摘  要：为提高视频压缩效率，在传统搜索算法的基础上，结合实际运动图像中的运动向量，以水平方向向量为主要特点，提出一种利用偏水平十字模板搜索与偏向双菱形模板搜索相结合的改进搜索算法。该改进算法可以根据运动向量的特点来减少模板的搜索点数，达到提高视频压缩效率、节省运动估计时间的目的。性能对比实验结果表明：该改进算法适合各种运动类型的视频序列，尤其适用于运动变化剧烈的序列，并且能够在PSNR值和码率值极其接近FS算法的情况下，对QCIF格式图像的运动估计时间（MET）减少约95%，对CIF格式图像的运动估计时间（MET）减小约94.5%，大大减少运动估计时间。

关键词：视频压缩；H.264标准；运动估计；快速搜索算法

文献标志码：A       文章编号：1674-5124（2015）12-0128-04

Research on improved motion estimation algorithm and its performance

comparison experiment based on H.264

JIANG Lifeng

（School of Information Science and Engineering，Fujian University of Technology，Fuzhou 350108，China）

Abstract: To improve video compression efficiency， this paper， based on traditional search algorithms and the motion vector that is chiefly moving in the horizontal direction in actual motion images， has put forward an improved search algorithm， which is a combination of partial to horizontal cross template searching and biased double-diamond template searching. In accordance with the feature of the motion vector， the number of searching spots can be reduced so as to increase the video compression efficiency and shorten the motion estimation time. The performance contrast experiment shows that this improved algorithm suits all types of motional video sequences， especially those changing drastically in movement. Under the condition that the value of PSNR and code rate is very close to FS algorithm， it can decrease around 95% of the motion estimation time (MET) of QCIF pictures and about 94.5% of the MET of CIF pictures respectively compared to the FS algorithm.

Keywords: video compression； H.264 standard； motion estimation； fast search algorithm