航拍图像暗通道先验去雾算法速度改进

针对暗通道先验去雾算法复杂程度较高, 利用引导滤波精细化大气透射率图层时间较长的问题, 提出一种用中值滤波精细化透射率图层的算法改进航拍图像去雾速度. 改进算法定义了一种算法简单且具有边缘保护效果、与滤波窗口无关、 时间复杂度为O(1)的中值滤波器, 对云雾均匀的输入图像, 用中值滤波较好地模糊了计算暗通道图层而产生的块状处理结果. 通过计算机编码并采用无参考的客观图像质量评价方法比较算法改进前后的去雾图像效果, 定量分析与实验结果表明, 当原始图像云雾分布较均匀时, 用中值滤波算法时间复杂度低, 相比引导滤波更易实现, 既能节约去雾时间, 又能实现图像平滑处理.

Speed Improvement of Dark Channel Prior Fog Removal Algorithm for Aerial Images

Aiming at the problem of the complexity of dark channel prior fog removal algorithm, and using guided filtering to refine the atmospheric transmittance layer for a long time, we proposed an algorithm to refine transmittance layer by the median filtering to improve the fog removal spe ed of aerial image. The improved algorithm defined a simple median filter with edge protection effect, independent of the filtering window and time complexity of O(1). The blocky processing result generated by calculating the dark channel layer was better blurred by the median filter for the uniform cloud input image. The effect of fog removal image before and after improvement of the algorithm was compared by computer encoding and objective image quality assessment method without reference. The quantitative analysis and experimental results show that the median filtering algorithm is easier to implement than the guided filtering when the original image is evenly distributed. It can not only save fog removal time, but also realize image smoothing.