ImageMagick is open source
Apache 2.0 project that allows you to programmaticaly create, edit, compose, or convert bitmap images.
It can read and write images in over 100 formats:
ImageMagick can scale, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines and shapes
ImageMagick is a command line utility which you can choose from several libraries:
I spent about an hour looking a wide variety of commercial image manipulation applications before I stumbled across ImageMagick. I've seen it before, but don't remember it being so functional.
Its great to see such innovative and powerful open-source projects in a sea of spammy and commercial software offerings.
