AVS2帧内预测模式快速选择算法  

Fast intra prediction mode decision algorithm for AVS2

作　　者：郑成[1] 王国中[1] 范涛[1] 赵海武[1] 

机构地区：[1]上海大学通信与信息工程学院,上海200444

出　　处：《电视技术》2016年第10期1-5,21,共6页Video Engineering

基　　金：国家"863"计划项目(2015AA015903)

摘　　要：AVS2是我国新一代具有自主知识产权的视频编码标准,相比于同代国际标准HEVC在压缩效率上基本相当,而比上一代国标AVS在压缩效率上提升了一倍左右。然而随着压缩效率的大幅度提升,其编码复杂度也急剧增加,例如复杂的块划分,更多的预测模式等。为提升编码速度,使其适用于实时应用,提出一种快速帧内模式选择的算法,一方面通过对各帧内模式的利用率分析,避免了RMD(Rough Mode Decision)野蛮遍历各种模式;另一方面,通过先验知识构成终止RDO(Rate-Distortion Optimized)条件,且根据纹理估计进一步优化其终止条件,可有效提高RDO的效率。实验结果表明,在图像质量几乎不下降的前提下,优化后的RMD模式命中率高达98%,全Ⅰ帧编码BD-Rate大约增加0.96%,而编码时间节省了约34%,大幅提升了AVS2帧内编码的速度。AVS2 is a new generation of video coding standard with independent intellectual property rights. Compared with the in- ternational standards HEVC, it is roughly equal on compression efficiency. Compared to AVS1 ,AVS2＇s compression efficiency is improved twice. Along with the increases in compression efficiency, its complexity has increased dramatically, such as Complex block partition, more prediction mode and so on. To increase encoding speed, a fast intra mode decision algorithm is proposed in the paper. On the one hand, through the analysis of the utilization of intra mode, proposed algorithm can avoid the traverse of vari- ous modes in the RMD. On the other hand, the termination condition of RDO （Rate-Distortion Optimized） ,based on prior knowl- edge and texture estimation, has effectively improved the speed of RDO. Experimental results have show that, on the premise of al- most no decline in quality of the image, AVS2 intra-frame coding time is greatly reduced.

关 键 词：AVS2 帧内预测 模式选择 纹理方向 

分 类 号：TN919.81[电子电信—通信与信息系统]