摘要
本文在研究ＭＰＥＧ－２ＴＭ５建议的自适应量化策略的基础上，设计了一种新的自适应量化器。以块为基础分析宏块的局部视觉活动特性，并通过综合评价宏块中各块的视觉活动特性来最终决定自适应视觉量化因子。实验结果表明，本文所设计的自适应量化器能均匀分布图像编码主观失真，改善了图像质量，特别是减少了平坦区的块效应，降低了平坦区强边缘的失真。
Based upon studying the strategy for adaptive quantization suggested by MPEG-2 Test Model 5,a new quantizer is presented in this paper.Block-based visual activities are analyzed to exploit local perceptual characteristics in the macroblock.In order to decide the adaptive perceptual quantization factor,macroblock characteristic is identified by evaluating comprehensively each block's local activity within this macroblock.Experiment results show that coding distortion is uniformly distributed across the image with the proposed quantizer ,and picture quality is improved. In particular,block artifacts in flat area and distortion at edges on flat backgrounds are significantly reduced.
出处
《通信学报》
EI
CSCD
北大核心
1995年第5期102-106,共5页
Journal on Communications
基金
国家自然科学基金
