关键词: 图像去雾, 暗通道先验, 均值滤波, 引导滤波

Abstract: Dark channel prior often gives a smaller estimation value of transmission in bright areas and sky regions, resulting in brightness dim and color distortion of restored image. So this paper proposes a single image dehazing method. Firstly, a smooth dark channel is defined to describe the central tendency of three color channel values when the mean filter is used to calculate the dark channel instead of the minimal filtering. The smoothing transmission is calculated roughly by mean filter, and then is refined through guided filter. The atmospheric light is estimated from the most haze-opaque pixel. The method avoids to the halo effect and black spot. The values of image luminance and atmospheric light are compared. When in a range of greater than or less than atmosphere bright, the pixel value is seen as a point of light areas, and the transmittance is corrected. The method makes the obtained transmission more precise, details of restored image more distinct. The experimental results show that the proposed algorithm can effectively solve the problem of the image distortion in the large and bright areas, and the restored image has high brightness and contrast.

Key words: image dehazing, dark channel prior, mean filter, guided filter