cvcontours.cpp

将OpenCV移植到DSP上

    CvSeqWriter  writer_ext;
    CvSeqWriter  writer_int;
    CvSeqWriter  writer;
    CvSeqReader  reader;

    CvSeq* external_contours;
    CvSeq* internal_contours;
    CvSeq* prev = 0;

    if( !storage )
        CV_ERROR( CV_StsNullPtr, "NULL storage pointer" );

    if( !result )
        CV_ERROR( CV_StsNullPtr, "NULL double CvSeq pointer" );

    if( contourHeaderSize < (int)sizeof(CvContour))
        CV_ERROR( CV_StsBadSize, "Contour header size must be >= sizeof(CvContour)" );

    CV_CALL( storage00 = cvCreateChildMemStorage(storage));
    CV_CALL( storage01 = cvCreateChildMemStorage(storage));

    {
        CvMat stub, *mat;

        CV_CALL( mat = cvGetMat( src, &stub ));
        if( !CV_IS_MASK_ARR(mat))
            CV_ERROR( CV_StsBadArg, "Input array must be 8uC1 or 8sC1" );
        src_data = mat->data.ptr;
        img_step = mat->step;
        img_size = cvGetMatSize( mat );
    }

    // Create temporary sequences
    runs = cvCreateSeq(0, sizeof(CvSeq), sizeof(CvLinkedRunPoint), storage00 );
    cvStartAppendToSeq( runs, &writer );

    cvStartWriteSeq( 0, sizeof(CvSeq), sizeof(CvLinkedRunPoint*), storage01, &writer_ext );
    cvStartWriteSeq( 0, sizeof(CvSeq), sizeof(CvLinkedRunPoint*), storage01, &writer_int );

    tmp_prev = &(tmp);
    tmp_prev->next = 0;
    tmp_prev->link = 0;
    
    // First line. None of runs is binded
    tmp.pt.y = 0;
    i = 0;
    CV_WRITE_SEQ_ELEM( tmp, writer );
    upper_line = (CvLinkedRunPoint*)CV_GET_WRITTEN_ELEM( writer );
    
    tmp_prev = upper_line;
    for( j = 0; j < img_size.width; )
    {
        for( ; j < img_size.width && !ICV_IS_COMPONENT_POINT(src_data[j]); j++ )
            ;
        if( j == img_size.width )
            break;

        tmp.pt.x = j;
        CV_WRITE_SEQ_ELEM( tmp, writer );
        tmp_prev->next = (CvLinkedRunPoint*)CV_GET_WRITTEN_ELEM( writer );
        tmp_prev = tmp_prev->next;

        for( ; j < img_size.width && ICV_IS_COMPONENT_POINT(src_data[j]); j++ )
            ;

        tmp.pt.x = j-1;
        CV_WRITE_SEQ_ELEM( tmp, writer );
        tmp_prev->next = (CvLinkedRunPoint*)CV_GET_WRITTEN_ELEM( writer );
        tmp_prev->link = tmp_prev->next;
        // First point of contour
        CV_WRITE_SEQ_ELEM( tmp_prev, writer_ext );
        tmp_prev = tmp_prev->next;
    }
    cvFlushSeqWriter( &writer );
    upper_line = upper_line->next;
    upper_total = runs->total - 1;
    last_elem = tmp_prev;
    tmp_prev->next = 0;
    
    for( i = 1; i < img_size.height; i++ )
    {
//------// Find runs in next line
        src_data += img_step;
        tmp.pt.y = i;
        all_total = runs->total;
        for( j = 0; j < img_size.width; )
        {
            for( ; j < img_size.width && !ICV_IS_COMPONENT_POINT(src_data[j]); j++ )
                ;
            if( j == img_size.width ) break;

            tmp.pt.x = j;
            CV_WRITE_SEQ_ELEM( tmp, writer );
            tmp_prev->next = (CvLinkedRunPoint*)CV_GET_WRITTEN_ELEM( writer );
            tmp_prev = tmp_prev->next;

            for( ; j < img_size.width && ICV_IS_COMPONENT_POINT(src_data[j]); j++ )
                ;

            tmp.pt.x = j-1;
            CV_WRITE_SEQ_ELEM( tmp, writer );
            tmp_prev = tmp_prev->next = (CvLinkedRunPoint*)CV_GET_WRITTEN_ELEM( writer );
        }//j
        cvFlushSeqWriter( &writer );
        lower_line = last_elem->next;
        lower_total = runs->total - all_total;
        last_elem = tmp_prev;
        tmp_prev->next = 0;
//------//
//------// Find links between runs of lower_line and upper_line
        upper_run = upper_line;
        lower_run = lower_line;
        connect_flag = ICV_SINGLE;

        for( k = 0, n = 0; k < upper_total/2 && n < lower_total/2; )
        {
            switch( connect_flag )
            {
            case ICV_SINGLE:
                if( upper_run->next->pt.x < lower_run->next->pt.x )
                {
                    if( upper_run->next->pt.x >= lower_run->pt.x  -1 )
                    {
                        lower_run->link = upper_run;
                        connect_flag = ICV_CONNECTING_ABOVE;
                        prev_point = upper_run->next;
                    }
                    else
                        upper_run->next->link = upper_run;
                    k++;
                    upper_run = upper_run->next->next;
                }
                else
                {
                    if( upper_run->pt.x <= lower_run->next->pt.x  +1 )
                    {
                        lower_run->link = upper_run;
                        connect_flag = ICV_CONNECTING_BELOW;
                        prev_point = lower_run->next;
                    }
                    else
                    {
                        lower_run->link = lower_run->next;
                        // First point of contour
                        CV_WRITE_SEQ_ELEM( lower_run, writer_ext );
                    }
                    n++;
                    lower_run = lower_run->next->next;
                }
                break;
            case ICV_CONNECTING_ABOVE:
                if( upper_run->pt.x > lower_run->next->pt.x +1 )
                {
                    prev_point->link = lower_run->next;
                    connect_flag = ICV_SINGLE;
                    n++;
                    lower_run = lower_run->next->next;
                }
                else
                {
                    prev_point->link = upper_run;
                    if( upper_run->next->pt.x < lower_run->next->pt.x )
                    {
                        k++;
                        prev_point = upper_run->next;
                        upper_run = upper_run->next->next;
                    }
                    else
                    {
                        connect_flag = ICV_CONNECTING_BELOW;
                        prev_point = lower_run->next;
                        n++;
                        lower_run = lower_run->next->next;
                    }
                }
                break;
            case ICV_CONNECTING_BELOW:
                if( lower_run->pt.x > upper_run->next->pt.x +1 )
                {
                    upper_run->next->link = prev_point;
                    connect_flag = ICV_SINGLE;
                    k++;
                    upper_run = upper_run->next->next;
                }
                else
                {
                    // First point of contour
                    CV_WRITE_SEQ_ELEM( lower_run, writer_int );

                    lower_run->link = prev_point;
                    if( lower_run->next->pt.x < upper_run->next->pt.x )
                    {
                        n++;
                        prev_point = lower_run->next;
                        lower_run = lower_run->next->next;
                    }
                    else
                    {
                        connect_flag = ICV_CONNECTING_ABOVE;
                        k++;
                        prev_point = upper_run->next;
                        upper_run = upper_run->next->next;
                    }
                }
                break;          
            }
        }// k, n

        for( ; n < lower_total/2; n++ )
        {
            if( connect_flag != ICV_SINGLE )
            {
                prev_point->link = lower_run->next;
                connect_flag = ICV_SINGLE;
                lower_run = lower_run->next->next;
                continue;
            }
            lower_run->link = lower_run->next;

            //First point of contour
            CV_WRITE_SEQ_ELEM( lower_run, writer_ext );

            lower_run = lower_run->next->next;
        }

        for( ; k < upper_total/2; k++ )
        {
            if( connect_flag != ICV_SINGLE )
            {
                upper_run->next->link = prev_point;
                connect_flag = ICV_SINGLE;
                upper_run = upper_run->next->next;
                continue;
            }
            upper_run->next->link = upper_run;
            upper_run = upper_run->next->next;
        }
        upper_line = lower_line;
        upper_total = lower_total;
    }//i

    upper_run = upper_line;

    //the last line of image
    for( k = 0; k < upper_total/2; k++ )
    {
        upper_run->next->link = upper_run;
        upper_run = upper_run->next->next;
    }

//------//
//------//Find end read contours
    external_contours = cvEndWriteSeq( &writer_ext );
    internal_contours = cvEndWriteSeq( &writer_int );

    for( k = 0; k < 2; k++ )
    {
        CvSeq* contours = k == 0 ? external_contours : internal_contours;

        cvStartReadSeq( contours, &reader );

        for( j = 0; j < contours->total; j++, count++ )
        {
            CvLinkedRunPoint* p_temp;
            CvLinkedRunPoint* p00;
            CvLinkedRunPoint* p01;
            CvSeq* contour;

            CV_READ_SEQ_ELEM( p00, reader );
            p01 = p00;

            if( !p00->link )
                continue;

            cvStartWriteSeq( CV_SEQ_ELTYPE_POINT | CV_SEQ_POLYLINE | CV_SEQ_FLAG_CLOSED,
                             contourHeaderSize, sizeof(CvPoint), storage, &writer );
            do
            {
                CV_WRITE_SEQ_ELEM( p00->pt, writer );
                p_temp = p00;
                p00 = p00->link;
                p_temp->link = 0;
            }
            while( p00 != p01 );

            contour = cvEndWriteSeq( &writer );
            cvBoundingRect( contour, 1 );

            if( k != 0 )
                contour->flags |= CV_SEQ_FLAG_HOLE;

            if( !first )
                prev = first = contour;
            else
            {
                contour->h_prev = prev;
                prev = prev->h_next = contour;
            }
        }
    }

    __END__;

    if( !first )
        count = -1;

    if( result )
        *result = first;

    cvReleaseMemStorage(&storage00);
    cvReleaseMemStorage(&storage01);

    return count;
}



/*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.
//      size - width and height of the image in pixels
//      storage - pointer to storage where will the output contours be placed.
//      header_size - header size of resulting contours
//      mode - mode of contour retrieval.
//      method - method of approximation that is applied to contours
//      first_contour - pointer to first contour pointer
//    Returns:
//      CV_OK or error code
//    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;
    
    CV_FUNCNAME( "cvFindContours" );

    __BEGIN__;

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

    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" );

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

        do
        {
            count++;
            contour = cvFindNextContour( scanner );
        }
        while( contour != 0 );

        *firstContour = cvEndFindContours( &scanner );    
    }

    __END__;

    return count;
}


/* End of file. */