Introduction - If you have any usage issues, please Google them yourself
Canny goal is to find an optimal edge detection algorithm, the optimal edge detection means:
Good test- algorithm can identify as many as possible of the actual edge image.
Good Location- identifies the edge as much as possible with the actual edge of the actual image as close as possible.
Minimum response- edges in the image can only be identified once, and there may be noise in the image should not be identified as edges.