光子学报, 2012, 41 (2): 200, 网络出版: 2012-03-09
基于Retinex理论JPEG2000压缩图像增强方法
Enhancement Method of JPEG2000 Compression Image Based on Retinex Theory
图像增强 Retinex理论 JPEG2000压缩 小波变换 亮度量化表 Image enhancement Retinex theory JPEG2000 DWT Iillumination quantity table
摘要
在增强压缩图像过程中,采用传统图像增强方法存在细节恢复困难,易产生块状效应等局限性,针对此问题,本文将Retinex理论引入JPEG2000压缩框架中,提出一种新的JPEG2000压缩图像增强方法.它将小波变换后的低频系数看作入射光分量,高频系数看作反射光分量,通过对低频系数进行两次非线性映射,来调整场景光照的动态范围; 通过调整高频系数,提高对比度,实现图像细节的整体拉升; 通过判断各子块的活动性,自适应来修改亮度量化表,达到可以保留更多的细节,抑制块状效应的目的.实验结果表明,该算法在增强效果、压缩质量等方面都有着较好的优势.
Abstract
In the process of enhancing the image compression, the traditional image enhancement method has some difficulties in the details recovery and generates blocky effect easily. A new method of JPEG2000 compressed image enhancement is proposed by applying the thory of Retinex into JPEG2000 compact frame. The dynamic range of scene illumination is adjusted through two low-frequency coefficients non-linear mapping with the low frequency coefficients as the wavelet transform and the high-frequency coefficients as the reflected light. By adjusting the high frequency coefficient, image contrast is enhanced,so that the image detail is trended overall. Then illumination quantity table is modifyed and more details is retained and block effect is controled through judging activities of each sub-block and adaptive quantization.The experimental results show that this algorithm performed well in the reinforcing effect and the compressed quality,etc.
储昭辉, 汪荣贵, 张璇, 张新龙. 基于Retinex理论JPEG2000压缩图像增强方法[J]. 光子学报, 2012, 41(2): 200. CHU Zhao-hui, WANG Rong-gui, ZHANG Xuan, ZHANG Xin-long. Enhancement Method of JPEG2000 Compression Image Based on Retinex Theory[J]. ACTA PHOTONICA SINICA, 2012, 41(2): 200.