grabbed video as a source of entropy

[Eugene Leitl]

I've recently aquired a video camera (bttv-based 3Com Bigpicture, can
do 30 fps true color 640x480). I've noticed that under certain
conditions images can become quite noisy. Does anyone has data on the
amount and quality of the entropy produced?

I wouldn't mind any pointers to sources extracting, say, LSB from
grabbed frames.