Tracking a moving person is challenging because a person's appearance in images changes significantly due to articulation, viewpoint changes, and lighting variation across a scene. And different people appear differently due to numerous factors such as body shape, clothing, skin color, and hair. In this paper, we introduce a multi-cue tracking technique that uses prior information about the 2-D image shape of people in general along with an appearance model that is learned on-line for a specific individual. Assuming a static camera, the background is modeled and updated on-line. Rather than performing thresholding and blob detection during tracking, a foreground probability map (FPM) is computed which indicates the likelihood that a pixel is not the projection of the background. Offline, a shape model of walking people is estimated from the FPMs computed from training sequences. During tracking, this generic prior model of human shape is used for person detection and to initializ...
Jongwoo Lim, David J. Kriegman