MPEG-2量化策略的改进  

Improvements on Quantization Strategy for MPEG-2

作　　者：邓航[1] 方向忠[1] 余松煜[1] 薛震民[1] 

机构地区：[1]上海交通大学,上海200030

出　　处：《通信学报》1999年第7期27-31,共5页Journal on Communications

摘　　要：本文在 Ｍ Ｐ Ｅ Ｇ－ ２ Ｔ Ｍ ５ 量化策略的基础上作了以下改进：１根据人眼视觉特性，提出一种计算宏块活动性系数的新算法，使之能更好地反映人眼对图像的敏感程度。２根据同一帧图像内不同区域的复杂度，自适应地给不同区域分配不同数量的比特数，减少由于对每个宏块平均分配比特数产生的图像质量不均匀现象。计算机模拟结果表明：采用本算法的图像编码信噪比平均提高了 ０６ｄ Ｂ以上，而且图像的主观质量也有较大的改善。In this paper,some improvements are given based on the quantization strategy for MPEG 2 TM5:1 A new algorithm for calculating macroblocks′ activity is proposed in order to reflect the sensitivity of human visual system to the content of picture more acurately 2 Different bits are assigned to different areas adaptively based on the complexity of the areas in the same picture In this way,the uneven error distribution caused by assigning equal bits to each macroblock in TM5 could be smoothed The computer simulation result has showed that the average PSNR of pictures has increased by more than 0 6 dB,and the subjective quality of pictures has improved substantially by these modified algorithms

关 键 词：MPEG-2 TM5 自适应量化 活动性 量化策略 

分 类 号：TN919.8[电子电信—通信与信息系统] TP391.41[电子电信—信息与通信工程]