Didn't you think in applying for research in places like http://www.merl.com/, http://groups.csail.mit.edu/vision/, or in companies such as http://www.gesturetekhealth.com/, http://www.tandentvision.com/, etc? There is lot of interesting research in computer vision in usa, both in large and in small companies and companies and laboratories if you are interested in that. Maybe some of these companies are small enough to categorize as "startups", I don't know. You could check the always growing robotic field too.

This site could be useful for you, too: http://www.cs.ubc.ca/spider/lowe/vision.html