Assertion failed (size.width>0 && size.height>0)

Question

I\'m using Visual Studio Express 2013 with OpenCV 2.4.7, following this tutorial.

I have spent hours searching the web for solutions, including all of t

Answer 1

I tried your code and for me it works (it visualizes the current webcam input)!
I ran it on Visual Studio 2012 Ultimate with OpenCV 2.4.7.
...
The error occurs because the image is empty, so try this:

while (true) {
    cap >> image;

    if(!image.empty()){
        imshow("window", image);
    }

// delay 33ms
waitKey(33);        
}

Maybe the first image you receive from your webcam is empty. In this case imshow will not throw an error. So hopefully the next input images are not empty.

Answer 2

Do this:

VideoCapture cap;
cap.set(CV_CAP_PROP_FRAME_WIDTH, 640);
cap.set(CV_CAP_PROP_FRAME_HEIGHT, 480);
int camOpen = cap.open(CV_CAP_ANY);

Or you can try changing this:

while (true) {
        cap >> image;

        imshow("window", image);

    // delay 33ms
    waitKey(33);        
    }

to

try
{
     cap >> image;
     imshow("window", image);
     waitKey(33); 
}
catch (Exception& e)
{
    const char* err_msg = e.what();
    std::cout << "exception caught: imshow:\n" << err_msg << std::endl;
}

Answer 3

int i=0;

while(i<4)

{

VideoCapture cap(0); // force camera to open 4 tiMEs

i++;

}

waitKey(5000); 
VideoCapture cap(0);
int camOpen = cap.open(CV_CAP_ANY);

namedWindow("window", CV_WINDOW_AUTOSIZE);

while (true) {
    cap >> image;

    imshow("window", image);
waitKey(33);        
}

Do this it will work for you for sure.