B. Candidate Owner Detection
Inside the period KeyTime, objects and their owners must stick together (as we mentioned above). Therefore, by tracking objects along time-backward direction from Tapp to Tstartapp - e (where e is a deviation for not missing a useful information to identify candidate owners. In our case, e is 100 frames), we can capture the covering area that contains owner area. For object tracking, we use MEANSHIFT [6] and Kalman filter [9]. After finishing tracking object, the candidate owner area is selected by using background sub- traction and connected component methods. Nevertheless, this task cannot guarantee that the detected area contains