Burn is a small and compact 32x32 256 color image (sprite) editor for Dos (or POSIX, using Dosbox or Dosemu). It currently contains several gfx-effects than can be applied to images, animation features and a tiny scripting language (amongst others).
SImg is astronomical image processing software for Linux. Some of the features are deconvolution (various algorithms), removing interferences, automatic shifting of images, computation of PSF and and a visualization tool.