int numberOfDisparities = 16;
    int SADWindowSize = 9;

    Ptr<StereoSGBM> sgbm = StereoSGBM::create(0, numberOfDisparities, SADWindowSize);

    ...
    ...

    int cn = img1.channels();
    int sgbmWinSize = SADWindowSize > 0 ? SADWindowSize : 3;
    sgbm->setBlockSize(sgbmWinSize);

    sgbm->setP1(8 * cn*sgbmWinSize*sgbmWinSize);
    sgbm->setP2(32 * cn*sgbmWinSize*sgbmWinSize);
    sgbm->setPreFilterCap(31);
    sgbm->setMinDisparity(0);
    sgbm->setNumDisparities(numberOfDisparities);
    sgbm->setUniquenessRatio(10);
    sgbm->setSpeckleWindowSize(100);
    sgbm->setSpeckleRange(32);
    sgbm->setDisp12MaxDiff(1);
    sgbm->setMode(StereoSGBM::MODE_SGBM);

    sgbm->compute(img1, img2, disp);

    disp.convertTo(disp8, CV_8U, 255 / (numberOfDisparities*16.));

    cv::cvtColor(disp8, disparityMap, cv::COLOR_GRAY2BGR);

    namedWindow("left image", 1);
    imshow("left image", img1);

    namedWindow("right image", 1);
    imshow("right image", img2);

    namedWindow("disparity", 0);
    imshow("disparity", disparityMap);