一种类DCT的8×8整数变换  

A DCT-like 8×8 Integer Transform

作　　者：田晓华[1] 朱光喜[1] 王曜[2] 

机构地区：[1]华中科技大学电信系宽带无线通信与多媒体系统研究中心,武汉430074 [2]香港中文大学讯息工程系

出　　处：《中国图象图形学报（A辑）》2004年第8期916-921,F006,共7页Journal of Image and Graphics

基　　金：国家"8 63"资助项目 ( 2 0 0 2 AA1190 10 )

摘　　要：整数变换因其高效的计算性能而被最新的国际视频编码标准 H.2 6 4采纳 ,我国的第一个音视频编码标准AVS也将采用 8× 8整数变换。变换模块的性能直接影响编解码器的性能 ,所以选择性能优异的变换基尤为重要。本文在 8× 8类 DCT整数变换原理的基础上 ,提出了一种结合能量集中率和去相关效率的变换基变换性能评价方法 ,同时考虑计算复杂度 ,在理论上选出了几组性能较好的整数变换基。通过分析视频序列测试结果 ,讨论得出不同变换基的适用场合 。Integer transform has been adopted by the newest international video coding standard H.264 for its high efficiency of computation. Our first national audio and video coding standard AVS will also adopt 8×8 integer transform for video compression. As transform module has strong influence on the efficiency of codec, it is important to select an excellent transform basis (transform matrix). In this paper, after introduction of basic theory of DCT-like 8×8 integer transform, the authors bring out three principles of transform basis evaluation: (1) orthogonality, (2) transform efficiency, and (3) computation complexity. First, the transform bases satisfied principle (1) can be found in a predefined data range. Principle (2) is embodied in a novel method combining evaluation of transform efficiency from two aspects: energy compaction and decorrelation efficiency in a proper range of correlation coefficients of input image prediction difference data. By using such evaluation method and taking principle (3), computation complexity of fast transform algorithm into consideration, several theoretical highly efficient transform bases such as (10,9,6,2), (5,6,4,1) and (4,5,3,1) have been picked out and tested in the actual video sequences. Based on careful analysis of testing results, the authors find out the proper situation that each basis fits for and prove the validity of transform basis performance measurement that uses this theoretical evaluation method.

关 键 词：整数变换 离散余弦变换 能量集中率 去相关效率 音视频编码标准 

分 类 号：TN912.3[电子电信—通信与信息系统]