基于稀疏重建的压缩图像质量提高方法  

Compression image quality improvement via sparse reconstruction

作　　者：宋蓓蓓[1] 孙文方[2] 

机构地区：[1]长安大学信息工程学院,陕西西安710064 [2]中国空间技术研究院西安分院,陕西西安710000

出　　处：《华中科技大学学报（自然科学版）》2012年第9期30-33,43,共5页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(60902075);中央高校基本科研业务费专项基金资助项目(CHD2012JC067)

摘　　要：为了克服JPEG2000中低码率压缩图像在边缘处表现出的明显振铃效应严重降低了图像的人眼视觉质量的问题,在迭代凸集投影理论基础上,分析了迭代去噪方法恢复图像变换域稀疏数据的机理,提出了JPEG2000压缩图像重建算法.该算法保持压缩图像在小波域中的非零系数不变,通过迭代去噪恢复其他位置的小波系数.结果表明:提出方法有效地增强了JPEG2000压缩图像沿边缘的正则性,提高了图像的主客观质量,图像峰值信噪比平均提高0.52dB.JPEG2000 compressed image at middle-low bit-rate shows obvious ringing effects,which severely depresses the image visual quality.In order to resolve this problem,on the base of the iterative projection onto convex sets theory,a JPEG2000 image reconstruction method was presented by analysis of the sparse data recovery mechanism in transform-domain using iterated denoising.This algorithm kept the non-zero coefficients in the wavelet domain unchanged and recovered the others coefficients using iterative denoising.Experimental results show that the proposed method is effective to enhance the regularity of JPEG2000 compressed image along the edge and to improve subjective and objective image quality,and the average peak signal to noise ratio is improved by 0.52 dB.

关 键 词：图像压缩 图像质量 JPEG2000 稀疏重建 去噪 小波变换 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]