opencv-MIRROR/modules/imgproc/src/canny.cpp

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#include "precomp.hpp"
#include "opencl_kernels_imgproc.hpp"
#include "canny.hpp"
#include <deque>

namespace cv
{

#ifdef HAVE_OPENCL

template <bool useCustomDeriv>
static bool ocl_Canny(InputArray _src, const UMat& dx_, const UMat& dy_, OutputArray _dst, float low_thresh, float high_thresh,
                      int aperture_size, bool L2gradient, int cn, const Size & size)
{
    CV_INSTRUMENT_REGION_OPENCL();

    UMat map;

    const ocl::Device &dev = ocl::Device::getDefault();
    int max_wg_size = (int)dev.maxWorkGroupSize();

    int lSizeX = 32;
    int lSizeY = max_wg_size / 32;

    if (lSizeY == 0)
    {
        lSizeX = 16;
        lSizeY = max_wg_size / 16;
    }
    if (lSizeY == 0)
    {
        lSizeY = 1;
    }

    if (aperture_size == 7)
    {
        low_thresh = low_thresh / 16.0f;
        high_thresh = high_thresh / 16.0f;
    }

    if (L2gradient)
    {
        low_thresh = std::min(32767.0f, low_thresh);
        high_thresh = std::min(32767.0f, high_thresh);

        if (low_thresh > 0)
            low_thresh *= low_thresh;
        if (high_thresh > 0)
            high_thresh *= high_thresh;
    }
    int low = cvFloor(low_thresh), high = cvFloor(high_thresh);

    if (!useCustomDeriv &&
        aperture_size == 3 && !_src.isSubmatrix())
    {
        /*
            stage1_with_sobel:
                Sobel operator
                Calc magnitudes
                Non maxima suppression
                Double thresholding
        */
        char cvt[50];
        ocl::Kernel with_sobel("stage1_with_sobel", ocl::imgproc::canny_oclsrc,
                               format("-D WITH_SOBEL -D cn=%d -D TYPE=%s -D convert_floatN=%s -D floatN=%s -D GRP_SIZEX=%d -D GRP_SIZEY=%d%s",
                                      cn, ocl::memopTypeToStr(_src.depth()),
                                      ocl::convertTypeStr(_src.depth(), CV_32F, cn, cvt, sizeof(cvt)),
                                      ocl::typeToStr(CV_MAKE_TYPE(CV_32F, cn)),
                                      lSizeX, lSizeY,
                                      L2gradient ? " -D L2GRAD" : ""));
        if (with_sobel.empty())
            return false;

        UMat src = _src.getUMat();
        map.create(size, CV_32S);
        with_sobel.args(ocl::KernelArg::ReadOnly(src),
                        ocl::KernelArg::WriteOnlyNoSize(map),
                        (float) low, (float) high);

        size_t globalsize[2] = { (size_t)size.width, (size_t)size.height },
                localsize[2] = { (size_t)lSizeX, (size_t)lSizeY };

        if (!with_sobel.run(2, globalsize, localsize, false))
            return false;
    }
    else
    {
        /*
            stage1_without_sobel:
                Calc magnitudes
                Non maxima suppression
                Double thresholding
        */
        double scale = 1.0;
        if (aperture_size == 7)
        {
            scale = 1 / 16.0;
        }

        UMat dx, dy;
        if (!useCustomDeriv)
        {
            Sobel(_src, dx, CV_16S, 1, 0, aperture_size, scale, 0, BORDER_REPLICATE);
            Sobel(_src, dy, CV_16S, 0, 1, aperture_size, scale, 0, BORDER_REPLICATE);
        }
        else
        {
            dx = dx_;
            dy = dy_;
        }

        ocl::Kernel without_sobel("stage1_without_sobel", ocl::imgproc::canny_oclsrc,
                                    format("-D WITHOUT_SOBEL -D cn=%d -D GRP_SIZEX=%d -D GRP_SIZEY=%d%s",
                                           cn, lSizeX, lSizeY, L2gradient ? " -D L2GRAD" : ""));
        if (without_sobel.empty())
            return false;

        map.create(size, CV_32S);
        without_sobel.args(ocl::KernelArg::ReadOnlyNoSize(dx), ocl::KernelArg::ReadOnlyNoSize(dy),
                           ocl::KernelArg::WriteOnly(map),
                           low, high);

        size_t globalsize[2] = { (size_t)size.width, (size_t)size.height },
                localsize[2] = { (size_t)lSizeX, (size_t)lSizeY };

        if (!without_sobel.run(2, globalsize, localsize, false))
            return false;
    }

    int PIX_PER_WI = 8;
    /*
        stage2:
            hysteresis (add weak edges if they are connected with strong edges)
    */

    int sizey = lSizeY / PIX_PER_WI;
    if (sizey == 0)
        sizey = 1;

    size_t globalsize[2] = { (size_t)size.width, ((size_t)size.height + PIX_PER_WI - 1) / PIX_PER_WI }, localsize[2] = { (size_t)lSizeX, (size_t)sizey };

    ocl::Kernel edgesHysteresis("stage2_hysteresis", ocl::imgproc::canny_oclsrc,
                                format("-D STAGE2 -D PIX_PER_WI=%d -D LOCAL_X=%d -D LOCAL_Y=%d",
                                PIX_PER_WI, lSizeX, sizey));

    if (edgesHysteresis.empty())
        return false;

    edgesHysteresis.args(ocl::KernelArg::ReadWrite(map));
    if (!edgesHysteresis.run(2, globalsize, localsize, false))
        return false;

    // get edges

    ocl::Kernel getEdgesKernel("getEdges", ocl::imgproc::canny_oclsrc,
                                format("-D GET_EDGES -D PIX_PER_WI=%d", PIX_PER_WI));
    if (getEdgesKernel.empty())
        return false;

    _dst.create(size, CV_8UC1);
    UMat dst = _dst.getUMat();

    getEdgesKernel.args(ocl::KernelArg::ReadOnly(map), ocl::KernelArg::WriteOnlyNoSize(dst));

    return getEdgesKernel.run(2, globalsize, NULL, false);
}

#endif

#define CANNY_PUSH(map, stack) *map = 2, stack.push_back(map)

#define CANNY_CHECK(m, high, map, stack) \
    if (m > high) \
        CANNY_PUSH(map, stack); \
    else \
        *map = 0

class parallelCanny : public ParallelLoopBody
{
public:
    parallelCanny(const Mat &_src, Mat &_map, std::deque<uchar*> &borderPeaksParallel,
                  int _low, int _high, int _aperture_size, bool _L2gradient) :
        src(_src), src2(_src), map(_map), _borderPeaksParallel(borderPeaksParallel),
        low(_low), high(_high), aperture_size(_aperture_size), L2gradient(_L2gradient),
        simdWidth(canny_simd_width())
    {
        _map.create(src.rows + 2, (int)alignSize((size_t)(src.cols + simdWidth + 1), simdWidth), CV_8UC1);
        map = _map;
        map.row(0).setTo(1);
        map.row(src.rows + 1).setTo(1);
        mapstep = map.cols;
        needGradient = true;
        cn = src.channels();
    }

    parallelCanny(const Mat &_dx, const Mat &_dy, Mat &_map, std::deque<uchar*> &borderPeaksParallel,
                  int _low, int _high, bool _L2gradient) :
        src(_dx), src2(_dy), map(_map), _borderPeaksParallel(borderPeaksParallel),
        low(_low), high(_high), aperture_size(0), L2gradient(_L2gradient),
        simdWidth(canny_simd_width())
    {
        _map.create(src.rows + 2, (int)alignSize((size_t)(src.cols + simdWidth + 1), simdWidth), CV_8UC1);
        map = _map;
        map.row(0).setTo(1);
        map.row(src.rows + 1).setTo(1);
        mapstep = map.cols;
        needGradient = false;
        cn = src.channels();
    }

    ~parallelCanny() {}

    parallelCanny& operator=(const parallelCanny&) { return *this; }

    void operator()(const Range &boundaries) const CV_OVERRIDE
    {
        CV_TRACE_FUNCTION();

        CV_DbgAssert(cn > 0);

        Mat dx, dy;
        AutoBuffer<short> dxMax(0), dyMax(0);
        std::deque<uchar*> stack, borderPeaksLocal;
        const int rowStart = max(0, boundaries.start - 1), rowEnd = min(src.rows, boundaries.end + 1);
        int *_mag_p, *_mag_a, *_mag_n;
        short *_dx, *_dy, *_dx_a = NULL, *_dy_a = NULL, *_dx_n = NULL, *_dy_n = NULL;
        uchar *_pmap;
        double scale = 1.0;

        CV_TRACE_REGION("gradient")
        if(needGradient)
        {
            scale = (aperture_size == 7) ? (1 / 16.0) : 1.0;
            spatialGradient(src.rowRange(rowStart, rowEnd), dx, dy, aperture_size, BORDER_REPLICATE, CV_16S, scale);
        }
        else
        {
            dx = src.rowRange(rowStart, rowEnd);
            dy = src2.rowRange(rowStart, rowEnd);
        }

        CV_TRACE_REGION_NEXT("magnitude");
        if(cn > 1)
        {
            dxMax.allocate(2 * dx.cols);
            dyMax.allocate(2 * dy.cols);
            _dx_a = dxMax.data();
            _dx_n = _dx_a + dx.cols;
            _dy_a = dyMax.data();
            _dy_n = _dy_a + dy.cols;
        }

        // _mag_p: previous row, _mag_a: actual row, _mag_n: next row
        AutoBuffer<int> buffer(3 * (mapstep * cn + simdWidth));
        _mag_p = alignPtr(buffer.data() + 1, simdWidth);
        _mag_a = alignPtr(_mag_p + mapstep * cn, simdWidth);
        _mag_n = alignPtr(_mag_a + mapstep * cn, simdWidth);

        // For the first time when just 2 rows are filled and for left and right borders
        if(rowStart == boundaries.start)
            memset(_mag_n - 1, 0, mapstep * sizeof(int));
        else
            _mag_n[src.cols] = _mag_n[-1] = 0;

        _mag_a[src.cols] = _mag_a[-1] = _mag_p[src.cols] = _mag_p[-1] = 0;

        // calculate magnitude and angle of gradient, perform non-maxima suppression.
        // fill the map with one of the following values:
        //   0 - the pixel might belong to an edge
        //   1 - the pixel can not belong to an edge
        //   2 - the pixel does belong to an edge
        for (int i = rowStart; i <= boundaries.end; ++i)
        {
            // Scroll the ring buffer
            std::swap(_mag_n, _mag_a);
            std::swap(_mag_n, _mag_p);

            if(i < rowEnd)
            {
                // Next row calculation
                _dx = dx.ptr<short>(i - rowStart);
                _dy = dy.ptr<short>(i - rowStart);

                canny_calc_magnitude(_dx, _dy, _mag_n, src.cols * cn, L2gradient);

                if(cn > 1)
                {
                    std::swap(_dx_n, _dx_a);
                    std::swap(_dy_n, _dy_a);

                    for(int j = 0, jn = 0; j < src.cols; ++j, jn += cn)
                    {
                        int maxIdx = jn;
                        for(int k = 1; k < cn; ++k)
                            if(_mag_n[jn + k] > _mag_n[maxIdx]) maxIdx = jn + k;

                        _mag_n[j] = _mag_n[maxIdx];
                        _dx_n[j] = _dx[maxIdx];
                        _dy_n[j] = _dy[maxIdx];
                    }

                    _mag_n[src.cols] = 0;
                }

                // at the very beginning we do not have a complete ring
                // buffer of 3 magnitude rows for non-maxima suppression
                if (i <= boundaries.start)
                    continue;
            }
            else
            {
                memset(_mag_n - 1, 0, mapstep * sizeof(int));

                if(cn > 1)
                {
                    std::swap(_dx_n, _dx_a);
                    std::swap(_dy_n, _dy_a);
                }
            }

            // From here actual src row is (i - 1)
            // Set left and right border to 1
            _pmap = map.ptr<uchar>(i) + simdWidth;

            _pmap[src.cols] =_pmap[-1] = 1;

            if(cn == 1)
            {
                _dx = dx.ptr<short>(i - rowStart - 1);
                _dy = dy.ptr<short>(i - rowStart - 1);
            }
            else
            {
                _dx = _dx_a;
                _dy = _dy_a;
            }

            canny_nms_row(_mag_a, _mag_p, _mag_n, _dx, _dy, _pmap, src.cols, low, high, stack);
        }

        // Not for first row of first slice or last row of last slice
        uchar *pmapLower = (rowStart == 0) ? map.data : (map.data + (boundaries.start + 2) * mapstep);
        uint pmapDiff = (uint)(((rowEnd == src.rows) ? map.datalimit : (map.data + boundaries.end * mapstep)) - pmapLower);

        // now track the edges (hysteresis thresholding)
        CV_TRACE_REGION_NEXT("hysteresis");
        while (!stack.empty())
        {
            uchar *m = stack.back();
            stack.pop_back();

            // Stops thresholding from expanding to other slices by sending pixels in the borders of each
            // slice in a queue to be serially processed later.
            if((unsigned)(m - pmapLower) < pmapDiff)
            {
                if (!m[-mapstep-1]) CANNY_PUSH((m-mapstep-1), stack);
                if (!m[-mapstep])   CANNY_PUSH((m-mapstep), stack);
                if (!m[-mapstep+1]) CANNY_PUSH((m-mapstep+1), stack);
                if (!m[-1])         CANNY_PUSH((m-1), stack);
                if (!m[1])          CANNY_PUSH((m+1), stack);
                if (!m[mapstep-1])  CANNY_PUSH((m+mapstep-1), stack);
                if (!m[mapstep])    CANNY_PUSH((m+mapstep), stack);
                if (!m[mapstep+1])  CANNY_PUSH((m+mapstep+1), stack);
            }
            else
            {
                borderPeaksLocal.push_back(m);
                ptrdiff_t mapstep2 = m < pmapLower ? mapstep : -mapstep;

                if (!m[-1])         CANNY_PUSH((m-1), stack);
                if (!m[1])          CANNY_PUSH((m+1), stack);
                if (!m[mapstep2-1]) CANNY_PUSH((m+mapstep2-1), stack);
                if (!m[mapstep2])   CANNY_PUSH((m+mapstep2), stack);
                if (!m[mapstep2+1]) CANNY_PUSH((m+mapstep2+1), stack);
            }
        }

        if(!borderPeaksLocal.empty())
        {
            AutoLock lock(mutex);
            _borderPeaksParallel.insert(_borderPeaksParallel.end(), borderPeaksLocal.begin(), borderPeaksLocal.end());
        }
    }

private:
    const Mat &src, &src2;
    Mat &map;
    std::deque<uchar*> &_borderPeaksParallel;
    int low, high, aperture_size;
    bool L2gradient, needGradient;
    ptrdiff_t mapstep;
    int cn;
    int simdWidth;
    mutable Mutex mutex;
};

class finalPass : public ParallelLoopBody
{

public:
    finalPass(const Mat &_map, Mat &_dst) :
        map(_map), dst(_dst)
    {
        dst = _dst;
    }

    ~finalPass() {}

    void operator()(const Range &boundaries) const CV_OVERRIDE
    {
        // the final pass, form the final image. The map's left padding matches the
        // width used by parallelCanny when it was allocated (same dispatched value).
        const int simdWidth = canny_simd_width();
        for (int i = boundaries.start; i < boundaries.end; i++)
        {
            uchar *pdst = dst.ptr<uchar>(i);
            const uchar *pmap = map.ptr<uchar>(i + 1) + simdWidth;
            canny_finalize_row(pmap, pdst, dst.cols);
        }
    }

private:
    const Mat &map;
    Mat &dst;

    finalPass(const finalPass&); // = delete
    finalPass& operator=(const finalPass&); // = delete
};

void Canny( InputArray _src, OutputArray _dst,
                double low_thresh, double high_thresh,
                int aperture_size, bool L2gradient )
{
    CV_INSTRUMENT_REGION();

    CV_Assert( _src.depth() == CV_8U );

    const Size size = _src.size();

    // we don't support inplace parameters in case with RGB/BGR src
    CV_Assert((_dst.getObj() != _src.getObj() || _src.type() == CV_8UC1) && "Inplace parameters are not supported");

    _dst.create(size, CV_8U);

    // backward compatibility
    const int CV_CANNY_L2_GRADIENT = (1 << 31);
    if (!L2gradient && (aperture_size & CV_CANNY_L2_GRADIENT) == CV_CANNY_L2_GRADIENT)
    {
        aperture_size &= ~CV_CANNY_L2_GRADIENT;
        L2gradient = true;
    }

    if ((aperture_size & 1) == 0 || (aperture_size != -1 && (aperture_size < 3 || aperture_size > 7)))
        CV_Error(cv::Error::StsBadFlag, "Aperture size should be odd between 3 and 7");

    if (aperture_size == 7)
    {
        low_thresh = low_thresh / 16.0;
        high_thresh = high_thresh / 16.0;
    }

    if (low_thresh > high_thresh)
        std::swap(low_thresh, high_thresh);

    CV_OCL_RUN(_dst.isUMat() && (_src.channels() == 1 || _src.channels() == 3),
               ocl_Canny<false>(_src, UMat(), UMat(), _dst, (float)low_thresh, (float)high_thresh, aperture_size, L2gradient, _src.channels(), size))

    Mat src0 = _src.getMat(), dst = _dst.getMat();
    Mat src(src0.size(), src0.type(), src0.data, src0.step);

    CALL_HAL(canny, cv_hal_canny, src.data, src.step, dst.data, dst.step, src.cols, src.rows, src.channels(),
             low_thresh, high_thresh, aperture_size, L2gradient);

    if (L2gradient)
    {
        low_thresh = std::min(32767.0, low_thresh);
        high_thresh = std::min(32767.0, high_thresh);

        if (low_thresh > 0) low_thresh *= low_thresh;
        if (high_thresh > 0) high_thresh *= high_thresh;
    }
    int low = cvFloor(low_thresh);
    int high = cvFloor(high_thresh);

    // If Scharr filter: aperture size is 3, ksize2 is 1
    int ksize2 = aperture_size < 0 ? 1 : aperture_size / 2;
    // Minimum number of threads should be 1, maximum should not exceed number of CPU's, because of overhead
    int numOfThreads = std::max(1, std::min(getNumThreads(), getNumberOfCPUs()));
    // Make a fallback for pictures with too few rows.
    int grainSize = src.rows / numOfThreads;
    int minGrainSize = 2 * (ksize2 + 1);
    if (grainSize < minGrainSize)
        numOfThreads = std::max(1, src.rows / minGrainSize);

    Mat map;
    std::deque<uchar*> stack;

    parallel_for_(Range(0, src.rows), parallelCanny(src, map, stack, low, high, aperture_size, L2gradient), numOfThreads);

    CV_TRACE_REGION("global_hysteresis");
    // now track the edges (hysteresis thresholding)
    ptrdiff_t mapstep = map.cols;

    while (!stack.empty())
    {
        uchar* m = stack.back();
        stack.pop_back();

        if (!m[-mapstep-1]) CANNY_PUSH((m-mapstep-1), stack);
        if (!m[-mapstep])   CANNY_PUSH((m-mapstep), stack);
        if (!m[-mapstep+1]) CANNY_PUSH((m-mapstep+1), stack);
        if (!m[-1])         CANNY_PUSH((m-1), stack);
        if (!m[1])          CANNY_PUSH((m+1), stack);
        if (!m[mapstep-1])  CANNY_PUSH((m+mapstep-1), stack);
        if (!m[mapstep])    CANNY_PUSH((m+mapstep), stack);
        if (!m[mapstep+1])  CANNY_PUSH((m+mapstep+1), stack);
    }

    CV_TRACE_REGION_NEXT("finalPass");
    parallel_for_(Range(0, src.rows), finalPass(map, dst), src.total()/(double)(1<<16));
}

void Canny( InputArray _dx, InputArray _dy, OutputArray _dst,
                double low_thresh, double high_thresh,
                bool L2gradient )
{
    CV_INSTRUMENT_REGION();

    CV_Assert(_dx.dims() == 2);
    CV_Assert(_dx.type() == CV_16SC1 || _dx.type() == CV_16SC3);
    CV_Assert(_dy.type() == _dx.type());
    CV_Assert(_dx.sameSize(_dy));

    if (low_thresh > high_thresh)
        std::swap(low_thresh, high_thresh);

    const Size size = _dx.size();

    CV_OCL_RUN(_dst.isUMat(),
               ocl_Canny<true>(UMat(), _dx.getUMat(), _dy.getUMat(), _dst, (float)low_thresh, (float)high_thresh, 0, L2gradient, _dx.channels(), size))

    _dst.create(size, CV_8U);
    Mat dst = _dst.getMat();

    Mat dx = _dx.getMat();
    Mat dy = _dy.getMat();

    CALL_HAL(canny_deriv, cv_hal_canny_deriv, dx.ptr<short>(), dx.step, dy.ptr<short>(), dy.step,
             dst.data, dst.step, dx.cols, dx.rows, dx.channels(), low_thresh, high_thresh, L2gradient);

    if (L2gradient)
    {
        low_thresh = std::min(32767.0, low_thresh);
        high_thresh = std::min(32767.0, high_thresh);

        if (low_thresh > 0) low_thresh *= low_thresh;
        if (high_thresh > 0) high_thresh *= high_thresh;
    }

    int low = cvFloor(low_thresh);
    int high = cvFloor(high_thresh);

    std::deque<uchar*> stack;
    Mat map;

    // Minimum number of threads should be 1, maximum should not exceed number of CPU's, because of overhead
    int numOfThreads = std::max(1, std::min(getNumThreads(), getNumberOfCPUs()));
    if (dx.rows / numOfThreads < 3)
        numOfThreads = std::max(1, dx.rows / 3);

    parallel_for_(Range(0, dx.rows), parallelCanny(dx, dy, map, stack, low, high, L2gradient), numOfThreads);

    CV_TRACE_REGION("global_hysteresis")
    // now track the edges (hysteresis thresholding)
    ptrdiff_t mapstep = map.cols;

    while (!stack.empty())
    {
        uchar* m = stack.back();
        stack.pop_back();

        if (!m[-mapstep-1]) CANNY_PUSH((m-mapstep-1), stack);
        if (!m[-mapstep])   CANNY_PUSH((m-mapstep), stack);
        if (!m[-mapstep+1]) CANNY_PUSH((m-mapstep+1), stack);
        if (!m[-1])         CANNY_PUSH((m-1), stack);
        if (!m[1])          CANNY_PUSH((m+1), stack);
        if (!m[mapstep-1])  CANNY_PUSH((m+mapstep-1), stack);
        if (!m[mapstep])    CANNY_PUSH((m+mapstep), stack);
        if (!m[mapstep+1])  CANNY_PUSH((m+mapstep+1), stack);
    }

    CV_TRACE_REGION_NEXT("finalPass");
    parallel_for_(Range(0, dx.rows), finalPass(map, dst), dx.total()/(double)(1<<16));
}

} // namespace cv

void cvCanny( const CvArr* image, CvArr* edges, double threshold1,
              double threshold2, int aperture_size )
{
    cv::Mat src = cv::cvarrToMat(image), dst = cv::cvarrToMat(edges);
    CV_Assert( src.size == dst.size && src.depth() == CV_8U && dst.type() == CV_8U );

    cv::Canny(src, dst, threshold1, threshold2, aperture_size & 255,
              (aperture_size & CV_CANNY_L2_GRADIENT) != 0);
}

/* End of file. */