Welcome to the forum.
Attaching a USB camera is problematic:
The Panda does not have the necessary USB host connector. The chip on the Panda does support USB host, and there is an article in the Wiki on
how to do this. But, there are greater problems.
Webcam support is NOT included in the libraries for the USBizi devices. USBizi is chip family used on the Panda.
There is not enough memory to hold an entire image.
You could use a serial camera, but you would have to rapidly transfer the data to an external device.
Depending upon what type of video processing you want to do, it could be challenging on a Panda.
Bottom line? The USBizi devices are not good candidates for video input and processing.
You would want a device with more memory (MBs) and Premium library support. The Premium library includes the WebCam class.
The WebCam class supporst cameras that are UVC compatible. You would have to check if your camera supported this protocol.