I have defended my Ph.D. thesis in the Department of Computer Science, University of Maryland at College Park in August 2005. My advisors are Prof. Larry Davis and Prof. Ramani Duraiswami. I was also affiliated with the Institute for Advanced Studies, the Computer Vision Laboratory, and the Perceptual Interfaces and Reality Laboratory. I was working at the Sarnoff Corporation, New Jersey. Now I am working at Leidos.