Motion-compensated video coding using sliced blocks

In international standards for video coding such as MPEG-4 and H.264, motion compensation is performed by partitioning macroblocks (square pixel sets) into multiple areas. In this paper, we propose motion compensation using sliced blocks as a new method for macroblock-based motion compensation. The partition shape is not restricted to squares or other patterns; instead, macroblocks are sliced by arbitrary line segments. This produces better agreement in shape between partitions and moving objects, as well as better motion compensation performance. In addition, when partition data are described in bitstream, adaptive prediction of segments based on partition shape of neighbor macroblocks is applied, aiming at reduction of the overhead caused by partition data. In the proposed method, coding is performed at the macroblock level, and therefore, coding mode selection and other related algorithms of conventional rate distortion optimization can be used unaltered. The proposed method was applied to forward-prediction picture coding (basic algorithm of H.264), and an improvement of coding efficiency by about 5p was confirmed. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(7): 12– 22, 2007; Published online in Wiley InterScience (). DOI 10.1002sscj.20714