基于一维数据块的AVS视频帧内编码算法.pdf

2242013.49(15)Computer Engineering and4pp/ ications计算机工程与应用基于一维数据块的AVS视频帧内编码算法王啟军WANG Qijun中国电子科技集团公司第一三十八研究所,合肥23003238th Institute, China Electronic Technology Group Corporation, Hefei 230032, ChinaWANG Qjun. Intra coding With one-dimensional data block for AVS video. Computer Engineering and Applications,2013,49(15):224-228.Abstract: T he fixed 3-tap filter in AVS intra prediction cannot adjust to various extures ell, resulting in low coding efficiencyof intra coding. Considering that texture consistency of adjacent samples is much stronger, adaptive filtering prediction based onone-dimensional block is proposed. In the novel algorithm, the sample row or column is taken as the coding unit instead of 8x8sample block, and adaptive 3-tap filter is applied to covering various texture orientations, solving the problem of weak correlation which is caused by the long distance between predicted and predicting samples. To avoid the transmitting cost of adaptivefilter coefficients. the adjacent coded one-dimensional sample block is taken as the target block and its adjacent block as thesource to generate prediction, and via least square method, it s easy to obtain adaptive filter coefficients which are directly facili-tated to the coding of current one-dimensional sample block. Experimental results show that the novel intra codingperforms conventional intra coding in AVS video by an average of 0.324 db with maximum of 0.879 db. The adaptive intra fil-tering coding based on one-dimensional block can get a stable gain of average 0.120 db compared with intra coding based ontemplate matching prediction. The novel intra coding method demonstrates a good potential in future AVS 2.0 standardKey words intra coding: texture consistency; template matching: Audio Video coding Standard(AVS)video摘要:针对AVS( Audio Video Coding Standard,音视频编码标准)视频部分内预测中固定三抽头滤波器难以适应纹理类型变化、预测精度低的问题,基于相邻一维数据块(像素行或者像素列)之间纹理一致性更强的特点,提出了基于一维数据块的帧内自适应滤波编码算法,将固定三抽头滤波器扩展为自适应滤波器,以一数据块为单位生成预测,解决参考像素与预測像素之间距离较远所带来的相关性差、预测不准确的问题。利用最小二乘方法,对已编码的相邻一维数据块进行自适应滤波预测,计算得到最优的三抽头滤波器,将其直接作为当前一维数据块的自适应滤波器,从而違免了自适应滤波器系数的传输开销。实验结果表明:新的帧内编码方法能够提高现有AVS视频帧内编码效率平均达到0.324dB,最高达到0.879dB,而且编码性能高于帧内模板匹配方法平均0.120dB.。所提出的方法在新一代的视频编码标准AVS2.0的制定中具有广阔的应用前景。关键词:帧内编码;纹理一致性;模板匹配;音视频编码标准(AVS)视频文献标志码:A中图分类号:TP37doi:10.3778/iss.1002-8331.1304-0140主流的视频编码标准广泛釆用。在AVS视频中,帧内预AVS标准是我国具有自主知识产权的新一代视频编解测用以消除当前编码块与相邻边界像素之间的相关性,如码标淮,相比于MPEG-2标准,编码效率提高了23倍,图1所示,帧内预测的基本单位是8x8的图像块,帧内预测与H.264/AVC编码效率相当,已成为国际上主流的第二代采用了五种不同的帧内预测模式,这5种模式包括4个不视频編码标准,在IPTV、数字电视、移动多媒体等方面得到同方向的帧内预测模式和1个DC预测模式,对于方向预测广泛应用。变换和帧内预测是两类主要用于消除视频图模式,除了水平和垂直模式之外,在生成最终预测时,会对像内部空域信息元余的技术手段,与变换编码相比,帧内预测像素进行(0.250.50.25)固定抽头低通滤波,提高预测结构简单,并且能够保证信息完全无损复原,被当前对纹理内容的适应性,帧内编码对AVS视频的编码效率具基金项目:国家自然科学基金(No.61003184):中国电子科技集团公司技术创新基金项日(No.J120202)。作者简介:王军(1983-),男,工程师,研究方向为视频编与通信。E-mai:wanguun308163.com收稿日期:2013-04-11修回日則:2013-06-05文章编号:1002-8331(2013)15-0224-05