opencv erode

opencv erode

void cv::erode( InputArray src, OutputArray dst, InputArray kernel,
                Point anchor, int iterations,
                int borderType, const Scalar& borderValue )
{
    CV_INSTRUMENT_REGION()

    morphOp( MORPH_ERODE, src, dst, kernel, anchor, iterations, borderType, borderValue );
}

static void morphOp( int op, InputArray _src, OutputArray _dst,
                     InputArray _kernel,
                     Point anchor, int iterations,
                     int borderType, const Scalar& borderValue )
{
    CV_INSTRUMENT_REGION()

    Mat kernel = _kernel.getMat();
    Size ksize = !kernel.empty() ? kernel.size() : Size(3,3);
    anchor = normalizeAnchor(anchor, ksize);

    CV_OCL_RUN(_dst.isUMat() && _src.dims() <= 2 && _src.channels() <= 4 &&
               borderType == cv::BORDER_CONSTANT && borderValue == morphologyDefaultBorderValue() &&
               (op == MORPH_ERODE || op == MORPH_DILATE) &&
               anchor.x == ksize.width >> 1 && anchor.y == ksize.height >> 1,
               ocl_morphOp(_src, _dst, kernel, anchor, iterations, op, borderType, borderValue) )

    if (iterations == 0 || kernel.rows*kernel.cols == 1)
    {
        _src.copyTo(_dst);
        return;
    }

    if (kernel.empty())
    {
        kernel = getStructuringElement(MORPH_RECT, Size(1+iterations*2,1+iterations*2));
        anchor = Point(iterations, iterations);
        iterations = 1;
    }
    else if( iterations > 1 && countNonZero(kernel) == kernel.rows*kernel.cols )
    {
        anchor = Point(anchor.x*iterations, anchor.y*iterations);
        kernel = getStructuringElement(MORPH_RECT,
                                       Size(ksize.width + (iterations-1)*(ksize.width-1),
                                            ksize.height + (iterations-1)*(ksize.height-1)),
                                       anchor);
        iterations = 1;
    }

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

    Point s_ofs;
    Size s_wsz(src.cols, src.rows);
    Point d_ofs;
    Size d_wsz(dst.cols, dst.rows);
    bool isolated = (borderType&BORDER_ISOLATED)?true:false;
    borderType = (borderType&~BORDER_ISOLATED);

    if(!isolated)
    {
        src.locateROI(s_wsz, s_ofs);
        dst.locateROI(d_wsz, d_ofs);
    }

    hal::morph(op, src.type(), dst.type(),
               src.data, src.step,
               dst.data, dst.step,
               src.cols, src.rows,
               s_wsz.width, s_wsz.height, s_ofs.x, s_ofs.y,
               d_wsz.width, d_wsz.height, d_ofs.x, d_ofs.y,
               kernel.type(), kernel.data, kernel.step, kernel.cols, kernel.rows, anchor.x, anchor.y,
               borderType, borderValue.val, iterations,
               (src.isSubmatrix() && !isolated));
}

代码参考：opencv3_4_1opencv-3.4.1modulesimgprocsrcmorph.cpp

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