GraphicsMagick provides a set of commandline tools and programming APIs for manipulating, editing, and converting raster and vector images. It is derived from ImageMagick, with the objective of providing better stability and performance than ImageMagick while retaining the original MIT/X11 license.
Advanced image processing toolbox for Scilab on Unix/Linux/Mac OS
SIP is the image processing and computer vision package for SciLab, a free Matlab-like programming environment. SIP reads/writes images in formats like JPEG, PNG, and BMP. It does filtering, segmentation, edge detection, morphology, and shape analysis. Download from Git http://siptoolbox.sourceforge.net/devel
Gimp User Filter is a plugin for The Gimp (http://www.gimp.org/), originally written by Jens Restemeier back in 1997. This project is about maintaining the plugin, keeping it compatible with current versions of Gimp, and eventually extending its features