Single Image Haze Removal with Improved Atmospheric Light Estimation

Abstract

A novel method for atmospheric light estimation has been proposed in this paper. The new estimation method, called Estimation Based on Patch Size Adjustment (PSA), firstly segments the sky region of dark channel through threshold segmentation method and then adaptively adjusts the patch for dark channel until the estimated atmospheric light is right in the segmented sky region. Experimental results show that this method is effective even when the intensity of some scene objects is inherently higher than the atmospheric light and no shadow is cast near them. However, PSA spends a lot of time on adjustment. In order to improve the time efficiency, another simplified method, called Estimation Based on Sky Region Segmentation (SRS), is proposed by directly estimating the atmospheric light in the segmented sky region. The test results show SRS is almost as good as PSA on haze removal effect. Both methods have advantages on improving visual effect and objective indicators of the haze-free images.