canny边缘检测一共四个部分：



　　1.对原图像高斯平滑



　　2.对高斯平滑后的图像进行sobel边缘检测。这里需要求横的和竖的还有联合的，所以一共三个需要sobel边缘检测图像。



　　3.对联合的sobel检测图像进行非极大抑制



　　4.连接边缘点并进行滞后阈值处理。-canny edge detection total of four parts:



1. Gaussian smoothing the original image



2. After the images were Gaussian smoothing sobel edge detection. Here and there on request transverse vertical joint, so a total of three needs sobel edge detection image.



3. sobel combined detection image greatly suppress non-



4. Connect the edge point and hysteresis thresholding.