<P>PROBLEM TO BE SOLVED: To provide a robust adaptive, appearance model for motion-based tracking of a complicated natural object. <P>SOLUTION: This appearance model 120 includes a stable model component (S) learned over a long time passage and a transitive component (W/L) learned over a comparatively short time passage (for example, 2-frame motion component (W) and/or an outlier processing component (L)). An online EM algorithum is used, and adaptation of an appearance model parameter is performed with passage of time. Mounting of the approach is developed based on filter response from a steerable pyramid. The appearance model is used in a motion-based tracking algorithum 110, and provides robustness against an outlier of an image generated by occlusion. <P>COPYRIGHT: (C)2003,JPO 
APPEARANCE MODEL FOR VISUAL MOTION ANALYSIS AND VISUAL TRACKING