Introduction - If you have any usage issues, please Google them yourself
The Canny algorithm contains many parameters that can be adjusted, which will affect the time and effect of the algorithm's computation.
The size of the gaussian filter: the smoothing filter used in the first step will directly affect the results of the Canny algorithm. Smaller filters also produce less blurring, which can detect smaller, more variable lines. The larger filter produces more fuzzy effects, and the larger image area is painted as a specific point color value. The result is more useful for detecting large, smooth edges, such as the edge of a rainbow.
Threshold: using two thresholds is more flexible than using a threshold, but it still has a common problem with thresholds. The set threshold is too high and may miss important information; If the threshold is too low, it will be important to see the details. It is difficult to give a generic threshold for all images. There is currently no proven implementation method.