Fast Quarter-Pixel Motion Estimation Algorithm For H.264/AVC

H.264/AVC is the newest international video coding standard. For the enhancement of the coding efficiencies, the new standard adopts new tools also followed: multiple reference picture, variable block-size with seven block sizes in motion prediction, quarter-pixel accuracy for motion vector, short word-length integer transform, context-adaptive entropy coding and loop filter deblocking. However, the high performance comes at significantly increasing the computation complexity. Experiments demonstrate that motion estimation can consume 60% to 80% of the total encoding time of the H.264 codec.At first,in this paper the Principle of video coding and basic concepts are introduced briefly , then we summarized the video Coding Standards which are used widely. This paper is based on these content. In the third chapter, we mainly discussed the motion estimation technique. And studying several important search arithmetic in detail. In the fourth chapter, a fast quarter-pixel motion estimation algorithm was proposed in this paper. The proposed algorithm based on mathematical models of the motion compensated prediction errors. Unlike conventional quarter-pixel accuracy hierarchical motion estimation algorithm, proposed algorithm can avoid fractional-pixel interpolation and subsequent fractional-pixel search after integer-pixel accuracy motion estimation. Then a research about the case of optimal integer-pixel on the edge of image was taken. Experiments show that the proposed algorithm greatly reduces the computational complexity of quarter-pixel motion estimation, while keeping the nearly equal quality of the image.At the end of paper, there are a conclusion and pointing out the promising direction of future research.