Abstract: When images are shot in fog circumstances, the color and contrast of fog images appear degrade phenomenon.In order to improve the quality of fog image, this paper proposed a fog image enhancement method based on improved multi-scale Retinex algorithm. Firstly, the dynamic range of image was compressed by the power transform, and then nonlinear transform was used to suppress the high light area of image,finally the unsharp mask filtering was used to eliminate fuzzy to enhance the detail information of fog image,and a few fog images were used to test the performance of the proposed algorithms. The simulation results show that the proposed algorithm solves the shortcomings of traditional Retinex algorithms, accelerates the speed of fog image enhancement, and the fog image is more clearly, so it can obtain better visual effect

Key words: Fog image, Image enhancement, Retinex, Defog