改进型大气散射模型下的双光幕约束雾图复原算法  

Double light curtain-constrained hazy image restoration algorithm based on improved atmospheric scattering model

作　　者：杨燕[1] 张帅 舒仝 YANG Yan;ZHANG Shuai;SHU Tong(School of Electronic and Information Engineering,Lanzhou Jiao Tong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学电子与信息工程学院,兰州730070

出　　处：《北京航空航天大学学报》2024年第12期3632-3644,共13页Journal of Beijing University of Aeronautics and Astronautics

基　　金：国家自然科学基金(61561030,62063014);甘肃省高等学校产业支撑计划项目(2021CYZC-04);兰州交通大学研究生教改项目(JG201928);甘肃省教育厅优秀研究生“创新之星”项目(2022CXZX-548)。

摘　　要：当雾霾退化场景处于光照不均匀的条件下时,部分场景细节不仅会由于雾气遮盖导致可见度降低,同时会因为光照阴影使得部分区域不可见。针对这一问题,提出一种基于改进型大气散射模型的双光幕边界约束的雾天图像复原算法。分析传统大气散射模型的成像原理,利用其退化机理结合Retinex理论对模型进行改进;引入均值不等关系与高斯衰减函数,通过预估特征值的方法对大气光幕进行估计,并设定上下边界对其进行约束;依照改进型大气散射模型求取场景入射光,并利用亮通道先验求取有雾图像亮通道对场景入射光进行补偿;改进局部大气光的获取方法,提出基于中通道的局部大气光估计方法,结合所求大气光幕与场景入射光代入改进型大气散射模型获得无雾图像,并使其与图像纹理层进行融合得到最终的复原结果。根据对实验结果的定性与定量分析,所提算法不仅可以有效复原出场景光照不均的有雾图像,针对其余场景下的雾霾场景也可得到较好的复原效果,且复原场景清晰,明亮度适宜。When a haze-degraded scene is under uneven lighting conditions,some scene details will be less visible due to hazy obscuration and light shadows.To address this issue,a hazy image restoration algorithm with double light curtain boundary constraints based on an improved atmospheric scattering model was proposed.The imaging principle of the conventional atmospheric scattering model was analyzed,and the model was improved by using its degradation mechanism combined with the Retinex theory.The mean inequality relation and Gaussian decay function were introduced to estimate the eigenvalue of the atmospheric light curtain.In addition,the upper and lower boundaries were set to constrain the estimated values.The scene-incident light was obtained by an improved atmospheric scattering model,which was compensated by using the bright channel of the hazy image through the bright channel prior method.The method of local atmospheric light acquisition was improved.A mid-channel-based local atmospheric light estimation method was proposed.The estimated atmospheric light curtain and scene-incident light were introduced into an improved atmospheric scattering model to obtain a hazy-free image.Then,the hazy-free image was fused with the image texture layer to obtain the final restored image.According to the subjective and objective analyses of the experimental results,the proposed algorithm can not only effectively restore the hazy images with uneven scene illumination but also get a better restoration effect for the haze scenes.The restored scene is clear,and the brightness is moderate.

关 键 词：雾图复原 大气散射模型 RETINEX理论 大气光幕 场景入射光 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]