利用人眼视觉特性的低比特率小波图像压缩  

Low-bit-rate wavelet-based image compression using human visual characteristics

作　　者：田杰华[1] 顾晓东[1] 汪源源[1] 

机构地区：[1]复旦大学电子工程系,上海200433

出　　处：《仪器仪表学报》2010年第11期2515-2520,共6页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金项目(60671062);国家重点基础研究发展计划项目(2005CB724303)资助

摘　　要：图像压缩的视觉有效性直接与其所保留的视觉重要信息有关。心理生理学实验结果显示,人眼对图像的边缘、平滑、纹理区域的敏感度不同,同时对小波分解后不同子带部分小波系数的敏感度也不同。本文据此提出了一种新的低比特率小波图像压缩方法。该算法对图像不同区域小波系数进行不同的量化,同时对图像小波分解不同子带系数进行视觉重要性加权,保证优先传输视觉上最重要的系数。实验表明,本文算法适合于低比特率的图像压缩,将其嵌入EZW编码算法中,与传统的EZW算法相比,重构图像的主观视觉质量评价指标VIF(visual information fidelity)值更高,具有更清晰的视觉效果。The visual efficiency of image compression depends directly on the amount of visually significant information retained. Psychophysical studies show that human visual system is sensitive differently to edge, smooth and texture regions of image, and the wavelet coefficients within different subbands. Based on these characteristics of human visual system, this paper proposes a new technique that implements wavelet-based image compression at low bit rates. By using diverse quantization step-sizes in different regions and diverse weights for different subband coefficients, wavelet coefficients are reordered and coded according to their perceptual importance. Experimental results show that when implemented into EZW, the proposed scheme performs better than conventional EZW algorithm both in VIF criteria and subjective quality of the reconstructed images, especially at low bit rates.

关 键 词：人眼视觉系统 对比敏感度函数 小波变换 图像压缩 

分 类 号：TN911.73[电子电信—通信与信息系统]