基于改进型Weibull密度分布的H.264视频率失真模型研究  

Research of Improved-Weibull-Density-Based Rate-Distortion Model with H. 264

作　　者：蒙海光[1] 李兴华[1] 荆涛[1] 李少华[2] 

机构地区：[1]北京交通大学电子信息工程学院多媒体实验室,北京100044 [2]北京国铁华晨通信信息技术公司,北京100071

出　　处：《信号处理》2010年第8期1187-1192,共6页Journal of Signal Processing

基　　金：国家自然科学基金资助项目(60772042;60772098)

摘　　要：通过对视频信源的统计分析,本文提出一种改进型Weibull密度分布,并据此密度分布建立一个新的率失真模型。文章通过使用Weibull概率密度函数,逼近实际DCT系数分布,并通过编码熵理论和失真分析,将模型表示成为两个关于视频编码量化步长的函数,即码率量化(R-Q)模型和失真量化(D-Q)模型,进而估计编码码率和量化失真。仿真结果表明,该密度分布比Cauchy密度分布更逼近于实际视频序列的DCT系数统计特性,并且该模型较基于Cauchy密度分布的率失真模型能够更为精确地估计实际编码码率和失真性能。By statistical analysis of a lot of video sources, we present an Improved Weibull density distribution. We develop a new rate-distortion model which is based on Improved Weibull density distribution. We use Weibull probability density function to ap- proximate actual DCT coefficients distribution. With encoding entropy theory and distortion analysis, the model is expressed as two func- tions of the video coder quantization step size, which are rate-quantization model （R-Q） and distortion-quantization model （D-Q） that are based on the density distribution, and the model which is based on Improved Weibull density distribution is to estimate encoding rate and quantization distortion. Simulation experiments results show that the density distribution is closer to the statistical distribution of the DCT coefficients than Cauchy density distribution. The model which is based on Improved Weibull density distribution provides better estimates for the actual encoding rate and quantization distortion performance than those that are based on Cauchy density distribution.

关 键 词：改进型Weibull密度分布 Cauchy密度分布 码率量化模型 失真量化模型 率失真模型 

分 类 号：TN919.81[电子电信—通信与信息系统] TP37[电子电信—信息与通信工程]