There is the ezGestures gesture recognition library for Processing. If it's not of direct help, it may give some inspiration to get you started through it's open source code.

Also, please take the time to read where to place threads. Exhibition is -as the name already implies- to showcase programs and code examples, not to ask questions.

Sorry I accidently put it here. I've seen ezGestures earlier, but it's for mouse and wii remote gestures. Basicly I want to track an object's path, for example i could recognize a gesture if I would put a red tape on my finger and I would be able to track it's movement. Is this possible?