[BugRoger]

Before I spend my day working on Java (again) may I suggest something else? Try ImageMagick. It might be just what you are looking for. If you're running Linux it's probably already installed... I'm not very experienced in using it but it is *very* powerful. I use it for on the fly generation of thumbnails on my webserver.

I browsed the Online docu and there is a blur filter and an option to select a specific set of colors. I haven't tried it but it seems like this should work.