[Doug Norman]

Just to give some comparison benchmarks, I did some testing In LabVIEW. With compression set to 5, here are the loop rates I got:
640x480 image: loop rate = 8 per second avg
320x240 image: loop rate = 10 per second avg
160x120 image: loop rate = 13 per second avg
This might at least give you an idea of what you should be able to shoot for. A couple of other observations. With compression set to 0, loop rates suffered (expected). Increasing the compression above 5, didn't seem to improve loop rates, but it did affect the ability to find the target.