摘 要：為提高視頻壓縮效率，在傳統搜索算法的基礎上，結合實際運動圖像中的運動向量，以水平方向向量為主要特點，提出一種利用偏水平十字模板搜索與偏向雙菱形模板搜索相結合的改進搜索算法。該改進算法可以根據運動向量的特點來減少模板的搜索點數，達到提高視頻壓縮效率、節省運動估計時間的目的。性能對比實驗結果表明：該改進算法適合各種運動類型的視頻序列，尤其適用于運動變化劇烈的序列，并且能夠在PSNR值和碼率值極其接近FS算法的情況下，對QCIF格式圖像的運動估計時間（MET）減少約95%，對CIF格式圖像的運動估計時間（MET）減小約94.5%，大大減少運動估計時間。
關鍵詞：視頻壓縮；H.264標準；運動估計；快速搜索算法
文獻標志碼：A 文章編號：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
