基于颜色平衡和多尺度融合的水下图像增强  

Underwater image enhancement based on color balance and multi-scale fusion

作　　者：胡振宇 陈琦[1,2] 朱大奇 HU Zhenyu;CHEN Qi;ZHU Daqi(Shanghai Engineering Research Center of Intelligent Maritime Search&Rescue and Underwater Vehicles,Shanghai Maritime University,Shanghai 201306,China;School of Mechanical Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海海事大学智能海事搜救与水下机器人上海工程技术研究中心,上海201306 [2]上海理工大学机械工程学院,上海200093

出　　处：《光学精密工程》2022年第17期2133-2146,共14页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.51975565,No.52127813);上海市科技创新行动计划资助项目(No.20dz1206700);辽宁省自然科学基金资助项目(No.2020-KF-22-12)。

摘　　要：水体对光有吸收和散射作用,导致水下图像出现颜色偏差、细节模糊、对比度低等问题。提出了一种基于颜色平衡和多尺度融合的水下图像增强算法,采用一种颜色平衡方法来校正图像颜色,将颜色平衡处理后的图像从RGB空间转换到Lab空间,用限制对比度自适应直方图均衡化方法处理L通道来增强对比度,且对比度增强后将图像转换回RGB空间。最后,对颜色校正后的图像和对比度增强后的图像按权重图进行多尺度融合。图像增强处理后,在视觉效果和图像质量2个方面比较该算法和其他算法对图像的增强效果。实验结果表明:该算法能够去除水下图像的色偏,提高图像的清晰度和对比度,图像的信息熵、UIQM及UCIQE较原始图像分别提高了5.2%,1.25倍和30.8%。该算法能够有效改善水下图像的视觉质量。This study proposes an underwater enhancement algorithm based on color balance and multiscale fusion to address the color deviation,detail blur,and low contrast of underwater images caused by water absorbing and scattered light.A color balance method was used to correct color.Then,the colorcorrected image was converted from the RGB space to Lab space,and the L-channel was processed with the contrast limited adaptive histogram equalization method to enhance the contrast.Subsequently,the image was converted back to the RGB space.Finally,the multi-scale fusion method was used to fuse the color-corrected image with the contrast-enhanced image according to weight maps.After image enhancement,the enhancement effect of the proposed algorithm was compared with that of other algorithms in terms of visual effect and image quality evaluations.Experiments show that the proposed algorithm can remove color deviation of an underwater image,as well as improve its clarity and contrast.Compared with the original image,the entropy,UIQM,and UCIQE of the processed image increase by at least 5.2%,1.25 times,and 30.8%,respectively,thereby proving that the proposed algorithm can effectively improve the visual quality of underwater images.

关 键 词：图像增强 颜色平衡 多尺度融合 自适应直方图均衡化 

分 类 号：TP394.1[自动化与计算机技术—计算机应用技术] TH691.9[自动化与计算机技术—计算机科学与技术]