User Guide

GNU Image Manipulation Program
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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.
The Palettes dialog shows a list of all of the palettes available; the Colormap dialog shows the colormap of the currently active
image, if it is an indexed image - otherwise it shows nothing.
You can, however, create an ordinary palette from the colors in an indexed image---actually from the colors in any image. To do
this, choose Import Palette from the right-click popup menu in the Palettes dialog: this pops up a dialog that gives you several
options, including the option to import the palette from an image. (You can also import any of GIMP’s gradients as a palette.)
This possibility becomes important if you want to create a set of indexed images that all use the same set of colors.
When you convert an image into indexed mode, a major part of the process is the creation of an indexed palette for the image.
How this happens is described in detail in Section 14.9.6. Briefly, you have several methods to choose from, one of which is to
use a specified palette from the Palettes dialog.
Thus, to sum up the foregoing, ordinary palettes can be turned into indexed palettes when you convert an image into indexed
mode; indexed palettes can be turned into ordinary palettes by importing them into the Palettes dialog.
7.13 Drawing Simple Objects
In this section, you will learn how to create simple objects in GIMP. It’s pretty easy once you figure out how to do it. GIMP
provides a huge set of Tools and Shortcuts which most new users get lost in.
7.13.1 Drawing a Straight Line
Let’s begin by painting a straight line. The easiest way to create a straight line is by using your favorite painting tool, the mouse
and the keyboard.
Figure 7.23: The dialog shows a new image, filled with a white background.
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