I’m currently working on a university project which involves lots of image manipulation and effect stuff, and until a few moments ago I wasn’t able to find any good graphic effect library at all. Not even some kind of algorithm overview. But luckily I just found a Java Image Filters library written by a guy named Jerry. It includes sample implementations for lots of filters and effects, such as an Oil Filter, a Crystalize Filter and lots of other cool stuff.
If you know other open source algorithms implementations or descriptions for image filters, I’d be happy if you’ d leave a comment :)