This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
I do not have such code examples in exact form you need, but I can give you an idea: 1. check javax.imageio.* 2. find a provider for input image and use a reader on it 3. then use writer for target image