opencv基礎-高斯平滑濾波

函式原型

cv::GaussianBlur( src, dst, cv::Size(param1, param2), param3, param4, cv::BORDER_REPLICATE );

void cv::GaussianBlur( InputArray _src, OutputArray _dst, Size ksize,
                   double sigma1, double sigma2,
                   int borderType )
{
    CV_INSTRUMENT_REGION()

    int type = _src.type();
    Size size = _src.size();
    _dst.create( size, type );

    if( (borderType & ~BORDER_ISOLATED) != BORDER_CONSTANT &&
        ((borderType & BORDER_ISOLATED) != 0 || !_src.getMat().isSubmatrix()) )
    {
        if( size.height == 1 )
            ksize.height = 1;
        if( size.width == 1 )
            ksize.width = 1;
    }

    if( ksize.width == 1 && ksize.height == 1 )
    {
        _src.copyTo(_dst);
        return;
    }

    bool useOpenCL = (ocl::isOpenCLActivated() && _dst.isUMat() && _src.dims() <= 2 &&
               ((ksize.width == 3 && ksize.height == 3) ||
               (ksize.width == 5 && ksize.height == 5)) &&
               _src.rows() > ksize.height && _src.cols() > ksize.width);
    (void)useOpenCL;

    int sdepth = CV_MAT_DEPTH(type), cn = CV_MAT_CN(type);

    if(sdepth == CV_8U && ((borderType & BORDER_ISOLATED) || !_src.getMat().isSubmatrix()))
    {
        std::vector<ufixedpoint16> fkx, fky;
        createGaussianKernels(fkx, fky, type, ksize, sigma1, sigma2);
        Mat src = _src.getMat();
        Mat dst = _dst.getMat();
        if (src.data == dst.data)
            src = src.clone();
        fixedSmoothInvoker<uint8_t, ufixedpoint16> invoker(src.ptr<uint8_t>(), src.step1(), dst.ptr<uint8_t>(), dst.step1(), dst.cols, dst.rows, dst.channels(), &fkx[0], (int)fkx.size(), &fky[0], (int)fky.size(), borderType & ~BORDER_ISOLATED);
        parallel_for_(Range(0, dst.rows), invoker, std::max(1, std::min(getNumThreads(), getNumberOfCPUs())));
        return;
    }


    Mat kx, ky;
    createGaussianKernels(kx, ky, type, ksize, sigma1, sigma2);

    CV_OCL_RUN(useOpenCL, ocl_GaussianBlur_8UC1(_src, _dst, ksize, CV_MAT_DEPTH(type), kx, ky, borderType));

    CV_OCL_RUN(_dst.isUMat() && _src.dims() <= 2 && (size_t)_src.rows() > kx.total() && (size_t)_src.cols() > kx.total(),
               ocl_sepFilter2D(_src, _dst, sdepth, kx, ky, Point(-1, -1), 0, borderType))

    Mat src = _src.getMat();
    Mat dst = _dst.getMat();

    Point ofs;
    Size wsz(src.cols, src.rows);
    if(!(borderType & BORDER_ISOLATED))
        src.locateROI( wsz, ofs );

    CALL_HAL(gaussianBlur, cv_hal_gaussianBlur, src.ptr(), src.step, dst.ptr(), dst.step, src.cols, src.rows, sdepth, cn,
             ofs.x, ofs.y, wsz.width - src.cols - ofs.x, wsz.height - src.rows - ofs.y, ksize.width, ksize.height,
             sigma1, sigma2, borderType&~BORDER_ISOLATED);

    CV_OVX_RUN(true,
               openvx_gaussianBlur(src, dst, ksize, sigma1, sigma2, borderType))

    CV_IPP_RUN_FAST(ipp_GaussianBlur(src, dst, ksize, sigma1, sigma2, borderType));

    sepFilter2D(src, dst, sdepth, kx, ky, Point(-1, -1), 0, borderType);
}