Analysis of space-dependent characteristics of motion-compensated frame differences

To design an optimal coding algorithm, a signal-source model that accurately reflects the signal characteristics is required. Although many investigations have been made on various aspects of motion-compensated frame differences, most of them assume that motion-compensated frame differences are homogeneous. Recently, however, it was observed that the variances of motion-compensated frame differences at block boundaries tend to be larger than those at block centers. In this paper we present a theoretical interpretation of the space-dependent characteristics of motion-compensated frame differences. The analysis is based on a statistical model for motion. The analytical results are justified by empirical experiments with typical image sequences