Three-Zone Segmentation-Based Motion Compensation for Video Compression

Zhao Wang, Shiqi Wang, Xinfeng Zhang, Shanshe Wang, Siwei Ma

Abstract: Motion compensation has been widely employed for removing temporal redundancies in typical hybrid video coding framework. The popular video compression standards, such as H.264/AVC and HEVC, adopt the block-based partitioning model to describe the motion field due to its high-compression efficiency and relatively low-computational complexity. However, block-based motion compensation may not align with the actual object motion boundaries, potentially limiting the compression efficiency. In view of this, we propose a three-zone segmentation-based motion compensation scheme to improve the description accuracy of motion field as well as the coding efficiency. In particular, the segmentation information is implied in the reference frame instead of being explicitly signalled. Based on the segmentation information, three motion compensation zones can be identified, including one edge, one foreground, and one background zone. The foreground zone is motion compensated by the signalled motion vector of the block, and the background zone is motion compensated by the motion information implicitly derived from the local motion field. Regarding the edge zone, it is viewed as an overlapped area and the weighted compensation strategy is adopted. The proposed algorithm is implemented into the reference software VTM-1.0 of versatile video coding (VVC), and the simulation results show that the algorithm can achieve 1.14% and 1.06% bitrate savings for random access and low-delay configurations, respectively.