中值滤波是对一个滑动窗口内的诸像素灰度值排序，用其中值代替窗口中心象素的原来灰度值，它是一种非线性的图像平滑法，它对脉冲干扰级椒盐噪声的抑制效果好，在抑制随机噪声的同时能有效保护边缘少受模糊-Median filter is a sliding window from inside the gray value pixel sequencing, using a window center pixel value to replace the original gray value, it is a non-linear image smoothing method, its pulse-grade salt and pepper noise interference inhibition effective in suppressing random noise at the same time can effectively protect the edge of less fuzzy