Whether & gt& gttype edge can display its function content, and if so, it is not a built-in function.

If the edge function is not used, the function of the edge function can be realized according to the LOG operator (edge detection algorithm).

Steps to realize the LOG operator: (1)? Smoothing filtering with a two-dimensional Gaussian filter; ? (2)? Two-dimensional Lapp operator is used to enhance images. ? (3)? Edge detection based on zero crossing of second derivative.