视频编码中算术编码的二进制化研究

二进制化是自适应二进制算术编码中的重要步骤,在二进制级别进行概率估计与编码,能有效降低编解码计算复杂度。本文提出一种新型二进制化方法,根据相邻变换块的非零系数个数存在的高度相关性,对变换块的非零系数个数进行自适应二进制化;在设计二进制化算法的过程中,还针对概率分布近似对称的情况,提出一种简化的将语法元素映射为码字序号的规则。实验结果表明,与传统方法相比,新的算法能在压缩效率相当的前提下,有效降低计算复杂度。

A Novel Binarization Scheme in Arithmetic Coding

Binarization is an elementary step in the framework of contextbased adaptive binary arithmetic coding.It is introduced to simplify the context modeling and the subsequent arithmetic coding process.In this paper,we propose a novel binarization scheme for arithmetic coding.Based on the observation that the numbers of nonzero coefficients in neighboring blocks are highly correlated,the number of nonzero coefficients of a block is specifically binarized according to the numbers of nonzero coefficients of its top and left neighbors.In addition,a novel mapping rule is designed to map a syntax element to a code number,according to the observed features of probability distribution.Experimental results show that compared to the conventional scheme,this scheme can reduce decoding complexity with comparable coding efficiency.