using usb camera on DE2

Hi:

everybody!

I want use usb camera on DE2 board to get pic and then showed it via VGA.

I really don't know how to control the usb port,and how can the camera work?

I konw Altera has an example of using usb mouse on de2,but what can I learn from it?can somebody give me a guide about using usb camera on de2?

Thank you!Waiting for apply!