#include <opencv2/opencv.hpp>
using namespace cv;
int main()
{
    VideoCapture capture(0);
    Mat edges;
    while (1)
    {
        Mat frame;        
        capture>>frame;
        cvtColor(frame,edges,COLOR_BGR2GRAY);
        blur(edges,edges,Size(7,7));
        Canny(edges,edges,0,30,3);
        imshow("被canny后的视频",edges);
        if(waitKey(30)>=0) break;
    }

    return 0;

}

#include <opencv2/opencv.hpp>
using namespace cv;
int main()
{
    Mat edges;
    Mat frame;        
    frame=imread("/home/yu/Desktop/ex/2.jpg",1); 
    cvtColor(frame,edges,COLOR_BGR2GRAY);
    blur(edges,edges,Size(7,7));
    Canny(edges,edges,0,30,3);
    imshow("被canny后的图片",edges);
    waitKey(0);
    return 0;
}