针对雾天下拍摄图像的退化现象，提出了一种景物影像清晰化的方法。该方法不需要依据大气模型，即可直接对景物的细节信息进行增强处理，并可用移动模板对不同深度的场景进行分割，以对模板中的区域进行块重叠直方图均衡化处理。为了能在对景物细节信息进行增强的同时，避免天空噪声的影响，可根据图像的灰度分布特性，求出天空区域灰度的最佳近似正态分布，再由这个近似正态分布估计来得到分割天空区域的灰度值分布范围，以增强景物细节信息。实验结果表明，该算法能有效地改善雾天下图像的退化现象和提高图像的清晰度。

According to the effect of fog from images, a new method for enhancing images taken in fogs is proposed in this paper. It dose not need atmospheric model and just performs on the image, directly enhancing details of the scene in the image. A moving mask is adopted to segment scene at different depth, then each pixel in the mask is processed using block-overlapped histogram equalization. At the same time the influence of mask's size also is discussed in this paper. Though the enhance operation will improve visual result, it also will bring noise amplification in sky region. To restrain the adverse effect, the sky region should firstly be segmented before enhance operate. Using optimal normal distribution to approach the characteristic of image gray distribution, then by the estimated distribution, the range of pixel value in the sky region can be got. By the information, the sky region can be segmented from the image. Experiments show that this algorithm can efficiently improve the degradation of image and enhance the clearness of image.