A fast block-matching motion estimation algorithm for H.264/AVC

The H.264 video coding standard has achieved a significant improvement in coding efficiency compared to previous standards, such as MPEG1/2/4 and H.261/H.263, whereas its complexity is significantly increased at the same time. In an H.264 encoder, the most time consuming component is variable block size motion estimation. In order to reduce the complexity of motion estimation, a fast block matching motion estimation algorithm is proposed in this paper, which is based on the diamond search(DS) algorithm. This algorithm well exploits the correlation between video sequence motion activity and macro-block coding pattern and motion vector statistic characteristics, judged by rate-distortion optimization rule, so it significantly reduces the search complexity of motion estimation. Experimental results show that the algorithm provides faster search speed than FS and DS algorithm while it provides the almost the same value in PSNR.