Research on Zero-Block Detection Threshold in H.264/AVC

The motion search algorithm based on zero-block detection was successfully used in H.263, H.26L etc to accelerate the speed of video coding. H.264/AVC is also a video coding scheme based on motion estimation and prediction, so the motion search method based on zero-block detection will also be effective to speed up its video coding. The key of such method is to select an appropriate threshold for the zero-block detection so as to improve the speed of video coding with neither causing too much decreasing of picture quality nor causing too much increasing of bit-rate in the mean time. Considering the threshold for the zero-block detection in H.264/AVC having been proposed was not yet the best one, the authors analyzed the upper limit of threshold theoretically and gave the range of threshold for the zero-block detection in H.264/AVC, and then some experiments about the threshold are performed according to the theoretical analysis. By analyzing the experiment results, a practical threshold which can be used for the zero-block detection in H.264/AVC is proposed at the end of this paper.