In order to deal with the problems that dense fog influenced the image quality, a dense fog image defogging algorithm was put forward. In this paper, the physical model of imaging in fog was simplified，and the concept of fog concentration factor was put forward. The relationship between visibility and fog concentration factor was established when this paper analyzed the factors affecting the concentration of fog. By seeking the value of the fog concentration factor and Estimating the value of atmospheric light using guided filtering, the dense fog image could be recovered. Experimental results showed that after the algorithm the image brightness is higher, the image contrast and resolution is higher, and the overall visual perception of the image is better.
