Haze removal using scale adaptive dark channel prior

In fog and haze weather conditions, scattering of atmospheric particles greatly reduces the outdoor visibility. Images captured by vision system suffer from serious degradation. Haze removal using the dark channel prior is considered to be a good solution due to its advantage of simple implementation and pleasing result with little constraint. While the selection of scale(radius of patch size) determines quality of the recovered image. For different scenes, there is no generally applicable scale. To solve this problem, in this paper, a scale adaptive method was proposed. It adjusted the range of scale adaptively according to features of color and edge, and get the pixel-level scale of dark channel. Proposed method has both advantage of little color distortion and little halo artifacts. In addition, an improved method of atmospheric light estimation was proposed. By this approach, the estimation point robustly fell into the background region, and that was physically sound. Experimental results on a variety of outdoor hazy images demonstrate that the proposed method is general applicable. The method also achieves pleasing results of haze removal with good color atmosphere and higher contrast.