关键词: 雾天交通图像, 图像增强, 大气物理散射模型, 暗原色先验, 偏微分方程

Abstract: A new method for single hazy traffic image enhancement is proposed. The relationships between original image gradient field and ideal image gradient field are obtained by calculating gradient on both sides of atmospheric scattering physical model, then the recovery of the ideal image is turned into extremum problem of functional about gradient energy, finally the partial differential equation model is obtained through variational?method. Using the dark channel prior, two transmission maps based patch dark channel and point dark channel can be estimated respectively, then each of them are processed by fast wavelet transform. Afterwards, the high-frequency component which comes from the transmission map of point dark channel and low-frequency component which comes from the transmission map of patch dark channel are extracted. Finally, a high quality ideal image can be obtained by solving the Euler equation by finite difference method. A comparative experiment with a few other state of the art algorithms shows that the algorithms can improve the quality of hazy image effectively, especially for hazy image which slants dark.

Key words: hazy traffic image, image enhancement, image degradation model, dark channel prior, partial differential equation