Here you go: http://www.oracle.com/technetwork/java/javasebusiness/downloads/java-archive-downloads-java-client-419417.html
Maybe this is interessting, too. I saw they provide some extensions:
http://java.net/projects/imageio
I know about Sanselan and ImageJ, too, but do not know
if and how they give you the ability to read the pixelcolor.
But as long as you can get a BufferedImage
in Java you should
be able to do what is needed.