Analysis of space-dependent characteristics of motion-compensated frame differences based on a statistical motion distribution model

Although it has been observed that motion-compensated frame differences increase toward block boundaries and overlapped block motion compensation (OBMC) has been shown to provide reduced blocking artifacts as well as improved prediction accuracy, there is almost no satisfactory theoretical basis that clearly interprets the space-dependent characteristics of motion-compensated frame differences, nor have the theoretical aspects of OBMC been investigated thoroughly. We first interpret the space-dependent characteristics of motion-compensated frame differences based on a novel statistical motion distribution model. We then apply the statistical motion distribution model to the analysis of prediction efficiency of OBMC. Through the analysis, we prove theoretically that OBMC can reduce and equalize the motion-compensated frame differences across a block. The analytical results are justified by empirical experiments with typical image sequences.