中文说明： Canny边缘检测算子是John F. Canny于 1986 年开发出来的一个多级边缘检测算法。步骤是去噪声、寻找图中的亮度梯度、在图像中跟踪边缘。算法过程中涉及一部分参数，大部分的代码参数都是固定的，这个的参数是可调的。
English Description：
Canny edge detection operator is a multi-level edge detection algorithm developed by John F. canny in 1986. The steps are denoising, finding the brightness gradient in the image and tracking the edge in the image. Some parameters are involved in the process of the algorithm, most of the code parameters are fixed, and the parameters of this algorithm are adjustable.