Fog Image Enhancement Algorithm

Because of the atmosphere scattering phenomenon, weather degraded images captured in fog suffer from poor contrast and low visibility. This significantly affects the traffic systems and outdoor visual systems. Hence, it is imperative to enhance the low-contrast images degraded by fog.There are two ways to enhance the low-contrast images: image enhancement and image restoration. The research in this issue is mainly about the methods of image enhancement.The work in this paper is aiming at the characteristic of scene depth variations on fog images. Adaptive histogram equalization is used to enhance the local information of images. Methods including local HE, POSHE, interpolating HE, generalized HE are deeply analyzed in detail, and their applications on fog images, and then based on the hue preservation principle, images are transformed both in the RGB and CMY color spaces; the enhancement methods in gray scale are generalized to the color space.Theoretical analysis and experimental results demonstrate that, methods used in this paper are effective for contrast enhancement of fog-degraded images, and can be applied to the practical situations. This research will be a solid base for the further investigations on contrast enhancement of fog-degraded images...