Experiments on block-matching techniques for video coding

Video compression is becoming increasingly important with the advent of compression standards and broadband networks. Recently, several block-based motion-estimation algorithms to exploit the temporal redundancies in a video sequence have been reported in the literature. Some of these algorithms tend to be either computationally expensive or to converge to a local optimum. In this paper, we present results for various block-matching techniques and propose a low-complexity block-matching motion-estimation algorithm that is useful for hybrid video coding schemes, including MPEG video. This algorithm consists of a layered structure search, and, unlike other fast block-matching methods, it does not converge to a local optimum. The proposed method employs a novel matching criterion, namely, the modified pixeldifference classification (MPDC), that offers simplicity with other potential advantages.