opencv读取USB摄像头程序图像显示不连续

#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>

int main()
{
	// Open the video file
       // cv::VideoCapture capture("E:\UAV Detection\video\video.mp4");
        cv::VideoCapture capture(0);
	// check if video successfully opened
	
	if (!capture.isOpened())
		return 1;

	// Get the frame rate
	double rate= capture.get(CV_CAP_PROP_FPS);

	bool stop(false);
	cv::Mat frame; // current video frame
	cv::namedWindow("Extracted Frame");

	// Delay between each frame
	// corresponds to video frame rate
	int delay= 1000/rate;

	// for all frames in video
	while (!stop) {

		// read next frame if any
		if (!capture.read(frame))
			break;

		cv::imshow("Extracted Frame",frame);

		// introduce a delay
		// or press key to stop
		if (cv::waitKey(delay)>=0)
		//if (cv::waitKey(30) >= 0)
				stop= true;
	}

	// Close the video file
	capture.release();
}  
#include <iostr