缓解平滑区域光晕和偏色失真的图像去雾算法  

Image Dehazing Algorithm for Relieving Halo Effect and Color Distortion in Smooth Regions

作　　者：宋传鸣[1,2] 唐媛 乔明泽 刘霜 刘丹 Song Chuanming;Tang Yuan;Qiao Mingze;Liu Shuang;Liu Dan(School of Computer and Information Technology,Liaoning Normal University,Dalian 116029;Provincial Key Laboratory for Computer Information Processing Technology,Soochow University,Suzhou 215006;School of Digital Arts and Design,Dalian Neusoft University of Information,Dalian 116023)

机构地区：[1]辽宁师范大学计算机与信息技术学院,大连116029 [2]苏州大学江苏省计算机信息处理技术重点实验室,苏州215006 [3]大连东软信息学院数字艺术与设计学院,大连116023

出　　处：《计算机辅助设计与图形学学报》2022年第6期953-969,共17页Journal of Computer-Aided Design & Computer Graphics

基　　金：辽宁省自然科学基金(20180550570);辽宁省高等学校创新人才支持计划([2018]478第64号).

摘　　要：针对基于暗通道先验的去雾算法在平滑区域产生光晕和偏色失真的问题,提出一种双边滤波引导同态滤波的去雾算法.首先,构建一种以原始像素值与大气光值的差为正比例系数、以透射率为反比例系数的非线性拉伸模型,用于表征各颜色分量在去雾前后的对比关系;然后,采用双边滤波引导的空间域同态滤波,把粗透射率分解为大气光分量和场景目标反射分量;最后,以前景区域面积比为自变量,定义一种自适应加权函数,对大气光分量和反射分量进行线性加权以生成精细透射率,进而利用暗通道先验模型完成去雾.采用O-HAZE和RESIDE数据集的真实含雾图作为测试数据,通过UCIQE,FADE,SSIM,NIQE和色彩还原度客观评价指标进行对比,所提算法的评价结果比典型算法平均提高了21.68%.结果表明,所提算法能够有效地避免大面积平滑区域的偏色失真以及景物边缘、轮廓处的光晕和伪边缘效应,取得更高的主客观质量.Aiming to solve the problem that the dehazing algorithm based on the dark channel produces halo effect and color distortion in smooth region,a novel dehazing algorithm is proposed using bilateral filter guided homomorphic filtering.Firstly,a nonlinear stretch model is constructed to characterize the contrast relationship among each color component before and after dehazing.The model is proportional to the difference between the original pixels and the atmospheric light value while inversely proportional to the transmittance.Secondly,the coarse transmittance map is decomposed into an atmospheric light component and a reflection component by use of the bilateral filter guided spatial homomorphic filtering.Finally,an adaptive function is defined,taking the ratio of the foreground area as a variable.It is used to calculate a refined transmittance map by linearly weighting the atmospheric light component and the reflection component,and then employed to accomplish the dehazing with the dark channel prior model.The real foggy images in O-HAZE and RESIDE datasets is used as the test data,and the UCIQE,FADE,SSIM,NIQE,and hue restoration ability are adopted as the objective evaluation matrics.The evaluation scores of the proposed algorithm increase by 21.68%on average,compared with those of the state-of-art algorithms.The results show that the proposed algorithm is able to effectively avoid the color distortion in large smooth area,as well as the halo&fake edge effects at the edges and contours,achieves higher subjective and objective quality.

关 键 词：图像去雾 暗通道先验 空间域同态滤波 双边滤波 自适应线性加权 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]