中文说明：只是用canny算子来实现图像边缘检测的算法，用原代码来实现canny算子5个步骤。Canny算法实现：用高斯滤波器平滑图像（在调用Canny之前自己用blur平滑）用一阶偏导的有限差分来计算梯度的幅值和方向．对梯度幅值应用非极大值抑制 ．用双阈值算法检测和连接边缘．
English Description：
Just using the algorithm to realize image edge detection of canny operator, using the original code to achieve the canny operator 5 steps. Canny algorithm: image smoothing with Gaussian filter (before calling the Canny themselves use blur to smooth) used to calculate the first order partial derivative of a finite-difference gradient of magnitude and direction. The gradient magnitude using non-Maxima suppression. Connected with the detection and dual-threshold algorithm edges.