Motion is an important cue for the human visual system Mobiles have fascinated children, Zeno (circa 500 B.C.) studied moving arrows to pose a paradox and Zeke is investigating the human brain devoted to the understanding of motion. In computer vision research, motion has played an important role for the past thirty years. An important application of motion research has emerged in the past decade. This area is devoted to the study of people – facial expression recognition, gesture recognition, whole-body tracking and human activity recognition. The broad area is at times called “looking at people.” In addition, study of human motion is of interest to number of disciplines including psychology, kinesiology, choreography, computer graphics and human-computer interaction.