Contour coding technique employing motion information

In this paper, a new contour coding technique using motion information is proposed, for the object-oriented video coding. In the conventional technique using motion information by Gu, the region-based motion compensation is performed, and only the contours neighboring the motion- failure (MF) regions are encoded by the proper intra-frame contour coding technique. However, since even small local motions within a region may incur the MF regions, the temporal correlation of the contours cannot be effectively exploited by the conventional techniques. In our approach, those MF regions are significantly reduced by employing the two-stage motion compensation. While the region-based motion compensation is performed in the first stage, the MF regions proceed to the second stage motion compensation to find the contours in the previous frame which coincide with the contours of the MF regions. In addition, by introducing the notion of the error band, the current contours can be properly fitted to the motion compensated contours using inter-frame relationship of the contours. From the simulation results, it is shown that the proposed technique provides better performance than the conventional technique by Gu. Moreover, by varying the width N of the error band, it is shown that the bit amount for the shape information can be adjusted according to the channel condition.