opencv - 显示捕获的视频

Question

在 opencv2.2 visual c++ express 2010 中，灰屏显示为输出而不是实际的相机输入。是因为任何 dll 文件吗？

我正在尝试执行一个简单的 opencv 程序来显示捕获的视频源，但得到一个灰色窗口作为输出。

int main(void) {

CvCapture* capture = cvCaptureFromCAM (CV_CAP_ANY);
if( !capture ) {
    fprintf( stderr, "ERROR: capture is NULL \n");
    getchar();
    return -1;
}
// create a window in which the capture images will be presented
cvNamedWindow("mywindow", CV_WINDOW_AUTOSIZE);
// show the image captured from the camera in the window and repeat
while (1) {
    // get one frame
    IplImage* frame = cvQueryFrame (capture);
    if (!frame) {
        fprintf( stderr, "ERROR: frame is null...\n");
        getchar();
        break;
    }
    cvShowImage("mywindow", frame);
    // do not release the frame

    // terminate
    if ((cvWaitKey(10) & 255) == 27) break;
}

// release the capture device
cvReleaseCapture (&capture);
cvDestroyWindow("mywindow");

return EXIT_SUCCESS;
}