratches, on a scanned image, and also moiré effect on image scanned from a magazine. You ought to select isolated defects before applying this filter, in order to avoid unwanted changes in other areas of your image. 15.6.3.2 Options Figure 15.
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GNU Image Manipulation Program 468 / 653 15.6.4 Destripe 15.6.4.1 Overview You can find this filter through Filters → Enhance → Destripe It is used to remove vertical stripes caused by poor quality scanners. It works by adding a pattern that will interfere with the image, removing stripes if setting is good. This ‘negative’ pattern is calculated from vertical elements of the image, so don’t be surprised if you see stripes on the preview of an image that has none.
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GNU Image Manipulation Program 469 / 653 15.6.5.2 Options Figure 15.94: ‘NL Filter’ options Preview When Do preview is checked, parameter setting results are interactively displayed in preview. Parameter settings • Alpha: Meaning of this value depends on the selected option. • Radius: Controls the strength of the filter (0.33-1.00). 15.6.5.3 Operating Modes This filter can perform several distinct functions, depending on the value of the parameter alpha. Alpha trimmed mean filter. (0.0 <= alpha <= 0.
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GNU Image Manipulation Program 470 / 653 Combination use The various operating modes can be used one after the other to get the desired result. For instance to turn a monochrome dithered image into grayscale image you could try one or two passes of the smoothing filter, followed by a pass of the optimal estimation filter, then some subtle edge enhancement.
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GNU Image Manipulation Program 471 / 653 15.6.6.2 Options Figure 15.96: ‘Sharpen’ filter options Preview Parameter setting results are interactively displayed in preview. Scroll bars allow you to move around the image. Parameter setting Increase sharpness: slider and input boxes allow you to set sharpness (1-99) and you can judge result in preview. By increasing sharpness, you may increase image blemishes and also create noise in graduated color areas. 15.6.7 Unsharp Mask 15.6.7.
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GNU Image Manipulation Program 472 / 653 Tip Some imaging devices like digital cameras or scanners offer to sharpen the created images for you. We strongly recommend you disable the sharpening in this devices and use the GIMP filters instead. This way you regain the full control over the sharpening of your images. Tip To prevent color distortion while sharpening, Decompose your image to HSV and work only on Value. Then Compose the image to HSV. Go to Image/Mode and click on Decompose.
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GNU Image Manipulation Program 473 / 653 Now, we have an image with some blur we want to sharpen (black curve). We apply some more blur: the intensity variation will be more gradual (green curve). Let us substract the blurredness intensity from the intensity of the image. We get the red curve, which is more abrupt : contrast and sharpness are increased. QED. Unsharp mask has first been used in silver photography.
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GNU Image Manipulation Program 474 / 653 15.7 Generic Filters 15.7.1 Introduction Generic filters are a catch-all for filters which can’t be placed elsewhere. You can find: • The Convolution Matrix filter which lets you build custom filters. • The Dilate filter. • The Erode filter. 15.7.2 Convolution Matrix 15.7.2.1 Overview You can find this filter through Filters → Generic → Convolution Matrix Here is a mathematician’s domain. Most of filters are using convolution matrix.
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GNU Image Manipulation Program 475 / 653 15.7.2.2 Options Figure 15.100: ‘Convolution matrix’ options Matrix This is the 5x5 kernel matrix: you enter wanted values directly into boxes. Divisor: The result of previous calculation will be divided by this divisor. You will hardly use 1, which lets result unchanged, and 9 or 25 according to matrix size, which gives the average of pixel values. Offset: this value is added to the division result. This is useful if result may be negative.
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GNU Image Manipulation Program 476 / 653 Figure 15.101: Sharpen (a) (b) Figure 15.
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GNU Image Manipulation Program 477 / 653 Figure 15.103: Edge enhance (a) (b) Figure 15.
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GNU Image Manipulation Program 478 / 653 Figure 15.105: Emboss (a) 15.7.3 Dilate 15.7.3.1 Overview (b) Figure 15.106: Applying example for the Dilate filter (a) Original image (b) Filter Dilate applied You can find this filter through Filters → Generic → Dilate This filter widens and enhances dark areas of the active layer or selection. For every image pixel, it brings the pixel Value (luminosity) into line with the lowest Value (the darkest) of the 8 neighbouring pixels (3x3 matrix).
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GNU Image Manipulation Program 479 / 653 A larger dark area will dilate by one pixel in all directions: The filter was applied 3 times. On more complex images, dark areas are widenned and enhanced the same, and somewhat pixellated. Here, the filter was applied 3 times: Of course, if background is darker than foreground, it will cover the whole image. 15.7.3.2 Examples Figure 15.107: Dilate text Figure 15.108: Dilate neon effect 15.7.4 Erode 15.7.4.1 Overview Figure 15.
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GNU Image Manipulation Program 480 / 653 You can find this filter through Filters → Generic → Erode This filter widens and enhances bright areas of the active layer or selection. For every image pixel, it brings the pixel Value (luminosity) into line with the upper Value (the brightest) of the 8 neighbouring pixels (3x3 matrix). So, a bright pixel is added around bright areas. An isolated pixel on a brighter background will be deleted. A larger bright area will dilate by one pixel in all directions.
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GNU Image Manipulation Program 481 / 653 15.8.2.2 Options Figure 15.111: ‘Apply Lens’ filter options Preview Parameter setting results are interactively displayed in preview. Scroll bars allow you to move around the image. Parameter settings • Keep original surrounding: The lens seems to be put on the image. • Set surroundings to Background color: The part of the image outside the lens will have the Background color selected in Toolbox.
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GNU Image Manipulation Program 482 / 653 15.8.3.2 Options Figure 15.113: ‘Glass Tile’ filter options Preview Parameter setting results are interactively displayed in preview. Scroll bars allow you to move around the image. Parameters setting • Tile width: Sets tile width (10-50 pixels). • Tile length: Sets tile length (10-50 pixels). 15.9 Light Effects filters 15.9.1 Introduction Light Effects filters render several illumination effects of the image. 15.9.2 FlareFX 15.9.2.1 Overview Figure 15.
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GNU Image Manipulation Program 483 / 653 15.9.2.2 Options Figure 15.115: ‘FlareFX’ filter options Preview Parameter setting results are interactively displayed in preview. Scroll bars allow you to move around the image. Parameters setting • Center of FlareFX: You can set there X and Y (pixels) coordinates of glint. The coordinate origin is at upper left corner. • Show cursor: When this option is checked, a reticule appears in preview and you can move it with mouse pointer to locate center of flareX.
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GNU Image Manipulation Program 484 / 653 15.9.3.2 Options The Settings tab allows you to set manually the parameters while the Selector tab let you choose presets in a list. Preview When Auto Update Preview is checked, parameter setting results are interactively displayed in preview without modifying the image until you click on OK button. 15.9.3.3 Settings Figure 15.117: ‘GFlare’ filter options (Settings) Center Center: You can set there X and Y (pixels) coordinates of glint.
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GNU Image Manipulation Program 485 / 653 15.9.3.4 Selector Figure 15.118: ‘Gflare’ filter options (Selector) The Selector tab allows you to select a Gflare pattern, to change it and save it. New When you click on this button, you create a new Gflare pattern. Give it a name of your choice. Edit This button brings up the Gflare Editor (see below). Copy This button allows you to duplicate selected Gflare pattern. You can edit the copy without altering the original.
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GNU Image Manipulation Program 486 / 653 Figure 15.119: ‘Gflare Editor’ options (General) Glow Paint Options • Opacity: Slider and input box allows you to reduce glow opacity (0-100). • Paint Mode: You can choose between four modes: – Normal: In this mode, the glow covers the image without taking into account what is beneath. – Addition: Pixel RGB values of glow are added to RGB values of the corresponding pixels in the image. Colors get lighter and white areas may appear.
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GNU Image Manipulation Program 487 / 653 Figure 15.120: ‘Gflare Editor’ options (Glow) Gradients By clicking on the rectangular buttons, you can develop a long list of gradients. "%" gradients belong to the Editor. • Radial gradient: The selected gradient is drawn radially, from center to edge. • Angular gradient: The selected gradient develops around center, counter-clockwise, starting from three o’clock if "Rotation" parameter is set to 0.
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GNU Image Manipulation Program 488 / 653 Figure 15.121: ‘Gflare Editor’ options (Rays) Gradients The options are the same as for Glow. Parameters The first three options are the same as in Glow. Two are new: • # of spikes: This option determines the number of spikes (1-300) but also their texture.
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GNU Image Manipulation Program 489 / 653 Figure 15.122: ‘Gflare Editor’ options (Second Flares) Gradients The options are the same as for Glow. Parameters Options are the same as in Glow. Shape of Second Flares Second flares, these satellites of the main flare, may have two shapes: Circle and Polygon. You can set the Number polygon sides. The option accepts 1 side (!), not 2. Random seed and Randomize • Random Seed: The random generator will use this value as a seed to generate random numbers.
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GNU Image Manipulation Program 490 / 653 15.9.4 Lighting Effects 15.9.4.1 Overview Figure 15.123: The same image, before and after applying Lighting filter (a) Original image (b) Filter Light-Effects applied You can find this filter through Filters → Light Effectsender → Lighting Effects This filter simulates the effect you get when you light up a wall with a spot. It doesn’t produce any drop shadows and, of course, doesn’t reveal any new details in dark zones. 15.9.4.
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GNU Image Manipulation Program 491 / 653 Transparent Background Transparent Background: Makes destination image transparent when bumpmap height is zero (height is zero in black areas of the bumpmapped image). Create New Image Create New Image: Creates a new image when applying filter. High Quality Preview High Quality Preview: For quick CPU... Light Figure 15.125: ‘Light’ Options of the Lighting filter In this tab, you can set light parameters. With Light 1, 2,...
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GNU Image Manipulation Program 492 / 653 These options don’t concern light itself, but light reflected by objects. Small spheres, on both ends of the input boxes, represent the action of every option, from its minimum (on the left) to its maximum (on the right). Help pop ups are more useful. Glowing With these option, you can set the amount of original color to show where no direct light falls. Bright With this option, you can set the intensity of original color when hit directly by a light source.
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GNU Image Manipulation Program 493 / 653 15.9.5 Sparkle 15.9.5.1 Overview Figure 15.129: Applying example for the Sparkle filter (a) Original image (b) Filter Sparkle applied You can find this filter in the image menu through Filters → Light Effects → Sparkle This filter adds sparkles to your image. It uses the lightest points according to a threshold you have determined. It is difficult to foresee where sparkles will appear. But you can put white points on your image where you want sparkles to be.
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GNU Image Manipulation Program 494 / 653 Luminosity Threshold The higher the threshold, the more areas are concerned by sparkling (0.0-0.1). Flare Intensity When this value increases, the central spot and rays widen (0.0-1.0). Spike Length This is ray length (1-100). When you reduce it, small spikes decrease first. Spike Points Number of starting points for spikes (0-16). It’s the number of big spikes. There is the same number of small spikes. When number is odd, small spikes are opposite the big ones.
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GNU Image Manipulation Program 495 / 653 15.9.6.2 Parameter Settings Figure 15.132: ‘Supernova’ filter options Preview Parameter setting results are interactively displayed in preview. Scroll bars allow you to move around the image. Center of SuperNova • You can use input boxes to set horizontal (X) and vertical (Y) coordinates of SuperNova center. You can also click and drag the SuperNova center in preview.
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GNU Image Manipulation Program 496 / 653 15.10.2 Blinds 15.10.2.1 Overview Figure 15.133: Applying example for the Blinds filter (a) Original image (b) Filter Blinds applied You can find this filter through Filters → Distort → Blinds. It generates a blind effect with horizontal or vertical battens. You can lift or close these battens, but not lift the whole blind up. 15.10.2.2 Options Figure 15.
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GNU Image Manipulation Program 497 / 653 15.10.3 Curve Bend 15.10.3.1 Overview Figure 15.135: Applying example for the Curve Bend filter (a) Original image (b) Filter Curve Bend applied You can find this filter through Filters → Distorts → Curve Bend. This filter allows you to create a curve that will be used to distort the active layer or selection. The distortion is applied gradually from an image or selection border to the other. 15.10.3.2 Options Figure 15.
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GNU Image Manipulation Program 498 / 653 Preview The preview displays changes to image or selection without modifying the image until you press OK. Preview Once This button allows you to update the preview each time you need it. Automatic Preview With this option, preview is changed in real time. This needs much calculation and may lengthen work. It is particularly evident when using "Rotation". Options Rotate There, you can set the application angle of filter (0-360 counter-clockwise).
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GNU Image Manipulation Program 499 / 653 15.10.4 Emboss 15.10.4.1 Overview Figure 15.137: Applying example for the Emboss filter (a) Original image (b) Filter Emboss applied You can find this filter through Filters → Distorts → Emboss. You can use it only with RGB images. If your image is grayscale, it will be grayed out in the menu. It stamps and carves the active layer or selection, giving it relief with bumps and hollows. Bright areas are raised and dark ones are carved.
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GNU Image Manipulation Program 500 / 653 Functions Bumpmap: Relief is smooth and colors are preserved. Emboss: It turns your image to grayscale and relief is more marked, looking like metal. Azimuth Azimuth: This is about lighting according to the points of the compass (0 - 360). If you suppose South is at the top of your image, then East (0) is on the left. Increasing value goes counter-clockwise.
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GNU Image Manipulation Program 501 / 653 Figure 15.140: ‘IWarp’ filter options (Settings tab) The Settings tab allows you to set parameters which will affect the preview you are working on. So, you can apply different deform modes to different parts of the preview. Preview Here, the Preview is your work space: You click on the Preview and drag mouse pointer. The underlying part of image will be deformed according to the settings you have chosen. If your work is not convenient, press the Reset button.
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GNU Image Manipulation Program 502 / 653 This tab allows to generate several intermediate images between the original image and the final deformation of this image. You can play this animation thanks to the plugin Playback. Number of Frames That’s the number of images in your animation (2-100). These frames are stored as layers attached to your image. Use the XCF format when saving it. Reverse This option plays the animation backwards. Ping-Pong When the animation ends one way, it goes backwards. 15.10.
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GNU Image Manipulation Program 503 / 653 Preview All your setting changes will appear in the Preview without affecting the image until you click on OK. Note that the preview displays the whole image, even if the final result will concern a selection. Don’t keep Do Preview checked if your computer is too much slow. Options Antialiasing Antialiasing: This option reduces the stepped aspect that may have borders.
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GNU Image Manipulation Program 504 / 653 15.10.7.2 Options Figure 15.144: Options Curl Location You have there four radio buttons to select the corner you want raise. The Preview is redundant and doesn’t respond to other options. Curl Orientation Horizontal and Vertical refer to the border you want raise. Shadow under curl This is the shadow inside the cornet. Use current gradient instead of FG/FB-color This color refers to the outer face of the cornet.
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GNU Image Manipulation Program 505 / 653 You can find this filter through Filters → Distorts → Polar Coords. It gives a circular or a rectangular representation of your image with all the possible intermediates between both. 15.10.8.2 Options Figure 15.146: ‘Polar Coords’ filter options Preview The result of your settings will appear in the Preview without affecting the image until you click on OK.
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GNU Image Manipulation Program 506 / 653 Figure 15.148: With two horizontal bars 15.10.9 Ripple 15.10.9.1 Overview You can find this filter through Filters → Distotrts → Ripple. It displaces the pixels of the active layer or selection to waves or ripples reminding a reflection on disturbed water. 15.10.9.2 Options Preview The result of your settings will appear in the Preview without affecting the image until you click on OK.
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GNU Image Manipulation Program 507 / 653 15.10.10 Shift 15.10.10.1 Overview Figure 15.149: Example for the Shift filter (a) Original image (b) Filter Shift applied You can find this filter through Filters → Distorts → Sift. It shifts all pixel rows, horizontally or vertically, in the current layer or selection, on a random distance and within determined limits. 15.10.10.2 Options Figure 15.
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GNU Image Manipulation Program 508 / 653 15.10.11 Newsprint 15.10.11.1 Overview Figure 15.151: Applying example for the Newsprint filter (a) Original image (b) Filter Newsprint applied You can find this filter through Filters → Distorts → Newsprint. This filter halftones the image using a clustered-dot dither. Halftoning is the process of rendering an image with multiple levels of grey or colour (i.e.
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GNU Image Manipulation Program 509 / 653 15.10.11.2 Options Figure 15.152: ‘Newsprint’ filter options Preview All your setting changes will appear in the Preview without affecting the image until you click on OK. Note that the preview displays the whole image, even if the final result will concern a selection. Don’t keep Do Preview checked if your computer is too much slow. Resolution This group controls the cell size, either by setting the input and output resolutions, or directly.
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GNU Image Manipulation Program 510 / 653 Oversample Oversample: Number of subpixels to sample to produce each output pixel. Set to 1 to disable this feature. Warning: large numbers here will lead to very long filter runtimes! 15.10.11.3 Example Figure 15.153: Example for Newsprint An example from plug-in author 15.10.12 Video 15.10.12.1 Overview Figure 15.154: Applying example for the ‘Video’ filter (a) Original image You can find this filter through Filters → Distorts → Sift.
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GNU Image Manipulation Program 511 / 653 15.10.12.2 Options Figure 15.155: ‘Video’ filter options Preview This preview is unusual: Changes appear always on the same image which is not yours. RGB Pattern Type It would be rather difficult to describe what each pattern will render. It’s best to see what they render in the Preview. Additive Set whether the function adds the result to the original image. Rotated Rotate the result by 90. 15.10.13 Value Propagate 15.10.13.
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GNU Image Manipulation Program 512 / 653 Propagate Mode The examples will be about the following image (zoom x8): Figure 15.156: Original image • More White: Pixels will be propagated from upper Value pixels towards lower Value pixels. So bright areas will enlarge. Figure 15.157: More White Bright pixels have been propagated to dark pixels in the four directions : top, bottom, right and left. Filter applied several times to increase effect.
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GNU Image Manipulation Program 513 / 653 Figure 15.159: To bottom only The same as above with To bottom direction only checked. • Middle Value to Peaks: On a border between the selected thresholds, the average of both values is propagated. Figure 15.160: Middle Value to Peaks Middelverdi til spissane (a) A thin border with a transitional color has been added to objets. It is not visible around objects with smoothed borders. (b) Green area zoomed x800. A thin border (one pixel wide) has been added.
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GNU Image Manipulation Program 514 / 653 Figure 15.162: Only Foreground In this example, the foreground color in Toolbox is that of the green object. After applying filter several times, the green area is clearly enlarged. • Only Background: Only areas with the Background color will propagate. • More Opaque and More Transparent: These commands work like More White and More Black. Opaque (transparent) areas will be propagated over less opaque (transparent) areas.
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GNU Image Manipulation Program 515 / 653 15.10.14 Waves 15.10.14.1 Overview Figure 15.164: Example for the Waves filter (a) Original image (b) Filter Waves applied You can find this filter through Filters → Distorts → Waves. With this filter you get the same effect as a stone thrown in a quiet pond, giving concentric waves. 15.10.14.2 Options Figure 15.165: ‘Waves’ filter options Preview All your setting changes will appear in the Preview without affecting the image until you click on OK.
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GNU Image Manipulation Program 516 / 653 Reflective Reflective: Waves bounce on sides and interfere with the arriving ones. Amplitude Amplitude: Varies the height of waves. Phase Phase: This command shifts the top of waves. Wavelength Wavelength: Varies the distance between the top of waves. 15.10.15 Whirl and Pinch 15.10.15.1 Overview Figure 15.
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GNU Image Manipulation Program 517 / 653 Figure 15.167: Illustration (a) Original 15.10.15.2 (b) Whirled (c) Pinched Parameter Settings Figure 15.168: ‘Whirl and Pinch’ filter options Preview Changes to parameters are immediately displayed into the Preview. The whirlpool is focused around the center of the current layer or selection. Whirl Angle Whirl Angle: Clockwise or counter clockwise (-360 to +360). Controls how many degrees the affected part of the image is rotated.
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GNU Image Manipulation Program 518 / 653 15.10.16 Wind 15.10.16.1 Overview Figure 15.169: ‘Wind’ filter example (a) Original image (b) Filter Wind applied You can find this filter through Filters → Distorts → Wind. The Wind filter can be used to create motion blur, but it can also be used as a general distort filter. What is characteristic about this filter is that it will render thin black or white lines.
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GNU Image Manipulation Program 519 / 653 You can only set the wind in two directions, either Left or Right. However, you can control which edge the wind will come from using the values Leading, Trailing or Both. Because Trailing will produce a black wind, it creates a less convincing motion blur than Leading, which will produce white wind. The following illustrations are based on this image: Preview All your setting changes will appear in the Preview without affecting the image until you click on OK.
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GNU Image Manipulation Program 520 / 653 Threshold Threshold: The threshold to detect borders. The higher it is, the fewer borders will be detected. Strength Strength: Higher values increase the strength of the effect. 15.11 Artistic filters 15.11.1 Introduction Artistic filters create artistic effects like cubism, oil painting, canvas... 15.11.2 Apply Canvas 15.11.2.1 Overview Figure 15.
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GNU Image Manipulation Program 521 / 653 15.11.2.2 Options Figure 15.172: ‘Apply Canvas’ options Preview Your changes are displayed in this preview before being applied to your image. Direction Direction sets the starting direction of the canvas render. You can also consider that this option gives you the position of the light source which lightens the canvas. Depth The Depth slider controls the apparent depth of the rendered canvas effect from 1 (very flat) to 50 (very deep). 15.11.3 Cartoon 15.11.
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GNU Image Manipulation Program 522 / 653 15.11.3.2 Options Figure 15.174: ‘Cartoon’ filter options Mask radius This parameter controls the size of areas the filter works with. Large values result in very thick black areas and much less detail in the resulting image. Small values result in more subtle pen strokes and more details preserved. Percent black This parameter controls the amount of black color added to the image.
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GNU Image Manipulation Program 523 / 653 Tip If setting possibilities of this filter are not enough for you, see GIMPressionist filter which offers more options. 15.11.4.2 Options Figure 15.176: ‘Cubism’ filter options Tile Size This variable determines the size, in pixels, of the squares to be used. This is, in effect, the size of the little squares of tissue paper used in generating the new image.
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GNU Image Manipulation Program 524 / 653 Figure 15.178: The option is not checked The option is not checked. On the left is no Alpha: background is black. On the right is Alpha: background is transparent black. Figure 15.179: The option is checked The option is checked. On the left, no Alpha: background is blue. On the right, with an Alpha channel, background is transparent blue.
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GNU Image Manipulation Program 525 / 653 15.11.5 GIMPressionist 15.11.5.1 Overview Figure 15.180: The same image, before and after applying GIMPressionist (a) Original image (b) Filter GIMPressionist applied You can find this filter via the image menu under Filters → Artistic → GIMPressionist It’s the king of Artistic filters. It can do what Cubism and Apply Canvas do and much more. It gives your image the look of a painting.
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GNU Image Manipulation Program 526 / 653 GIMPressionist has a lot of parameters. When combined, they give an astronomical number of possibilities. So, it is important, when an interesting preset has been found, to save it and also to send it to the plugin author if exceptional. Per contra, the intricacy of all these parameters makes difficult understanding and foreseeing how each one works. • Save Current: Save current parameters.
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GNU Image Manipulation Program 527 / 653 Figure 15.183: ‘Brush’ tab options "Brush" is a general term for any material used to paint. A list of brushes is available with a Preview for the selected one. Gamma Changes the gamma (luminosity) of the selected brush. The gamma correction brightens or darkens midtones. Select You can also use a brush pattern you have created by selecting its image (arrow button on the Select line).
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GNU Image Manipulation Program 528 / 653 Orientation Specifies the direction of the brush strokes. • Value : Let the Value (luminosity) of the region determine the direction of the stroke. • Radius : The distance from the center of the image determines the direction of the stroke. • Random : Select a random direction for each stroke. • Radial : Let the direction from the center determine the direction of the stroke. • Flowing : Not a direction question here: the strokes follow a "flowing" pattern.
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GNU Image Manipulation Program 529 / 653 In this tab you can set how strokes will be distributed. Placement In the preview of the Orientation Map Editor, all small arrows look like a flow around objects. Inside this flow, strokes may be placed in two different ways: • Randomly: Places strokes ramdomly. This produces a more realistic paint. • Evenly: Strokes are evenly distributed across the image. Stroke Density The greater the density the closer the strokes.
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GNU Image Manipulation Program 530 / 653 • Solid: By clicking on the color dwell you can select a solid colored background. • Transparent: Use a transparent background. Only the painted strokes will be visible. This option is available only if your image has an Alpha channel. Paint Edges If it is disabled, a thin border will not be painted around the outside border of the image. Tileable If checked, the resulting image will be seamlessly tileable.
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GNU Image Manipulation Program 531 / 653 Tip With the scroll bar on the right of the Vectors panel, you can set the image brightness. This can be very useful if the image is very dark/bright and you can’t see vectors well. Preview This Preview gives you an idea of the action of the various vectors. The slider on the right border lets you change the luminosity of this preview. Type You have there some types to arrange the brush strokes within the selected vector domain.
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GNU Image Manipulation Program 532 / 653 Smvectors In this window you can place your vectors. By clicking on the Add button, you add a vector at the center of the window, whereas clicking with the mouse Middle Button puts it where you click. Vectors are red when selected, and gray when they are not, with a white point at tip. Clicking with the mouse Left Button displaces the selected vector to the clicked point. Clicking on the mouse Right Button, has no evident action.
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GNU Image Manipulation Program 533 / 653 15.11.8.2 Options Figure 15.192: ‘Oilify’ filter options Mask Size Mask Size selects the size of the brush mask used to paint the oily render. Larger values here produce an oilier render. Use Intensity Algorithm Use Intensity Algorithm changes the mode of operation to help preserve detail and coloring. 15.11.9 Photocopy 15.11.9.1 Overview Figure 15.
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GNU Image Manipulation Program 534 / 653 15.11.9.2 Starting filter You can find this filter from the image menu through Filters → Artistic → Photocopy. 15.11.9.3 Options Figure 15.194: ‘Photocopy’ filter options Mask radius This parameter controls the size of the pixel neighbourhood over which the average intensity is computed and then compared to each pixel in the neighborhood to decide whether or not to darken it.
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GNU Image Manipulation Program 535 / 653 15.11.10 Soft Glow 15.11.10.1 Overview Figure 15.195: The same image, before and after applying SoftGlow filter (a) Original image (b) Filter SoftGlow applied This filter lights the image with a soft glow. Soft Glow produces this effect by making brigth areas of the image brighter. 15.11.10.2 Starting filter You can find this filer in the Image menu: Filters → Atistic → Soft Glow. 15.11.10.3 Options Figure 15.
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GNU Image Manipulation Program 536 / 653 15.12 Map Filters 15.12.1 Introduction Map filters use an object named map to modify an image: you map the image to the object. So, you can create 3D effects by mapping your image to another previously embossed image ("Bumpmap" Filter) or to a sphere ("Map Object" filter). You can also map a part of the image elsewhere into the same image ("Illusion" and "Make Seamless" filters), bend a text along a curve ("Displace" filter)... 15.12.2 Bump Map 15.12.2.
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GNU Image Manipulation Program 537 / 653 Bump Map This drop-down list allows you to select the image that will be used as a map for bumpmapping. This list contains images that are present on your screen when you launch the filter. Images opened after starting filter are not present in this list. Map Type This option allows you to define the method that will be used when creating the map image: • Linear: bump height is a direct function of luminosity.
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GNU Image Manipulation Program 538 / 653 This filter uses a ‘displace-map’ to displace corresponding pixels of the image. This filter displaces the content of the specified drawable (active layer or selection) by the amounts specified in X and Y Displacement multiplied by the intensity of the corresponding pixel in the ’displace map’ drawables. Both X and Y displace maps should be gray-scale images and have the same size as the drawable . This filter allows interesting distortion effects. 15.12.3.
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GNU Image Manipulation Program 539 / 653 On Edges These options allows you to set displacement behaviour on active layer or selection edges: • Wrap: With this option, what disappears on one edge reappears on the opposite edge. • Smear: With this option, pixels vacated by displacement are replaced with pixels stretched from the adjacent part of the image. • Black: With this option, pixels vacated by deplacement are replaced with black. 15.12.3.3 Using gradient to bend a text Follow following steps: 1.
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GNU Image Manipulation Program 540 / 653 15.12.3.4 Displacement Calculation The following section will show you how to calculate the amount of displacement, if you are interested in these details. If you don’t want to know it, you can safely omit this section. The overview example showed the X displacement using a coefficient of 30.0: 19, 8, 4, or 15 pixels, depending on the grey level of the displacement map’s color. Why just these amounts? That’s easy: 30.0 * (I - 127.5) / 127.
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GNU Image Manipulation Program 541 / 653 15.12.4.2 Options Figure 15.202: ‘Fractal trace’ filter options M ANDELBROT PARAMETERS X1, X2, Y1, Y2, Depth These parameters are similar to X/YMIN, X/YMAX and ITER parameters of the Fractal Explorer filter. They allow you to vary fractal spreading and detail depth. Outside type Mapping image to fractal may reveal empty areas.
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GNU Image Manipulation Program 542 / 653 Divisions That’s the number of copies you want to apply to image. This value varies from -32 to 64. Negative values invert kaleidoscope rotation. Modes You have two arrangement modes for copies in image: Figure 15.204: From left to right: original image, mode 1, mode 2, with Divisions=4 (a) 15.12.6 Make Seamless 15.12.6.1 Overview (b) (c) Figure 15.205: An example of Make Seamless.
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GNU Image Manipulation Program 543 / 653 15.12.7 Map Object 15.12.7.1 Overview Figure 15.206: The ‘Map Object’ filter applied to a photograph (a) Original (b) Map Object appliedAprès application du filtre This filter maps a picture to an object (plane, sphere, box or cylinder). You can find this filter through Filters → Map → Map Object. 15.12.7.2 15.12.7.2.
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GNU Image Manipulation Program 544 / 653 15.12.7.2.2 General Options tab Figure 15.207: ‘Map Object’ general options tab Map to This drop-down list allows you to select the object the image will be mapped on. It can be a Plane, a Sphere, a Box or a Cylinder. Transparent background This option makes image transparent around the object. If not set, the background is filled with the current background color.
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GNU Image Manipulation Program 545 / 653 15.12.7.2.3 Light tab Figure 15.208: ‘Light’ tab options Light Settings • Lightsource type: In this dropdown list, you can select among Point light, Directionnal light and No light. • Lightsource color: Press this button to open the Color Selector dialog. Position If ‘Point light’ is selected, you can control there light source Position (the blue point), according to X, Y and Z coordinates.
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GNU Image Manipulation Program 546 / 653 15.12.7.2.4 Material tab Figure 15.209: ‘Material’ tab options Intensity Levels • Ambient: Amount of color to show where no light falls directly. • Diffuse: Intensity of original color when lit by a light source. Reflectivity • Diffusion: Higher values make object reflect more light (looks brighter). • Specular: Controls how intense the highlights will be. • Highlight: Higher values make the highlights more focused.
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GNU Image Manipulation Program 547 / 653 15.12.7.2.5 Orientation tab Figure 15.210: ‘Orientation’ tab options Position These three sliders and their input boxes allows you to vary object position in image, according to the X, Y, Z coordinates of the object upper left corner. Rotation These three sliders make the object rotate around X, Y, Z axes respectively. 15.12.7.2.6 Box tab This tab appears only when you select the Box object.
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GNU Image Manipulation Program 548 / 653 Figure 15.211: ‘Box’ tab options Match Images to Box Faces This function name is self explanatory: you can select an image for every face of the box. These images must be present on your screen when you call the Map Object filter. Scale These X, Y, Z three sliders allow you to change the size of every X, Y, Z dimension of the box. 15.12.7.2.7 Cylinder tab This tab appears only when you select the Cylinder object.
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GNU Image Manipulation Program 549 / 653 Figure 15.212: ‘Cylinder’ tab options Images for the Cap Faces The name of this option is self-explanatory. Images must be present on your screen when you call the Map Object filter. Size • Radius : This slider and its input boxes let you control the Cylinder diameter. Unfortunately, this setting works on the image mapped onto the cylinder and resamples this image to adapt it to the new cylinder size.
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GNU Image Manipulation Program 550 / 653 15.12.8 Paper Tile 15.12.8.1 Overview Figure 15.213: From left to right: original image, after applying ‘Paper Tile’ filter (division = 3) (a) Original image (b) Filter Papertile applied This filter cuts the image (active layer or selection) into several pieces, with square form, and then slides them so that they, more or less, overlap or move apart. They can go out image borders a little. 15.12.8.
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GNU Image Manipulation Program 551 / 653 • Max% is the maximum displacement percentage against the side size of squares. • Wrap around : As tiles move, some can go out image borders. If this option is checked, what goes out on one side goes in on the opposite side. Fractional Pixels Because of image cutting, original pixels can persist. There are three ways treating them: • Background: Remaining pixels will be replaced with the background type defined in the following section.
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GNU Image Manipulation Program 552 / 653 15.12.9.3 Options Figure 15.216: ‘Small Tiles’ filter options Number of Segments n**2 means ‘the image into n to the power of two tiles’, where ‘n’ is the number you set with the slider or its input box. n = 3 will make nine tiles in the image. Opacity With this slider and its input box, you can set the opacity of the resulting image. This option is valid only if your image has an Alpha channel.
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GNU Image Manipulation Program 553 / 653 15.12.10.2 Options Figure 15.218: ‘Tile’ filter options T ILE TO NEW SIZE Width/Height Input boxes and their arrow-heads allow you to enter the dimensions for the new image. Both directions are . You can make them independent by breaking this chain. You can choose a unit else linked by default with a chain than pixel by clicking on the drop-down list button. The new image must be bigger than the original one . Else, you will get an image sample only.
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GNU Image Manipulation Program 554 / 653 Figure 15.221: With a complex gradient: And a complex gradient, such as the Solid Noise filter can create, gives a swirl effect. This filter offers the possibility of masking a part of the image to protect it against filter action. 15.12.11.2 Options Figure 15.222: Warp filter options BASIC O PTIONS Step Size ‘Step’ is displacement distance for every filter iteration. A 10 value is necessary to get a one pixel displacement.
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GNU Image Manipulation Program 555 / 653 Dither Size Once all pixels displaced, this option scatters them randomly, giving grain to the image. The higher this value (0.00-100.00), the thinner the grain. Figure 15.223: With a 3.00 dither size: Rotation Angle This option sets displacement angle of pixels according to the slope direction of gradient. Previous examples have been created with a vertical gradient and a 90 angle: so, pixels were displaced horizontally and nothing went out of the image borders.
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GNU Image Manipulation Program 556 / 653 Figure 15.226: Gradient map example From left to right: original image, displacement map, after applying Warp filter with a Gradient Scale map. Gradient is oblique, from top left to right bottom. The part of the image corresponding to the gradient is moved obliquely, 90 rotated (Rotation Angle 90 in Advanced options). The Vector Map Figure 15.
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GNU Image Manipulation Program 557 / 653 You can find this filter through Filters → Map → Van Gogh (LIC). ‘LIC’ stands for Line Integral Convolution, a mathematical method. The plug-in author uses mathematical terms to name his options... This filter is used to apply a directional blur to an image, or to create textures. It could be called ‘Astigmatism’ as it blurs certain directions in the image. It uses a blur map. Unlike other maps, this filter doesn’t use grey levels of this blur map.
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GNU Image Manipulation Program 558 / 653 Figure 15.231: Blurring with a square gradient map The gradient map is divided into four gradient triangles: each of them has its own gradient direction. In every area of the image corresponding to gradient triangles, only lines with the same direction as gradient are blurred. Figure 15.232: Texture example The With white noise option is checked. Others are default. With a vertical gradient map, texture fibres are going horizontally.
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GNU Image Manipulation Program 559 / 653 Figure 15.235: Filter Length example on texture On the left: a texture with Noise Length=3. On the right, the same texture with Noise Length=24. Noise Magnitude This options controls the amount and size of White Noise. Low values produce finely grained surfaces. High values produce coarse-grained textures. Figure 15.
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GNU Image Manipulation Program 560 / 653 15.13 Rendering Filters 15.13.1 Introduction Most GIMP filters work on a layer by transforming its content, but the filters in the ‘Render’ group are a bit different. They create patterns from scratch, in most cases obliterating anything that was previously in the layer. Some create random or noisy patterns, others regular of fractal patterns, and one (Gfig) is a general-purpose (but rather limited) vector graphics tool. 15.13.2 Plasma 15.13.2.
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GNU Image Manipulation Program 561 / 653 15.13.2.2 Options Figure 15.240: ‘Plasma’ filter options Random Seed Random Seed controls the randomization element. The Randomize check-button will set the seed using the hardware clock of the computer. There is no reason to use anything else unless you want to be able to repeat the exact same pattern of randomization on a later occasion. Turbulence This parameter controls the complexity of the plasma.
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GNU Image Manipulation Program 562 / 653 15.13.3.2 Options Figure 15.242: ‘Solid Noise’ filter options Random Seed Random Seed controls random behaviour of the filter. If the same random seed in the same situation is used, the filter produces exactly the same results. A different random seed produces different results. Random seed can be entered manually or generated randomly by pressing New Seed button.
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GNU Image Manipulation Program 563 / 653 15.13.4 Flame 15.13.4.1 Overview Figure 15.243: Example of a rendered Flame. (a) (b) Filter Flame applied You can find this filter through Filters → Render → Nature → Flame With the Flame filter, you can create stunning, randomly generated fractal patterns. You can’t control the fractals as you can with the Ifs Compose filter, but you can steer the random generator in a certain direction, and choose from variations of a theme you like.
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GNU Image Manipulation Program 564 / 653 15.13.4.2 Options Figure 15.244: ‘Flame’ filter options Edit Figure 15.245: The Edit Flame dialog Pressing this button brings up the Edit dialog. The dialog shows nine different windows. The pattern displayed in the center is the current pattern, and the eight windows surrounding it are random variations of that pattern. Clicking on the central image creates eight new variations, which can be adjusted with the Speed control.
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GNU Image Manipulation Program 565 / 653 on it, and it instantly replaces the image in the middle. To pick a certain character or theme for the variations, you can choose from nine different themes in the Variations menu. You can also use Randomize, which replaces the current pattern with a new random pattern. Open This button brings up a file selector that allows you to open a previously saved Flame settings file.
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GNU Image Manipulation Program 566 / 653 15.13.5.1 Overview Figure 15.246: Applying example for the IFS Compose filter Filter IFS Fractal applied You can find this filter through Filters → Render → Nature → IFS fractal This fractal-based plug-in is truly wonderful! With this versatile instrument, you can create amazingly naturalistic organic shapes, like leaves, flowers, branches, or even whole trees. (‘IFS’ stands for ‘Iterated Function System ’.
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GNU Image Manipulation Program 567 / 653 Spatial Transformation Gives you information on the active fractal, and allows you to type a value instead of changing it manually. Changing parameters with the mouse isn’t very accurate, so this is a useful option when you need to be exact. Color transformation Figure 15.
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GNU Image Manipulation Program 568 / 653 Figure 15.248: Tutorial Step 2 Start by rotating triangles 2 and 3, trying to keep them nearly the same size. 3. To make the leaf symmetrical, adjust the bottom triangle to point slightly to the left, and the right triangle to point slightly to the right. 4. Press New to add a component to the composition. This is going to be the stem of the leaf, so we need to make it long and thin. Press Stretch, and drag to stretch the new triangle.
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GNU Image Manipulation Program 569 / 653 Figure 15.250: Tutorial Step 4 Enlarge component 1, arrange the other components appropriately, then select all, scale and rotate. 6. The final step is to adjust color. Click on the Color Transformation tab, and choose a different color for each fractal. To do this, check Simple and press the right color square. A color circle appears, where you can click or select to choose a color. Figure 15.
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GNU Image Manipulation Program 570 / 653 15.13.6.1 Overview Figure 15.252: Two examples of diffraction patterns. (a) (b) You can find this filter through Filters → Render → Patterns → Diffraction Patterns. This filter lets you make diffraction or wave interference textures. You can change the Frequency, Contours and Sharp Edges for each of the RGB channels. You can also set Brightness, Scattering and Polarization of the texture.
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GNU Image Manipulation Program 571 / 653 15.13.7.2 Starting filter You can find this filter from the image menu through Filters → Render → Pattern → CML Explorer 15.13.7.3 Options General Options Figure 15.254: ‘CML Explorer’ filter options(Hue) Filter options are distributed among Hue,Saturation, Value, Advanced, others and Misc.ops tabs. Some more options are available. They will be described in following section.
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GNU Image Manipulation Program 572 / 653 Composition Here, these options concern Hue. You can select: None, Max(x, -), Max(x+d, -), Max(x-d, -), Min(x, -), Min(x+d, -), Min(x-d, -), Max(x+d, -), (x < 0,5), Max(x+d, -), (0,5 < x), Max(x-d, -), (x < 0,5), Max(x-d, -), (0,5 < x), Min(x+d, -), (x < 0,5), Min(x+d, -), (0,5 < x), Min(x-d, -), (x < 0,5) and Min(x-d, -), (0,5 < x). A book could be filled with results of all these functions. Please, experiment! Misc.
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GNU Image Manipulation Program 573 / 653 Figure 15.256: ‘CML Explorer’ filter options(Saturation) In this tab, you can set how Saturation component of the HSV color model will be used in pattern calculation. These options are similar to Hue tab options. Value tab Figure 15.257: ‘CML Explorer’ filter options (Value) In this tab, you can set how the Value (Luminosity) component of the HSV color model will be used in pattern calculation. These options are similar to Hue tab options.
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GNU Image Manipulation Program 574 / 653 Figure 15.258: ‘CML Explorer’ filter options (Advanced) These tab settings apply to the three HSV channels. Channel Sensitivity // TODO Mutation rate // TODO Mutation distance //TODO Others tab Figure 15.259: ‘CML Explorer’ filter options (Others) In this tab, you can find various parameters about image display and random intervention.
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GNU Image Manipulation Program 575 / 653 Figure 15.260: ‘CML Explorer’ filter options (Misc.ops) In this tab you can find various options about copy and loading. Copy settings These options allow you to transfer information from one of the HSV channel to another one. Selective load setting With the Open button of this filter, you can load previously loaded settings. If you don’t want to load all of them, you can select a source and a destination channel here. 15.13.8 Grid 15.13.8.
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GNU Image Manipulation Program 576 / 653 It renders a Cartesian grid in the active layer, on top of the existing contents. The width, spacing, offsets, and colors of the grid lines can all be set by the user. By default, the lines are with the GIMP’s foreground color. (Note: this plugin was used to create demonstration images for many of the other plugins.) Tip If you set the grid line widths to 0, then only the intersections will be drawn, as plus-marks. 15.13.8.2 Options Figure 15.
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GNU Image Manipulation Program 577 / 653 15.13.9 Maze 15.13.9.1 Overview Figure 15.263: An example of a rendered maze. Filter Maze applied You can find this filter in the image menu through Filters → Render → Pattern → Maze This filter generates a random black and white maze pattern. The result completely overwrites the previous contents of the active layer. A typical example is shown below. Can you find the route from the center to the edge? 15.13.9.2 Options Figure 15.
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GNU Image Manipulation Program 578 / 653 Seed You can specify a seed for the random number generator, or ask the program to generate one for you. Unless you need to later reproduce exactly the same maze, you might as well have the program do it. Algorithm You can choose between two algorithms for maze, Depth First and Prim’s Algorithm. Only a computer scientist can tell the difference between them. 15.13.10 Jigsaw 15.13.10.
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GNU Image Manipulation Program 579 / 653 15.13.10.2 Options Figure 15.266: ‘Jigsaw’ filter options Number of Tiles How many tiles across the image is, horizontally and vertically. Bevel Width The Bevel width slider controls the slope of the edges of the puzzle pieces (a hard wooden puzzle would require a low Bevel width value, and a soft cardboard puzzle would require a higher value). Highlight The Highlight slider controls the strength of the highlight that will appear on the edges of each piece.
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GNU Image Manipulation Program 580 / 653 The Qbist filter generates random textures. A starting texture is displayed in the middle square, and different variations surround it. If you like one of the alternative textures, click on it. The chosen texture now turns up in the middle, and variations on that specific theme are displayed around it. When you have found the texture you want, click on it and then click OK.
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GNU Image Manipulation Program 581 / 653 15.13.12 Checkerboard 15.13.12.1 Overview Figure 15.270: Example for the Checkerboard filter (a) Filter Checkerboard applied (b) Psychobilly Checkerboard This filter creates a checkerboard pattern replacing the current layer content. Colors used for pattern are current Fore- and Back ground colors of toolbox. 15.13.12.2 Starting filter You can find this filter in the image menu through Filters → Render → Pattern → Checkerboard 15.13.12.
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GNU Image Manipulation Program 582 / 653 15.13.13 Sinus 15.13.13.1 Overview Figure 15.272: Applying example for the Sinus filter Filter Sinus applied You can find this filter from the image menu through Filters → Render → Pattern → Sinus The Sinus filter lets you make sinusoidally based textures, which look rather like watered silk or maybe plywood. This plug-in works by using two different colors that you can define in the Colors tab.
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GNU Image Manipulation Program 583 / 653 15.13.13.2 Options Figure 15.273: ‘Sinus’ filter options (Settings) Settings tab X and Y Scales A low X/Y value will maximize the horizontal/vertical stretch of the texture, whereas a high value will compress it. Complexity This controls how the two colors interact with each other (the amount of interplay or repetition). Random Seed Random Seed controls the random behaviour of the filter.
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GNU Image Manipulation Program 584 / 653 Colors Here, you set the two colors that make up your texture. You can use Black and white or the foreground/background colors in the toolbox, or you can choose a color with the color icons. The Alpha Channels sliders allow you to assign an opacity to each of the colors. (If the layer you are working on does not have an alpha channel, they will be grayed out.) Blend settings Figure 15.
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GNU Image Manipulation Program 585 / 653 15.13.14.2 Starting filter You can find this filter through Filters → Render → Nature → Fractal Explorer 15.13.14.3 Options Figure 15.277: ‘Parameters’ options for Fractal Explorer filter Preview domain Uncheck the Real time preview only if your computer is slow. In this case, you can update preview by clicking on the Redraw button. By clicking-dragging mouse pointer on preview, you can draw a rectangle delimiting an area which will be zoomed.
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GNU Image Manipulation Program 586 / 653 Figure 15.278: Color tab options This tab contains options for fractal color setting. Color number This slider and its input boxes allow you to set the number of colors for the fractal, between 2 and 8192. A palette of these colors is displayed at the bottom of the tab. Actually, that’s a gradient between colors in fractal: you can change colors with ‘Color intensity ’ and ‘Color function ’ options.
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GNU Image Manipulation Program 587 / 653 • Apply active gradient to final image : used colors will be that of active gradient. You should be able to select another gradient by clicking on the gradient source button. Fractals tab Figure 15.280: ‘Fractal tab’ options This tab contains a big list of fractals with their parameters, that you can use as a model: only click on the wanted one. The Refresh allows you to update the list if you have saved your work, without needing to re-start Gimp.
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GNU Image Manipulation Program 588 / 653 15.13.15 Gfig 15.13.15.1 Overview Figure 15.281: The same image, before and after using Gfig (a) Original image (b) Filter Gfig applied This filter is a tool: You can create geometrical figures to add them to the image. It is very complex. I hope this paper will help you. When using this filter, elements inserted in the image will be placed in a new layer. So the image will not be modified, all modifications occuring in this layer. 15.13.15.
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GNU Image Manipulation Program 589 / 653 15.13.15.3 Options Figure 15.282: ‘Gfig’ filter options The tool bar At the top of dialog, you can find a set of icons which represents the functions of this filter. Help pop-ups are explicit. Functions for object drawing On the left part of tool bar, you can find some functions for object drawing. You enable them by clicking on the corresponding icon.
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GNU Image Manipulation Program 590 / 653 Functions for object management In the middle of tool bar, you can find tools to manage objects: • Move (Object): With this tool, you can move the active object. To enable an object, click on a control point created at the same time as the object. • Move (Point): With this tool, you can click-and-drag one of the control points created at the same time as object. Each of these points moves the object in a different way.
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GNU Image Manipulation Program 591 / 653 15.13.16.2 Activating Sphere Designer You can find this filter through Filters → Render → Sphere Designer. 15.13.16.3 Options Figure 15.284: ‘Sphere Designer’ filter parameters Preview All your setting changes will appear in the Preview without affecting the image until you click on OK. Note that the preview displays the whole image, even if the final result will concern a selection. Click the button Update Preview to see the result of the current settings.
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GNU Image Manipulation Program 592 / 653 Colors Sets the two colors to be used for a texture. By pressing the color button a color selection dialog appears. Scale Determines the size of separate elements composing the texture. For example, for the ‘Checker’ texture this parameter determines the size of black and white squares. Value range is from 0 to 10. Turbulence Determines the degree of texture distortion before applying the texture to the sphere. Value range is from 0 to 10. With values of up to 1.
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GNU Image Manipulation Program 593 / 653 15.14.2.3 Options Figure 15.285: Source 1, Source 2 Defines the source images to use for the blending. Depth Map Define the picture to use as transformation maps for the sources. Overlap Creates soft transitions between images. Offset This option shifts the merging limit, giving more or less importance to an image against the other. Scale 1, Scale 2 Same as above for Offset, but more sensitive and applied to each map separatly.
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GNU Image Manipulation Program 594 / 653 Figure 15.287: Results (a) No offset and no overlap. The limit between both images is sharp and is situated in the middle of the mask gradient. 15.14.3 Film 15.14.3.1 Overview (b) Offset = 0.980 : the (c) Overlap: the limit is (d) Scale 1 reduced to limit, sharp, is shifted so blurred. 0.056 : as with Offset, the that the image2 area is inlimit is shifted. Image-1 creased. area is increased. Figure 15.
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GNU Image Manipulation Program 595 / 653 Selection Options Figure 15.289: ‘Film’ filter options (Selection) Fit Height to images Applies the height of original pictures to the resulting one. Height This option lets you define the height of the resulting picture. If originals have different sizes, they will be scaled to this size. Color By clicking on the color dwell you can define the color of the film (around and between pictures).
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GNU Image Manipulation Program 596 / 653 Figure 15.290: ‘Film’ filter options (Advanced) Image Height Defines the height of each pictures in the resulting image. Image Spacing Defines the space between the pictures as they will be inserted in the future image. Hole Offset Defines the hole position from image border. Hole Width Defines the width of the holes in the resulting image. Hole Height Defines the height of the holes in the resulting image.
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GNU Image Manipulation Program 597 / 653 15.15.1 Optimize 15.15.1.1 Overview Figure 15.291: Example for the Optimize animation filters In this animation, the red ball goes downwards and past vertical bars. File size is 600 Kb. Optimize (Difference) : File size moved to 153 Kb. Layers held only the part the background which will be used to remove the trace of the red ball. The common part of layers is transparent.
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GNU Image Manipulation Program 598 / 653 15.15.2.2 Activate the filter You can find this filter through Filters → Animation → Playback 15.15.2.3 Options Figure 15.292: ‘Playback’ filter options This dialog has : Preview This preview of the animation automatically fits the frame size. The number of the displayed frame is shown below the preview. Buttons Three buttons are available: Play/Stop Play/Stop to play or stop the animation. Rewind Rewind to re-launch the animation from start.
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GNU Image Manipulation Program 599 / 653 15.16.1.2 Activate the filter From an image window, you can find this filter through Filters → Web → ImageMap So you get this window: Figure 15.293: Plug-in opened window Opening example with Wilber’s image The window is a small one, but you can magnify it.
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GNU Image Manipulation Program 600 / 653 Caution Contrary to other filters, this plug-in doesn’t make an image but a text file. So you must save your work in a text format. Tip In the plug-in you can open the saved text file. The areas defined in your file will be loaded and overdisplayed; if the displayed image is not the original one or not with the same size, GIMP will ask you for adapting the scale.
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GNU Image Manipulation Program 601 / 653 Chapter 16 Keys and Mouse Reference 16.1 Help Name Help – Key reference for Help menu Help F1 Help Shift+ F1 Context Help 16.
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GNU Image Manipulation Program 602 / 653 M Move Shift+ C Crop and Resize Shift+ R Rotate Shift+ T Scale Shift+ S Shear Shift+ P Perspective Shift+ F Flip T Text Shift+ B Bucket Fill L Blend N Pencil P Paintbrush Shift+ E Eraser A Airbrush K Ink C Clone V Convolve S Smudge Shift+ D Dodge/Burn Note Double click on the tool buttons opens the Tool Options dialog. C ONTEXT X Swap Colors D Default Colors Note Click on the colors to change the colors. 16.
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GNU Image Manipulation Program 603 / 653 File Ctrl+ N New image Ctrl+ O Open image Ctrl+ Alt+ O Open image as new layer Ctrl+ D Duplicate image Ctrl+ 1 Open recent image 01 Ctrl+ 2 Open recent image 02 Ctrl+ 3 Open recent image 03 Ctrl+ 4 Open recent image 04 Ctrl+ 5 Open recent image 05 Ctrl+ 6 Open recent image 06 Ctrl+ 7 Open recent image 07 Ctrl+ 8 Open recent image 08 Ctrl+ 9 Open recent image 09 Ctrl+ 0 Open recent image 10 Ctrl+ S Save image Shift+ Ctrl+ S Save under a new name Ctrl+ Q Quit 16.
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GNU Image Manipulation Program 604 / 653 Note These open a new dialog window if it wasn’t open yet, otherwise the corresponding dialog gets focus. W ITHIN A D IALOG Alt+ F4, Ctrl+ W Close the window Tab Jump to next widget Shift+ Tab Jump to previous widget Enter Set the new value Space, Enter Activate current button or list Ctrl+ Alt+ PgUp, Ctrl+ PgDn In a multi-tab dialog, switch tabs Note This accepts the new value you typed in a text field and returns focus to canvas.
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GNU Image Manipulation Program 605 / 653 Note Menus can also be activated by Alt with the letter underscored in the menu name. Z OOM + Zoom in - Zoom out 1 Zoom 1:1 Ctrl+ E Shrink wrap Shift+ Ctrl+ E Fit image in window Shift+ mouse wheel Zoom Note This fits the windows to the image size. S CROLLING ( PANNING ) Ctrl+ arrows Scroll canvas middle button drag Scroll canvas mouse wheel Scroll canvas vertically Ctrl+ mouse wheel Scroll canvas horizontally Note Scrolling by keys is accelerated, i.e.
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GNU Image Manipulation Program 606 / 653 16.6 Edit Name Edit – Key reference for Edit menu Edit U NDO / REDO Ctrl+ Z Undo Ctrl+ Y Redo C LIPBOARD Ctrl+ C Copy selection Ctrl+ X Cut selection Ctrl+ V Paste clipboard Ctrl+ K Clears selection Shift+ Ctrl+ C Named copy selection Shift+ Ctrl+ X Named cut selection Shift+ Ctrl+ V Named paste clipboard Note This places a copy of the selection to the GIMP clipboard. F ILL Ctrl+ D Fill with FG Color Ctrl+ D Fill with BG Color Ctrl+ D Fill with Pattern 16.
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GNU Image Manipulation Program 607 / 653 Layers PgUp, Ctrl+ Tab Select the layer above PgDn, Shift+ Ctrl+ Tab Select the layer below Home Select the first layer End Select the last layer Ctrl+ M Merge visible layers Ctrl+ H Anchar layer 16.8 Selections Name Selections – Key reference for Selections menu Selections Ctrl+ T Toggle selections Ctrl+ A Select all Shift+ Ctrl+ A Select none Ctrl+ I Invert selection Shift+ Ctrl+ L Float selection Shift+ V Path to selection 16.
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GNU Image Manipulation Program 608 / 653 Zoom tool click Zoom in Shift+ click Zoom out mouse drag Zoom into the area
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GNU Image Manipulation Program 609 / 653 Chapter 17 Glossary A B C D F G H I J L M P Q R S T U X Y A Alpha An Alpha value indicates the transparency of a pixel. The smaller the alpha value of a pixel, the more visible the colors below it. A pixel with an alpha value of 0 is completely transparent. Within GIMP, Alpha values can be associated with the image as a whole (the Alpha Channel) and with individual layers (a Layer Mask).
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GNU Image Manipulation Program 610 / 653 Bezier curve A spline is a curve which is defined mathematically and has a set of control points. A Bezier spline is a cubic spline which has four control points, where the first and last control points (knots or anchors) are the endpoints of the curve and the inner two control points (handles) determine the direction of the curve at the endpoints. In the non-mathematical sense, a spline is a flexible strip of wood or metal used for drawing curves.
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GNU Image Manipulation Program 611 / 653 C Channels A Channel is a single component of a pixel’s color. For a colored pixel in GIMP, these components are usually Red, Green, Blue and sometimes transparency (Alpha). For a Grayscale image, they are Gray and Alpha and for an Indexed color image, they are Indexed and Alpha. The entire rectangular array of any one of the color components for all of the pixels in an image is also referred to as a Channel.
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GNU Image Manipulation Program 612 / 653 • YUV • YCbCr CMY, CMYK CMYK is a color model which has components for Cyan, Magenta, Yellow and Black. It is a subtractive color model, and that fact is important when an image is printed. It is complementary to the RGB color model. The values of the individual colors vary between 0% and 100%, where 0% corresponds to an unprinted color, and 100% corresponds to a completely printed area of color. Colors are formed by mixing the three basic colors.
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GNU Image Manipulation Program 613 / 653 F File Format A file format or file type is the form in which computer data is stored. Since a file is stored by an operating system as a linear series of bytes, which cannot describe many kinds of real data in an obvious way, conventions have been developed for interpreting the information as representations of complex data. All of the conventions for a particular ‘kind’ of file constitute a file format.
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GNU Image Manipulation Program 614 / 653 specific fractions of these differences are dispersed among several adjacent pixels which haven’t yet been visited (below and to the right of the original pixel). Because of the order of processing, the procedure can be done in a single pass over the image. When you convert an image to Indexed mode, you can choose between two variants of Floyd-Steinberg dithering.
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GNU Image Manipulation Program 615 / 653 The name came about from the naming conventions which were in practice at MIT, where Stallman worked at the time. For programs which were similar to other programs, recursive acronyms were chosen as names. Since the new system was to be based on the widespread operating system, Unix, Stallman looked for that kind of name and came up with GNU, which stands for ‘GNU is not Unix’. In order to avoid confusion, the name should be pronounced with the ‘G’, not like ‘new’.
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GNU Image Manipulation Program 616 / 653 HSV HSV is a color model which has components for Hue (the color, such as blue or red), Saturation (how strong the color is) and Value (the brightness). The RGB mode is very well suited to computer screens, but it doesn’t let us describe what we see in everyday life; a light green, a pale pink, a dazzling red, etc. The HSV model takes these characteristics into account. HSV and RGB are not completely independent of each other.
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GNU Image Manipulation Program 617 / 653 Interpolation Interpolation means calculating intermediate values. When you enlarge (‘digitally zoom’) or otherwise transform (rotate, shear or give perspective to) a digital image, interpolation procedures are used to compute the colors of the pixels in the transformed image. GIMP offers three interpolation methods, which differ in quality and speed. In general, the better the quality, the more time the interpolation takes.
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GNU Image Manipulation Program 618 / 653 Representation of an image with layers: The final image: M Marching Ants Marching ants is a term which describes the dotted line which surrounds a selection. The line is animated, so it looks as if little ants are running around behind each other. You can disable the marching ants by unchecking the View → Show Selection option or by using the keyboard shortcut Ctrl-T.
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GNU Image Manipulation Program 619 / 653 P Parasite A Parasite is additional data which may be written to an XCF file. A parasite is identified by a name, and can be thought of as an extension to the other information in an XCF file. Parasites of an image component may be read by GIMP plug-ins. Plug-ins may also define their own parasite names, which are ignored by other plug-ins.
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GNU Image Manipulation Program 620 / 653 Now you should be able to read PostScript files with GIMP. Please note that you must not move the Ghostscript directories once the installation is complete. The installation creates registry entries which allow Ghostscript to find its libraries. (These instructions courtesy of http://www.kirchgessner.net.) PNG PNG is the acronym of ‘Portable Network Graphic’ (pronounce ‘ping’.
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GNU Image Manipulation Program 621 / 653 RGB is a color model which has components for Red, Green and Blue. These colors are emitted by screen elements and not reflected as they are with paint. The resulting color is a combination of the three primary RGB colors, with different degrees of lightness. If you look closely at your television screen, whose pitch is less than that of a computer screen, you can see the red, green and blue elements lit with different intensities. The RGB color model is additive.
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GNU Image Manipulation Program 622 / 653 Sample Merge Sample Merged is an option you can set when you use the Bucket Fill tool, the Color Picker tool and various selection tools. It is useful when you are working on an image with several layers and the active layer is either semi-transparent or has a Layer Mode which is not set to Normal. When you check the Sample Merged option, the color which is used for the operation is the composite color of all the visible layers.
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GNU Image Manipulation Program 623 / 653 U URI A Uniform Resource Identifier (URI) is a string of characters that serves to identify an abstract or a physical resource. URIs are used for the identification of resources in the Internet (such as web pages, miscellaneous files, calling up web services, and for receivers of e-mail) and they are especially used in the Worldwide Web. URL URLs (Uniform Resource Locators) are one type of Uniform Resource Identifiers (URIs).
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GNU Image Manipulation Program 624 / 653 There are color models which do not express a color by the additive basic colors, red, green and blue (RGB), but by other properties, for example, the brightness-color model. Here, the criteria are the basic brightness of the colors (from black, through gray, to white), the colors with the largest portion (red, orange, yellow, green, blue, violet, or other pure colors that lie between them) and the saturation of the colors (‘gaudy’ to pale).
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GNU Image Manipulation Program 625 / 653 Chapter 18 Bibliography 18.1 Books [APRESS00] Akkana Peck, Beginning GIMP: From Novice to Professional, Copyright © 2006 Apress Inc., Apress Inc, www.apress.com, ISBN 1-59059-587-4, http://gimpbook.com/ . [Bunks00] Carey Bunks, Grokking the Gimp, Copyright © 2000 New Riders Publishing, New Riders Publishing, www.newriders.com , ISBN 0-7357-0924-6, http://gimp-savvy.com/BOOK .
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GNU Image Manipulation Program 626 / 653 [FREETYPE] Freetype 2 home page, http://www.freetype.org/freetype2/index.html . [GHOSTSCRIPT] Ghostscript project page on Sourceforge.net, http://sourceforge.net/projects/ghostscript . [GIMP] GIMP - The Gnu Image Manipulation Program, http://gimp.org . [GIMP-DEV] GIMP Development, http://developer.gimp.org . [GIMP-DEV-PLUGIN] GIMP Plugin Development, http://developer.gimp.org/plug-ins.html . [GIMP-DOCS] GIMP Documentation project page, http://docs.gimp.
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GNU Image Manipulation Program 627 / 653 [WKPD-LZW] Wikipedia - LZW, http://en.wikipedia.org/wiki/LZW . [WKPD-PACKBITS] Wikipedia - PackBits, http://en.wikipedia.org/wiki/PackBits . [WKPD-SVG] , http://en.wikipedia.org/wiki/SVG . [XNVIEW] XnView, http://perso.orange.fr/pierre.g/xnview/enhome.html .
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GNU Image Manipulation Program 628 / 653 Appendix A GIMP History A.1 The Very Beginning According to Peter Mattis and Spencer Kimball, the original creators of GIMP, in their announcement of GIMP 0.54: The GIMP arose from the ashes of a hideously crafted CS164 (compilers) class project. The setting: early morning. We were both weary from lack of sleep and the terrible strain of programming a compiler in LISP. The limits of our patience had long been exceeded, and yet still the dam held.
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GNU Image Manipulation Program 629 / 653 Version 0.99 In February 1997, 0.99 came on the scene. Together with other developers, S and P had made several changes to GIMP and added even more features. The main difference was the new API (Application Programming Interface) and the ‘PDB’, which made it possible to write scripts; Script-Fus (or macros) could now automate things that you would normally do by hand. GTK/gdk had also changed and was now called GTK+. In addition, 0.
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GNU Image Manipulation Program 630 / 653 release Shift, then press Shift again, then sweep out the selection with the mouse, then release Shift. It can now be done more easily. For transformation tools, buttons now control which object (layer, selection or path) is affected by the transformation. You can for example transform a rectangular selection to various quadrilateral shapes. Path transformation in particular is now easier than it was before.
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GNU Image Manipulation Program 631 / 653 Script-Fu, based on ‘Scheme’, has the same drawbacks as before: not intuitive, hard to use and lacking a real development environment. It does, however, have one major advantage compared to Python-fu: Script-Fu scripts are directly interpreted by GIMP and do not require any additional software installation. Python-fu requires that you install a package for the Python language.
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GNU Image Manipulation Program 632 / 653 Appendix B Reporting Bugs and Requesting Enhancements Sad to say, no version of GIMP has yet been absolutely perfect. Even sadder, it is likely that no version ever will be. In spite of all efforts to make everything work, a program as complicated as GIMP is bound to screw things up occasionally, or even crash. But the fact that bugs are unavoidable does not mean that they should be passively accepted.
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GNU Image Manipulation Program 633 / 653 them.) Particularly if you are using the development version of GIMP, make sure that you can see the bug in the latest release before filing a report. If after due consideration you still think you have a legitimate bug report or enhancement request, the next step is to go to GIMP’s bugzilla query page (http://bugzilla.gnome.org/query.cgi), and try to see whether somebody else has already reported the same thing.
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GNU Image Manipulation Program 634 / 653 Severity In most cases you should either leave this as ‘Normal’ or set it to ‘Enhancement’, if it is an enhancement request rather than a malfunction. The maintainers will adjust the severity if they think it is warranted. Priority In most cases you should leave this at ‘Normal’, and allow the maintainers to adjust it. Setting the priority to ‘Immediate’ or ‘Urgent’ usually just manages to annoy people. Version Set this to the version of GIMP that you are using.
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GNU Image Manipulation Program 635 / 653 Duplicate This means that the same bug has already been reported by somebody else. If you see this resolution, you will also see a pointer to the earlier bug report, which will often give you a lot of useful information. Notabug This means that the behavior described in the bug report is intentional.
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GNU Image Manipulation Program 636 / 653 Appendix C GNU Free Documentation License Copyright (C) 2000,2001,2002 Free Software Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 021111307 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. C.
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GNU Image Manipulation Program 637 / 653 The ‘Cover Texts’ are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at most 25 words.
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GNU Image Manipulation Program 638 / 653 copy of the Document, free of added material. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public.
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GNU Image Manipulation Program 639 / 653 If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version’s license notice. These titles must be distinct from any other section titles.
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GNU Image Manipulation Program 640 / 653 C.9 TRANSLATION Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections.
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GNU Image Manipulation Program 641 / 653 Appendix D Eeek! There is Missing Help Sorry, but a help item is missing for the function you’re looking for. You may be able to find it in the online version of the help at the GIMP docs website. Feel free to join us and fill the gap by writing documentation for the GIMP. For more information, visit our project page on the GIMP Wiki. There is also a Mailing list available. Generally, it’s a good idea to check the GIMP project page.
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GNU Image Manipulation Program 642 / 653 Appendix E Index _ 피하기, 108 A Acquire, 305 Add Alpha channel, 395 Add Layer Mask (command), 390 Add to selection, 397 Add to Selection (command), 393 Addition, 113 Adjust FG BG, 421 Airbrush, 186 Alien Map 2, 422 Align visible layers, 405 Alpha, 609 Alpha Channel, 609 Alpha Channel>, 101 Alpha to Selection, 396 Anchor Layer, 373 Animation Animated GIF options, 68 Creating an animated brush, 87 Optimize animation, 597 Playback, 597 Antialiasing
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GNU Image Manipulation Program 643 / 653 Channel mask, 241 Channel to Selection, 239 Create a New Channel mask, 239 Delete Channel mask, 239 Dialog, 238 Duplicate Channel mask, 239 Edit Channel Attributes, 239 Introduction, 611 Move Channel mask, 239 Channel Mixer, 434 Channels Menu, 240 Checkerboard, 581 Clear, 330 Clone, 190 Close, 325 CML Explorer, 570 CMYK, 439, 441, 612 Color, 117 Additive color model, 620 Adjust level colors, 218 Channel mixer, 434 Color analysis, 437 Color Balance, 211 Color display
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GNU Image Manipulation Program 644 / 653 Images, 273 Introduction, 233 Layers, 233 Palettes, 265 Paths, 243 Patterns, 258 Preferences, 278 Data folders, 298 Display, 290 Environment, 296 Folders, 297 Help System, 283 Image Windows, 286, 288 Interface, 281 New image, 279 Theme, 282 Title and Statusbar, 289 Tool Options, 284 Toolbox, 285 Window management, 294 Templates, 275 Tools, 277 Undo History, 252 Difference, 112 Difference of Gaussians, 459 Differentiel, 460 Diffraction patterns Filter), 569 Dilate, 4
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GNU Image Manipulation Program 645 / 653 Selective Gaussian, 416 Tileable Blur, 420 Colors Adjust FG-BG, 421 Alien Map, 422 Border Average, 432 Channel Mixer, 434 Color to transparency, 438 Colorcube Analysis, 437 Colorify, 437 Colormap Rotation, 425 Decompose image, 439 Exchange colors, 423 Filter Pack, 442 Gradient Map, 432 Hot, 445 Introduction, 421 Map Color Range, 429 Max RGB, 446 Recompose image from its components, 441 Retinex, 447 Sample Colorize, 430 Semi-Flatten, 448 Smooth Palette, 449 Value Inv
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GNU Image Manipulation Program 646 / 653 Jigsaw, 578 Maze, 577 Plasma, 560 Random textures, 579 Sinusoidal textures, 582 Solid Noise, 561 Sphere Designer, 590 Web Clickable image, 598 Introduction, 598 Fit Canvas to Layers, 364 Flame, 563 FlareFX, 482 Flatten, 368 Flip, 210, 361 Flip horizontally (layer), 400 Flip vertically (layer), 400 Floyd-Steinberg, 613 Fonts Add, 120 Dialog, 270 Problems, 121 Fonts and Texts Overview, 119 Foreground color, 231 Formats BMP, 610 GBR, 86 GIF, 68 GIH, 87 JPEG, 69 PDF, 61
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GNU Image Manipulation Program 647 / 653 Illusion, 541 Image, 273 Acquire an image, 305 Canvas size, 362 change Mode, 50 Close image, 325 Color modes Menu, 358 Comment, 319 Convert Convert to grayscale, 358 Convert to indexed mode, 359 Convert to RGB mode, 358 Decompose image, 361 Re-compose image, 361 Crop Autocrop, 367 Crop according to color, 367 Crop according to selection, 366 Crop tool, 201 crop, 47 Cut off image according to guides, 362 Flip, 52 Grid and guides, 129 Image size Printing size, 364 inf
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GNU Image Manipulation Program 648 / 653 Disable, 392 Edit, 391 Intersect layer mask with selection, 394 Show layer mask, 392 Subtract layer mask from selection, 393 Modes, 103 Paste, 328, 329 Preview size, 39 Size, 103 Size managing Auto-crop, 389 Crop according to selection, 404 Resize current layer and its content, 403 Resize current layer but not its content, 402 Resize current layer to image size, 403 Stack managing Align visible layers, 405 Create a new layer, 372 Delete current layer, 374 Layer dupl
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GNU Image Manipulation Program 649 / 653 Overview, 103 Show, 392 Subtract from selection, 393 Overview, 618 Quick Mask Using Quick Mask, 80 Quick mask, 241 Selection mask, 241 Max RGB, 446 Maze, 577 Measure, 227 Menu-bar Show/Mask menu bar, 355 Menus Edit, 326 Filters, 409 Help, 313 Image, 357 Image menu, 357 Introduction, 303 Layer, 372 Selection, 334 The File menu of the image window, 316 Toolbox, 304 Toolbox File menu, 304 Tools, 408 Xtns menu (Extensions), 307 Merge Down, 374 Merge Visible Layers, 367
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GNU Image Manipulation Program 650 / 653 Photocopy, 533 Photography, 122 Pick, 454 Pixel, 619 Pixelise, 419 Plasma, 560 Playback, 597 Plugins Browser, 310 Definition, 619 Install, 138 Introduction, 137 Write, 139 PNG, 70 Polar Coords, 504 Portrait/Landscape mode, 318 Posterize, 221 Preferences, 278 Image grid, 280 Input Controllers, 292 Input Devices, 291 Preferences (command), 306 Preview Filter preview, 411 Navigation preview, 35 Navigation preview size, 281 Option of Rotate tool, 199 Previews Tab previe
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GNU Image Manipulation Program 651 / 653 Create a selection from Path, 336 Cut selection content, 327 Delete selections, 334 Editor, 336 Ellipse selection, 164 Feather selection edges, 339 Fill Fill with background color, 331 Fill with foreground color, 330 Fill with pattern, 331 Floating selection, 613 Floating selection (command), 335 Free selection, 166 Fuzzy selection, 167 Grow selection, 341 Intersect Alpha channel with selection, 398 Invert selection, 335 Move selection, 78 Paste, 328, 329 Rectangle
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GNU Image Manipulation Program 652 / 653 Tile cache, 131 Tileable Blur, 420 Tip of the Day, 314 Title bar Preferences, 289 Toolbox, 158 Active image area, 232 Brush Tools, 172 Color Area, 231 File menu, 316 Help menu, 313 Indicator Area, 232 Introduction, 33 Menu, 304 Preferences, 285 Xtns menu, 307 Tools Airbrush, 186 Brightness-Contrast, 214 Bucket Fill, 174 Clone, 190 Color Balance, 211 Color Picker, 225 Colorize, 213 Convolve, 192 Crop, 201 Curves, 220 Dialog, 277 Dodge/Burn, 194 Ellipse Selection, 164
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GNU Image Manipulation Program 653 / 653 Xtns, 307 Y YCbCr, 439, 441, 623 YUV, 439, 441, 624 Z Zealous Crop, 367 Zoom, 226, 345