Mat frame, after;
    VideoCapture cap(0);                    // open the default camera
    if (!cap.isOpened())                    // check if we succeeded
    {
        return -1;
    }

    cap >> frame;

    imshow(NAZWA_OKNA, frame);
    int x = 6;
    boxFilter(frame, after, frame.depth(), Size(x, x));
    imshow(NAZWA_OKNA_2, after);
    for (;;)
    {
        if (waitKey(30) >= 0) break;
    }