Method threshold

deps/opencv/modules/imgproc/src/thresh.cpp:710–788

}

double cv::threshold( InputArray _src, OutputArray _dst, double thresh, double maxval, int type )
{
    Mat src = _src.getMat();
    bool use_otsu = (type & THRESH_OTSU) != 0;
    type &= THRESH_MASK;

    if( use_otsu )
    {
        CV_Assert( src.type() == CV_8UC1 );
        thresh = getThreshVal_Otsu_8u(src);
    }

    _dst.create( src.size(), src.type() );
    Mat dst = _dst.getMat();

    if( src.depth() == CV_8U )
    {
        int ithresh = cvFloor(thresh);
        thresh = ithresh;
        int imaxval = cvRound(maxval);
        if( type == THRESH_TRUNC )
            imaxval = ithresh;
        imaxval = saturate_cast<uchar>(imaxval);

        if( ithresh < 0 || ithresh >= 255 )
        {
            if( type == THRESH_BINARY || type == THRESH_BINARY_INV ||
                ((type == THRESH_TRUNC || type == THRESH_TOZERO_INV) && ithresh < 0) ||
                (type == THRESH_TOZERO && ithresh >= 255) )
            {
                int v = type == THRESH_BINARY ? (ithresh >= 255 ? 0 : imaxval) :
                        type == THRESH_BINARY_INV ? (ithresh >= 255 ? imaxval : 0) :
                        /*type == THRESH_TRUNC ? imaxval :*/ 0;
                dst.setTo(v);
            }
            else
                src.copyTo(dst);
            return thresh;
        }
        thresh = ithresh;
        maxval = imaxval;
    }
    else if( src.depth() == CV_16S )
    {
        int ithresh = cvFloor(thresh);
        thresh = ithresh;
        int imaxval = cvRound(maxval);
        if( type == THRESH_TRUNC )
            imaxval = ithresh;
        imaxval = saturate_cast<short>(imaxval);

        if( ithresh < SHRT_MIN || ithresh >= SHRT_MAX )
        {
            if( type == THRESH_BINARY || type == THRESH_BINARY_INV ||
               ((type == THRESH_TRUNC || type == THRESH_TOZERO_INV) && ithresh < SHRT_MIN) ||
               (type == THRESH_TOZERO && ithresh >= SHRT_MAX) )
            {
                int v = type == THRESH_BINARY ? (ithresh >= SHRT_MAX ? 0 : imaxval) :