I need it for some realtime video processing (head/finger tracking with OpenCV, TouchLib, tBeta...), could spend up to about 150$... True 640x480 would be of course better.
I've read of some webcams (even low cost ones) that support 640x480@60fps, like Phillips SPC900-NC, Sony PlayStation3 Eye or Logitech QuickCam Pro 9000, but I'm not sure on how they're working on Linux...
It might work but many capture cards can't do much better than 320x240@30 fps and most video cameras can't do more than 30fps. The TV resolution is probably no more than 300 lines maybe a little more or little less.
The Micron MT9T031 sensor claims 93 fps (VGA) at 640x480 which is rather impressive.
I am not sure how well it actually performs but I believe elphel cameras, which use that sensor, have a pretty good reputation.
That's definitely too much...
Anyway some low-cost webcams (like the ones I listed) can reach 640x480@60fps (or 320x240@120 or 1280x960@30). Well, they probably interpolate or something, I'm not sure, but it's still a lot better than nothing.
I would like to know if I can get those performances on Linux... My (very cheap, brandless) webcams can do 10FPS at most (no matter the resolution), due to gspca modules...
You can get the elphel sensor package for $150 with the Micron MT9T031 sensor and a cheap lens for about $20, then you would have to either build your own Linux camera base ( embedded ) or interface it with a Linux PC.
Sadly, I don't know what kind of interface it uses internally.
Since elphel is open hardware and open software you can find out
The Phillips Model SPC 900NC is listed at 90 fps, 1.3 Mpxls with automatic face tracking & digital zoom and built in microphone and LED lighting. This sells for $20.00 marked down to $8.95 at Ocean State job lot (Mass. stores so far).