一种H.264残差系数修剪算法  

A Residual Coefficients Pruning Algorithm in H.264

作　　者：侯兴松[1] 薛端[1] 

机构地区：[1]西安交通大学电子与信息工程学院,西安710049

出　　处：《西安交通大学学报》2010年第10期52-56,共5页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(60602024);西安交通大学校内科研基金资助项目(xjj2009042)

摘　　要：针对H.264残差系数编码中位置信息占用码率较多这一问题,提出了一种H.264残差系数修剪算法.该算法首先对视频序列进行预测、变换、量化以及扫描,然后对扫描后获得的残差系数进行线性分组,并采用率失真优化准则对残差系数分组进行修减,再在给定量化步长范围内计算每一个宏块在不同量化步长下的修剪结果,最后将率失真代价最小时对应的修剪剩余残差系数编码输出.实验结果表明,与H.264残差系数编码算法相比,该算法在相同码率下的峰值信噪比最多可以提高0.9dB,在相同信噪比下最多可以节省17%的码率.该算法没有改变H.264的码流结构,与标准兼容.A pruning algorithm is proposed to reduce the encoding bits for the map information of residual coefficients in H.264.Video sequences are predicted,transformed,quantized,and scanned.Then residual coefficients obtained from scanning are divided into linear groups,and then the groups are pruned out using the rate-distortion optimization（RDO）sense.Furthermore,the pruning results of each macroblock with different quantization steplengths are calculated in a given range.Finally the remaining coefficients with the minimal rate-distortion cost are encoded and transformed.Experimental results show that the proposed algorithm has better RD performance than the residual coding method in H.264at the relatively high bitrates.The proposed algorithm gains an 0.9dB increase on the peak signal to noise ratio（PSNR）at the same bitrate,or equivalently,a 17%rate saving at the same PSNR.Moreover,the proposed algorithm does not change the bit-stream structure of H.264,and is compatible with the H.264standard.

关 键 词：系数修剪 量化 率失真优化 H.264标准 

分 类 号：TN919.8[电子电信—通信与信息系统]