The Gimp Tutorial:
Converting a sequence of image files into an animated .GIF image file
This tutorial explains the basic steps involved in converting a series of image files such as those rendered by POV into an animated .GIF file. To do so, we recommend using The Gimp, an extremely powerfful and versatile open source tool. The Gimp is the open source's answer to top-end commercial image editing programs such as PhotoShop� and now features an extra set of tools oriented towards animation.
Step 11:
The other window looks similar to the one in step 4, but while that had 1 layer, this one has 25, as can be read in the dialog's top bar. 25 is also the number of images in the rendered sequence. Layers are the digital equivalent of the onionskins used by animators, each containing one image or frame of the animation. How to view, manipulate and work with layers is beyond the scope of this document, but key to such interesting processes as compositing.
Step 12:
Because the .GIF file format supports only a reduced number of colors, it is advisable to reduce them "by hand" before saving the animated image. To do so, go to the Image menu, select the Mode option and then the Indexed option.
Step 13:
This brings up the Indexed Color Conversion dialog, which allows us to tweak the color reduction parameters. 256 is the maximum number of colors that a .GIF file will accept. Since this is a step that reduces quality, it is advisable to use the Floyd-Steinberg (reduced color bleeing) color dithering option to get the best results.
Step 14:
Color reduction might again take a little while. Next it is advisable to take a step that will reduce the file size. Go to the Filter menu, choose Amination and then Optimize (for GIF)
Step 15:
Now it is time to save the file. Choose the Save as... option of the File menu.
