Segmentation-based partitioning for motion compensated prediction in video coding

In video coding standards such as Advanced Video Coding (AVC) and its successor High Efficiency Video Coding (HEVC), motion compensation is performed by partitioning each inter-predicted picture into square or rectangular regions. While HEVC introduces an efficient quad-tree based splitting of square-shaped coding blocks into prediction blocks by symmetric and asymmetric motion partitioning, the boundaries of natural moving objects can only be approximated by a fine block partitioning, resulting in a redundant representation of the motion and therefore a potential coding overhead. This paper studies the method of using a segmentation based partitioning of coding blocks into arbitrary shaped segments, where the segmentation is performed on coded reference pictures. Experimental results show that for cases where a reasonable segmentation can be obtained, bitrate reductions of around 2% can be achieved.