Introduction - If you have any usage issues, please Google them yourself
A gray image edge preserving smoothing filter code. 5* 5 pixel region, to include the center point (I, J) of the vertical and horizontal direction, and the oblique 45 degree angle direction, the middle of the 3 x 3, a total of 9 neighborhood template, and the computation of standard deviation of the template block minimum, take it as the mean filter template.