opencv 启动摄像头

#include   
#include   
#include   
  
using namespace cv;  
  
  
int main()  
{  
    VideoCapture cap(0);  
    if(!cap.isOpened())  
    {  
        return -1;  
    }  
    Mat frame;  
    Mat edges;  
  
    bool stop = false;  
    while(!stop)  
    {  
        cap>>frame;  
        cvtColor(frame, edges, CV_BGR2GRAY);  
        GaussianBlur(edges, edges, Size(7,7), 1.5, 1.5);  
        Canny(edges, edges, 0, 30, 3);  
        imshow("当前视频",edges);  
        if(waitKey(30) >=0)  
            stop = true;  
    }  
    return 0;  
}