一种利用预测运动矢量改进的H.264快速运动估计算法  

Improved Method of H.264 Fast Motion Estimation Using Predictive Motion Vector

作　　者：郭继昌[1] 邱琳耀 张雪[1] Guo Jichang Qiu Linyao Zhang Xue(School of Electronic Information Engineering, Tianjin University, Tianjin, 300072, Chin)

机构地区：[1]天津大学电子信息工程学院,天津300072

出　　处：《数据采集与处理》2017年第2期278-285,共8页Journal of Data Acquisition and Processing

基　　金：高等学校博士学科点专项科研基金(20120032110034)资助项目

摘　　要：针对H.264标准推荐使用的快速运动估计算法——非对称十字型多层次六边形格点搜索(Unsymmetrical cross multi-hexagon grid search,UMHexagonS)算法搜索速度慢的问题,提出了一种改进算法。在起始搜索点的预测环节,建立预测矢量集,并根据预测矢量集的长度信息决定后续的搜索策略;在全局搜索环节,利用预测运动矢量之间的相关性适当跳过某些搜索步骤,并更换一些搜索模板;并且,根据整数变换和量化的特性检测全零系数块,提前终止运动估计过程。实验结果表明,在量化步长为28时,本文算法比UMHexagonS算法平均减少了34.80%的运动估计时间,同时编码性能基本不变。该算法在不同量化步长的条件下能够适应不同运动强度的视频序列,是一种适合H.264的速度快且性能好的快速运动估计算法。An improved algorithm is proposed based on unsymmetrical cross multi-hexagon grid search（UMHexagonS）,which is a fast motion estimation algorithm recommended by H.264.In the prediction link for initial search points,predictive vector sets are established,and the follow-up search strategy is determined according to the length of prediction vector sets.In the global search link,the correlation between prediction motion vectors is used to skip some search steps,and some templates are replaced.In addition,the block of zero coefficients is detected to terminate the motion estimation process in advance,according to characteristics of integer transform and quantization.Experimental results show that,when the quantization step size is 28,the proposed algorithm reduces the motion estimation time by 34.80%compared with the UMHexagonS algorithm,while maintaining the performance.Finally,the algorithm can adapt to video sequences with different motion intensity under different quantization steps,which is a fast motion estimation algorithm with fast speed and good performance suiting for H.264.

关 键 词：视频编码 运动估计 预测运动矢量 H.264 非对称十字型多层次六边形格点搜索 

分 类 号：TN919.81[电子电信—通信与信息系统] TP301.6[电子电信—信息与通信工程]