说明：  该程序为中值滤波程序，选取的滤波窗口为3*3方形滤波窗口，如有需要可手动修改程序，扩大窗口范围以获得更好的效果。
(The program for the median filtering process, the filter window is 3* 3 square filter window, you can manually modify the program if necessary, to expand the scope of the window to get a better effect.)