Function cvFindContours

deps/opencv/modules/imgproc/src/contours.cpp:1659–1706

F/////////////////////////////////////////////////////////////////////////////////////// // Name: cvFindContours // Purpose: // Finds all the contours on the bi-level image. // Context: // Parameters: // img - source image. // Non-zero pixels are considered as 1-pixels // and zero pixels as 0-pixels. // step - full width of source image in bytes.

//    Notes:
//F*/
CV_IMPL int
cvFindContours( void*  img,  CvMemStorage*  storage,
                CvSeq**  firstContour, int  cntHeaderSize,
                int  mode,
                int  method, CvPoint offset )
{
    CvContourScanner scanner = 0;
    CvSeq *contour = 0;
    int count = -1;

    if( !firstContour )
        CV_Error( CV_StsNullPtr, "NULL double CvSeq pointer" );

    *firstContour = 0;

    if( method == CV_LINK_RUNS )
    {
        if( offset.x != 0 || offset.y != 0 )
            CV_Error( CV_StsOutOfRange,
            "Nonzero offset is not supported in CV_LINK_RUNS yet" );

        count = icvFindContoursInInterval( img, storage, firstContour, cntHeaderSize );
    }
    else
    {
        try
        {
            scanner = cvStartFindContours( img, storage, cntHeaderSize, mode, method, offset );

            do
            {
                count++;
                contour = cvFindNextContour( scanner );
            }
            while( contour != 0 );
        }
        catch(...)
        {
            if( scanner )
                cvEndFindContours(&scanner);
            throw;
        }

        *firstContour = cvEndFindContours( &scanner );
    }

    return count;
}

void cv::findContours( InputOutputArray _image, OutputArrayOfArrays _contours,
                   OutputArray _hierarchy, int mode, int method, Point offset )