H.264/AVC中运动估计算法及改进方案

H.264/AVC Motion Estimation Algorithm and Its Improvement

H.264是新一代视频压缩编码标准,它相对于以前的视频编码标准在编码效率上有了巨大的提高,但其运动估计部分运算量大、耗时多,极大的影响了编码速度。为了减少运动估计的时间,对全零块判决进行了深入的研究,给出了自适应的全零块判决阈值,以此为基础提出了EPZS(Enhanced Predictive Zonal Search)算法的改进方案。通过与传统的运动估计算法的实验比较,可以看出改进的EPZS算法在减少了变换编码和量化的时间,提高了编码效率的情况下,保持比特率和图像质量基本不变。

H.264,the latest video coding standard,achieves significant improvement in coding efficiency compared with previous standards,but the computation mainly concentrates on motion searching and transformation,and the encoding speed is greatly decreased.In order to reduce the computation of motion estimation in H.264 encode,all-zero block decision is profoundly studied in this paper,and the adaptive threshod of all-zero block decision is given and an improved EPZS algorithm is proposed.The simulation result shows that the proposed algorithm can highly improve the speed of encoder while basically maintaining the quality of image.In short,compared with other algorithms this method will reduce the computing complexity of encoder and improve the encoding efficiency of H.264/AVC software encoder while remaining bitraste and video quality almost unchanged.