User Guide

GNU Image Manipulation Program
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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.
EXAMPLES
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.
Let us start with a 1D brush which will allow us to study selection modes action. We can imagine it like this:
Follow these steps:
1. Open a new 30x30 pixels image, RGB with Transparent fill type. Using the Text tool create 4 layers "1", "2", "3",
"4". Delete the "background" layer.
2. Save this image first with .xcf extension to keep its properties then save it as .gih.
3. The Save As Dialog is opened: select a destination for your image. OK. The GIH dialog is opened: Choose Spacing
100, give a name in Description box, 30x30 for Cell Size, 1 dimension, 1 rank and choose "Incremental" in Selection
box. OK.
4. You may have difficulties to save directly in the GIMP Brush directory. In that case, save the .gih file manually into
the /usr/share/gimp/gimp 2.0/brushes directory. Then come back into the Toolbox, clic on the brush icon to open the
Brush Dialog then click on "Refresh". Your new brush appears in the Brush window. Select it. Select pencil tool for
instance and click and hold with it on a new image
You see 1, 2, 3, 4 digits following one another in order.
5. Take your .xcf image file back and save it as .gih setting Selection to "Random": digits will be displayed at random
order:
6. Now select "Angular" Selection:
A 3 dimensions image hose We are now going to create a 3D animated brush: its orientation will vary according to brush
direction, it will alternate Left/Right hands regularly and its color will vary at random between black and blue.
The first question we have to answer to is the number of images that is necessary. We reserve the first dimension (x) to the
brush direction (4 directions). The second dimension (y) is for Left/Right alternation and the third dimension (z) for color
variation. Such a brush is represented in a 3D array "myarray(4,2,2)":
There are 4 ranks in first dimension (x), 2 ranks in second dimension (y) and 2 ranks in third dimension (z). We see that
there are 4x2x2 = 16 cells. We need 16 images.