opencv/modules/gpu/src/hough_lines.cpp

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#include "precomp.hpp"

using namespace std;
using namespace cv;
using namespace cv::gpu;

#if !defined (HAVE_CUDA) || defined (CUDA_DISABLER)

void cv::gpu::HoughLines(const GpuMat&, GpuMat&, float, float, int, bool, int) { throw_nogpu(); }
void cv::gpu::HoughLines(const GpuMat&, GpuMat&, HoughLinesBuf&, float, float, int, bool, int) { throw_nogpu(); }
void cv::gpu::HoughLinesDownload(const GpuMat&, OutputArray, OutputArray) { throw_nogpu(); }

#else /* !defined (HAVE_CUDA) */

namespace cv { namespace gpu { namespace device
{
    namespace hough
    {
        int buildPointList_gpu(PtrStepSzb src, unsigned int* list);
    }
}}}

namespace cv { namespace gpu { namespace device
{
    namespace hough
    {
        void linesAccum_gpu(const unsigned int* list, int count, PtrStepSzi accum, float rho, float theta, size_t sharedMemPerBlock, bool has20);
        int linesGetResult_gpu(PtrStepSzi accum, float2* out, int* votes, int maxSize, float rho, float theta, int threshold, bool doSort);
    }
}}}

void cv::gpu::HoughLines(const GpuMat& src, GpuMat& lines, float rho, float theta, int threshold, bool doSort, int maxLines)
{
    HoughLinesBuf buf;
    HoughLines(src, lines, buf, rho, theta, threshold, doSort, maxLines);
}

void cv::gpu::HoughLines(const GpuMat& src, GpuMat& lines, HoughLinesBuf& buf, float rho, float theta, int threshold, bool doSort, int maxLines)
{
    using namespace cv::gpu::device::hough;

    CV_Assert(src.type() == CV_8UC1);
    CV_Assert(src.cols < std::numeric_limits<unsigned short>::max());
    CV_Assert(src.rows < std::numeric_limits<unsigned short>::max());

    ensureSizeIsEnough(1, src.size().area(), CV_32SC1, buf.list);
    unsigned int* srcPoints = buf.list.ptr<unsigned int>();

    const int pointsCount = buildPointList_gpu(src, srcPoints);
    if (pointsCount == 0)
    {
        lines.release();
        return;
    }

    const int numangle = cvRound(CV_PI / theta);
    const int numrho = cvRound(((src.cols + src.rows) * 2 + 1) / rho);
    CV_Assert(numangle > 0 && numrho > 0);

    ensureSizeIsEnough(numangle + 2, numrho + 2, CV_32SC1, buf.accum);
    buf.accum.setTo(Scalar::all(0));

    DeviceInfo devInfo;
    linesAccum_gpu(srcPoints, pointsCount, buf.accum, rho, theta, devInfo.sharedMemPerBlock(), devInfo.supports(FEATURE_SET_COMPUTE_20));

    ensureSizeIsEnough(2, maxLines, CV_32FC2, lines);

    int linesCount = linesGetResult_gpu(buf.accum, lines.ptr<float2>(0), lines.ptr<int>(1), maxLines, rho, theta, threshold, doSort);
    if (linesCount > 0)
        lines.cols = linesCount;
    else
        lines.release();
}

void cv::gpu::HoughLinesDownload(const GpuMat& d_lines, OutputArray h_lines_, OutputArray h_votes_)
{
    if (d_lines.empty())
    {
        h_lines_.release();
        if (h_votes_.needed())
            h_votes_.release();
        return;
    }

    CV_Assert(d_lines.rows == 2 && d_lines.type() == CV_32FC2);

    h_lines_.create(1, d_lines.cols, CV_32FC2);
    Mat h_lines = h_lines_.getMat();
    d_lines.row(0).download(h_lines);

    if (h_votes_.needed())
    {
        h_votes_.create(1, d_lines.cols, CV_32SC1);
        Mat h_votes = h_votes_.getMat();
        GpuMat d_votes(1, d_lines.cols, CV_32SC1, const_cast<int*>(d_lines.ptr<int>(1)));
        d_votes.download(h_votes);
    }
}

#endif /* !defined (HAVE_CUDA) */