一种改进的基于暗通道先验的图像去雾算法  

An Improved Haze Removal Algorithm Based on the Dark Channel Prior

作　　者：杨旭 任世卿[1] 苗芳 YANG Xu;REN Shiqing;MIAO Fang(Shenyang Ligong University,Shenyang,110159,China;Liaoning Provincial Institute of Measurement,Shenyang 110004,China)

机构地区：[1]沈阳理工大学信息科学与工程学院,沈阳110159 [2]辽宁省计量科学研究院,沈阳110004

出　　处：《沈阳理工大学学报》2019年第6期15-21,共7页Journal of Shenyang Ligong University

摘　　要：雾霾天气造成图像采集设备无法获取足够清晰的图像,为之后获取图像中的有效信息带来很大困难,由此对图像进行去雾处理显得尤为重要。暗通道先验去雾算法对大多数自然场景图像有着较好的去雾效果,但暗通道先验规律并不适用于天空区域,造成去雾后图像的天空区域颜色失真严重。针对这一问题,本文提出一种基于天空区域分割和HSI颜色空间模型的暗通道先验去雾算法。首先,运用RETINEX算法增强有雾图像的边缘信息,对增强后的图像进行canny边缘提取,同时结合形态学方法精确分割出天空区域;其次,在天空区域选取准确的大气光值,将图像中的天空区域转换到HSI颜色空间进行处理,并只对亮度分量进行改进的暗通道去雾处理,保留原图像色调和饱和度信息;最后,对非天空区域进行暗通道去雾,完成整幅图像的去雾。实验结果显示,该方法很好地解决了天空区域颜色失真和噪声增加的问题,使去雾后的图像更加清晰自然。The haze weather causes problems for the image acquisition device to obtain a sufficiently clear image,which makes it difficult to obtain effective information of the image,and thus haze removal is particularly important.The haze removal algorithm based on the dark channel prior has a good dehazing effect on most natural scene images,but this method does not apply to the sky region,resulting in severe color distortion in the sky region after dehazing.To solve this problem,a dark channel prior dehazing algorithm based on sky region segmentation and HSI color space model is proposed in this paper.Firstly,the edge information of the haze image is enhanced by the RETINEX algorithm,and the enhanced image is extracted with canny for edge extraction,and the sky region is accurately segmented by combining the morphological methods.Secondly,a more accurate atmospheric light value A is selected in the sky region,and the sky region in the image is converted into the HSI color space for processing,and only the dark component dehazing method in which the luminance component I is improved is processed,so that the original image tone information and saturation are obtained.Finally,the non-sky area is dehazed by the dark channel algorithm to complete the dehazing of the entire image.The experimental results show that the problem of color distortion and noise increase in the sky area is well solved by this method,which makes the image after defogging more clear and natural.

关 键 词：去雾 暗通道先验 RETINEX算法 HSI颜色空间模型 

分 类 号：TN911[电子电信—通信与信息系统]