19. An assisting system of a labeling task, comprising: extracting tracks of moving objects on a set of video sequences, the set of video sequences being taken by a fixed camera, the track being movement of a moving object across a field of view of the fixed camera; choosing a video frame belonging to the track; overlaying onto said video frame, the pixels of selected bounding boxes of a tracked object at key positions along the tracks; highlighting a bounding box of the overlaid objects; rendering each extracted track into a single composite image, the single composite image representing an entire track; accepting an operation for the composite image; labeling the entire track represented by the single composite image in response to the operation; and providing training data to a training classifier on the basis of the labeled tracks; and efficiently labeling video data for training purposes and minimizing operator intervention.
20. The system of claim 19 , comprising performing background subtraction to extract the moving objects on each video frame.