opencv - cvCaptureFromCAM(CV_CAP_DSHOW) capture blank frame

问题

I am using OpenCV 2.1 and Visual Studio 2008 in Windows. I am trying to grab the frames from CCD camera and want to display on Windows. Camera is with PAL format. Camera is detecting but showing the blank grey screen.

I found many post related to blank screen but no one is work in my case. So post I post this question.

Below is my code:

#include "stdafx.h"
#include "cv.h"
#include "cxcore.h"
#include "highgui.h"
#include <iostream>

int main(int argc, char* argv[])
{   
    cvNamedWindow( "mywindow", CV_WINDOW_AUTOSIZE );

    CvCapture* capture = cvCaptureFromCAM(CV_CAP_DSHOW);

    if ( !capture ) {
        fprintf( stderr, "ERROR: capture is NULL \n" );
        getchar();
        return -1;
    }

    while ( 1 ) {
        IplImage* frame = cvQueryFrame( capture );

        if ( !frame ) {
            fprintf( stderr, "ERROR: frame is null...\n" );
            getchar();
            break;
        }
        else
        {
            fprintf( stderr, "Size of camera frame %d X %d\n",frame->width,frame->height );
        }

        cvShowImage( "mywindow", frame );

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

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

    return 0;
}

Above code return frame size 320 X 240 but blank screen.

Code is working fine for usb webcam with code CvCapture* capture = cvCaptureFromCAM(1);

I am using Avermedia Gold Camera Card on my board. So Do I need SDK to use this camera or is there any option to use CCD camera??

Driver is installed correctly and check with EzCaptureVC application.

回答1:

OpenCV needs to support your camera else there's no guarantee its going to work: check the compatibility list.

Also 2.1 it's very outdated. I suggest you try again with the 2.3.1 since there has been some improvements in this area.

来源：https://stackoverflow.com/questions/10432345/opencv-cvcapturefromcamcv-cap-dshow-capture-blank-frame

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OpenCV

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