基于分段式拟合的低比特率图像压缩编码方法  

A Low-bit Rate Image Compression Algorithm Based on Piecewise Matching Pursuits

作　　者：李恒建[1] 陈怀新[2] 张家树[1] 

机构地区：[1]西南交通大学信号与信息处理四川省重点实验室,成都610031 [2]中国电子科技集团公司第10研究所,成都610036

出　　处：《电子与信息学报》2008年第9期2211-2215,共5页Journal of Electronics & Information Technology

基　　金：四川省青年基金项目(03ZQ026-033);四川省应用基础研究项目(2006J13-10);教育部新世纪优秀人才支持计划项目(NECT-05-0794);西南交通大学博士生创新基金(2007)资助课题

摘　　要：为了提高图像在低比特率条件下的解码质量和视觉效果,该文提出一种基于稀疏分解的低比特率图像压缩编码新方法。利用二维不可分离、具有各向异性尺度的墨西哥草帽小波作为生成函数,这种函数构建的冗余字典能够有效捕获图像边缘轮廓特征。为降低原子投影系数的冗余度和减小其编码量,对图像稀疏分解投影的系数采用分段式拟合。获得的图像压缩码流具有渐进特性的,满足现代无线通信对可伸缩码流的要求。实验结果表明,在低比特率下,该文方法与JPEG2000方法和通常的稀疏分解编码法相比,有更高的峰值信噪比;解压图像无振铃效应,主观效果好。A novel image coding scheme based on sparse decomposition is proposed to improve decoded image quality and vision impact at low bit-rates. The over-complete dictionary, which is built on anisotropic refinement and rotation of 2D nonseparable Mexican hat wavelet, can efficiently capture edge characteristics present in natural images. And to improve the coding efficiency, an atom modulus which is piecewise approximated by the least squares line is proposed. Simultaneity, the stream can simply be truncated at any point to provide a SNR-adaptive bit-stream, which is very suitable for transmission in wireless communication. Experimental results show that the objective and subjective quality of decoded image is, at low bit rates, comparable to the -state- of- the art image coder, represented here by JPEG2000 and other based on Matching Pursuit methods. Also, the coding artifacts in the MP algorithm are less annoying than the ringing introduced by wavelets.

关 键 词：图像压缩 稀疏分解 分段式匹配追踪 各向异性原子 

分 类 号：TN919.8[电子电信—通信与信息系统]