ImageMagick 7
darktable is an open source photography workflow application
Library to encode and decode images in WebP format
A fast image processing library with low memory needs
Swiss army knife of image processing
A collection of packages providing extra functionality for GNU Octave
Resilient Image Library - successor to DevIL
ProStack - a platform for image processing and analysis
Image processing library in C/C++
Tools to access streams in PDF-files at the object level.
Easy converting PNM to (MASK+FG+BG)-pdf.
Easy converting pgm and ppm to (MASK+FG+BG)-djvu.
Libraries and command line tools for medical image processing.
Graphic Live Mixer
Digital image processing programs for Windows and Linux systems.
Some image processing tools
A small C library for building user interfaces with C, XML and CSS.
Tools to train Image Operators automatically from a set of samples.
Advanced image processing toolbox for Scilab on Unix/Linux/Mac OS