opencv/modules/gpu/src/brute_force_matcher.cpp

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#include "precomp.hpp"

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

#if !defined (HAVE_CUDA)

cv::gpu::BruteForceMatcher_GPU_base::BruteForceMatcher_GPU_base(DistType) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::add(const vector<GpuMat>&) { throw_nogpu(); }
const vector<GpuMat>& cv::gpu::BruteForceMatcher_GPU_base::getTrainDescriptors() const { throw_nogpu(); return trainDescCollection; }
void cv::gpu::BruteForceMatcher_GPU_base::clear() { throw_nogpu(); }
bool cv::gpu::BruteForceMatcher_GPU_base::empty() const { throw_nogpu(); return true; }
bool cv::gpu::BruteForceMatcher_GPU_base::isMaskSupported() const { throw_nogpu(); return true; }
void cv::gpu::BruteForceMatcher_GPU_base::matchSingle(const GpuMat&, const GpuMat&, GpuMat&, GpuMat&, const GpuMat&) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::matchDownload(const GpuMat&, const GpuMat&, vector<DMatch>&) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::match(const GpuMat&, const GpuMat&, vector<DMatch>&, const GpuMat&) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::makeGpuCollection(GpuMat&, GpuMat&, const vector<GpuMat>&) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::matchCollection(const GpuMat&, const GpuMat&, GpuMat&, GpuMat&, GpuMat&, const GpuMat&) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::matchDownload(const GpuMat&, GpuMat&, const GpuMat&, std::vector<DMatch>&) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::match(const GpuMat&, std::vector<DMatch>&, const std::vector<GpuMat>&) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::knnMatch(const GpuMat&, const GpuMat&, GpuMat&, GpuMat&, GpuMat&, int, const GpuMat&) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::knnMatchDownload(const GpuMat&, const GpuMat&, std::vector< std::vector<DMatch> >&, bool) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::knnMatch(const GpuMat&, const GpuMat&, std::vector< std::vector<DMatch> >&, int, const GpuMat&, bool) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::knnMatch(const GpuMat&, std::vector< std::vector<DMatch> >&, int, const std::vector<GpuMat>&, bool) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::radiusMatch(const GpuMat&, const GpuMat&, GpuMat&, GpuMat&, GpuMat&, float, const GpuMat&) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::radiusMatchDownload(const GpuMat&, const GpuMat&, const GpuMat&, std::vector< std::vector<DMatch> >&, bool) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::radiusMatch(const GpuMat&, const GpuMat&, std::vector< std::vector<DMatch> >&, float, const GpuMat&, bool) { throw_nogpu(); }
void cv::gpu::BruteForceMatcher_GPU_base::radiusMatch(const GpuMat&, std::vector< std::vector<DMatch> >&, float, const std::vector<GpuMat>&, bool) { throw_nogpu(); }

#else /* !defined (HAVE_CUDA) */

namespace cv { namespace gpu { namespace bfmatcher
{
    template <typename T>
    void matchSingleL1_gpu(const DevMem2D& queryDescs, const DevMem2D& trainDescs,
        const DevMem2D& mask, const DevMem2Di& trainIdx, const DevMem2Di& imgIdx, const DevMem2Df& distance);
    template <typename T>
    void matchSingleL2_gpu(const DevMem2D& queryDescs, const DevMem2D& trainDescs,
        const DevMem2D& mask, const DevMem2Di& trainIdx, const DevMem2Di& imgIdx, const DevMem2Df& distance);
    template <typename T>
    void matchCollectionL1_gpu(const DevMem2D& queryDescs, const DevMem2D& trainCollection,
        const DevMem2D_<PtrStep>& maskCollection, const DevMem2Di& trainIdx, const DevMem2Di& imgIdx,
        const DevMem2Df& distance);
    template <typename T>
    void matchCollectionL2_gpu(const DevMem2D& queryDescs, const DevMem2D& trainCollection,
        const DevMem2D_<PtrStep>& maskCollection, const DevMem2Di& trainIdx, const DevMem2Di& imgIdx,
        const DevMem2Df& distance);

    template <typename T>
    void knnMatchL1_gpu(const DevMem2D& queryDescs, const DevMem2D& trainDescs, int knn,
        const DevMem2D& mask, const DevMem2Di& trainIdx, const DevMem2Df& distance, const DevMem2Df& allDist);
    template <typename T>
    void knnMatchL2_gpu(const DevMem2D& queryDescs, const DevMem2D& trainDescs, int knn,
        const DevMem2D& mask, const DevMem2Di& trainIdx, const DevMem2Df& distance, const DevMem2Df& allDist);

    template <typename T>
    void radiusMatchL1_gpu(const DevMem2D& queryDescs, const DevMem2D& trainDescs, float maxDistance,
        const DevMem2D& mask, const DevMem2Di& trainIdx, unsigned int* nMatches, const DevMem2Df& distance);
    template <typename T>
    void radiusMatchL2_gpu(const DevMem2D& queryDescs, const DevMem2D& trainDescs, float maxDistance,
        const DevMem2D& mask, const DevMem2Di& trainIdx, unsigned int* nMatches, const DevMem2Df& distance);
}}}

cv::gpu::BruteForceMatcher_GPU_base::BruteForceMatcher_GPU_base(DistType distType_) : distType(distType_)
{
}

////////////////////////////////////////////////////////////////////
// Train collection

void cv::gpu::BruteForceMatcher_GPU_base::add(const vector<GpuMat>& descCollection)
{
    trainDescCollection.insert(trainDescCollection.end(), descCollection.begin(), descCollection.end());
}

const vector<GpuMat>& cv::gpu::BruteForceMatcher_GPU_base::getTrainDescriptors() const
{
    return trainDescCollection;
}

void cv::gpu::BruteForceMatcher_GPU_base::clear()
{
    trainDescCollection.clear();
}

bool cv::gpu::BruteForceMatcher_GPU_base::empty() const
{
    return trainDescCollection.empty();
}

bool cv::gpu::BruteForceMatcher_GPU_base::isMaskSupported() const
{
    return true;
}

////////////////////////////////////////////////////////////////////
// Match

void cv::gpu::BruteForceMatcher_GPU_base::matchSingle(const GpuMat& queryDescs, const GpuMat& trainDescs,
    GpuMat& trainIdx, GpuMat& distance, const GpuMat& mask)
{
    using namespace cv::gpu::bfmatcher;

    typedef void (*match_caller_t)(const DevMem2D& queryDescs, const DevMem2D& trainDescs,
        const DevMem2D& mask, const DevMem2Di& trainIdx, const DevMem2Di& imgIdx, const DevMem2Df& distance);

    static const match_caller_t match_callers[2][8] =
    {
        {
            matchSingleL1_gpu<unsigned char>, matchSingleL1_gpu<char>, matchSingleL1_gpu<unsigned short>,
            matchSingleL1_gpu<short>, matchSingleL1_gpu<int>, matchSingleL1_gpu<float>, 0, 0
        },
        {
            matchSingleL2_gpu<unsigned char>, matchSingleL2_gpu<char>, matchSingleL2_gpu<unsigned short>,
            matchSingleL2_gpu<short>, matchSingleL2_gpu<int>, matchSingleL2_gpu<float>, 0, 0
        }
    };

    CV_Assert(queryDescs.channels() == 1);
    CV_Assert(trainDescs.cols == queryDescs.cols && trainDescs.type() == queryDescs.type());

    const int nQuery = queryDescs.rows;

    trainIdx.create(1, nQuery, CV_32S);
    distance.create(1, nQuery, CV_32F);

    match_caller_t func = match_callers[distType][queryDescs.depth()];
    CV_Assert(func != 0);

    // For single train there is no need to save imgIdx, so we just save imgIdx to trainIdx.
    // trainIdx store after imgIdx, so we doesn't lose it value.
    func(queryDescs, trainDescs, mask, trainIdx, trainIdx, distance);
}

void cv::gpu::BruteForceMatcher_GPU_base::matchDownload(const GpuMat& trainIdx, const GpuMat& distance,
    vector<DMatch>& matches)
{
    const int nQuery = trainIdx.cols;

    Mat trainIdxCPU = trainIdx;
    Mat distanceCPU = distance;

    matches.clear();
    matches.reserve(nQuery);

    const int* trainIdx_ptr = trainIdxCPU.ptr<int>();
    const float* distance_ptr =  distanceCPU.ptr<float>();
    for (int queryIdx = 0; queryIdx < nQuery; ++queryIdx, ++trainIdx_ptr, ++distance_ptr)
    {
        int trainIdx = *trainIdx_ptr;
        if (trainIdx == -1)
            continue;

        float distance = *distance_ptr;

        DMatch m(queryIdx, trainIdx, 0, distance);

        matches.push_back(m);
    }
}

void cv::gpu::BruteForceMatcher_GPU_base::match(const GpuMat& queryDescs, const GpuMat& trainDescs,
    vector<DMatch>& matches, const GpuMat& mask)
{
    GpuMat trainIdx, distance;
    matchSingle(queryDescs, trainDescs, trainIdx, distance, mask);
    matchDownload(trainIdx, distance, matches);
}

void cv::gpu::BruteForceMatcher_GPU_base::makeGpuCollection(GpuMat& trainCollection, GpuMat& maskCollection,
    const vector<GpuMat>& masks)
{
    if (masks.empty())
    {
        Mat trainCollectionCPU(1, trainDescCollection.size(), CV_8UC(sizeof(DevMem2D)));

        for (size_t i = 0; i < trainDescCollection.size(); ++i)
        {
            const GpuMat& trainDescs = trainDescCollection[i];

            trainCollectionCPU.ptr<DevMem2D>(0)[i] = trainDescs;
        }

        trainCollection.upload(trainCollectionCPU);
    }
    else
    {
        CV_Assert(masks.size() == trainDescCollection.size());

        Mat trainCollectionCPU(1, trainDescCollection.size(), CV_8UC(sizeof(DevMem2D)));
        Mat maskCollectionCPU(1, trainDescCollection.size(), CV_8UC(sizeof(PtrStep)));

        for (size_t i = 0; i < trainDescCollection.size(); ++i)
        {
            const GpuMat& trainDescs = trainDescCollection[i];
            const GpuMat& mask = masks[i];

            CV_Assert(mask.empty() || (mask.type() == CV_8UC1));

            trainCollectionCPU.ptr<DevMem2D>(0)[i] = trainDescs;

            maskCollectionCPU.ptr<PtrStep>(0)[i] = mask;
        }

        trainCollection.upload(trainCollectionCPU);
        maskCollection.upload(maskCollectionCPU);
    }
}

void cv::gpu::BruteForceMatcher_GPU_base::matchCollection(const GpuMat& queryDescs, const GpuMat& trainCollection,
    GpuMat& trainIdx, GpuMat& imgIdx, GpuMat& distance, const GpuMat& maskCollection)
{
    using namespace cv::gpu::bfmatcher;

    typedef void (*match_caller_t)(const DevMem2D& queryDescs, const DevMem2D& trainCollection,
        const DevMem2D_<PtrStep>& maskCollection, const DevMem2Di& trainIdx, const DevMem2Di& imgIdx,
        const DevMem2Df& distance);

    static const match_caller_t match_callers[2][8] =
    {
        {
            matchCollectionL1_gpu<unsigned char>, matchCollectionL1_gpu<char>,
            matchCollectionL1_gpu<unsigned short>, matchCollectionL1_gpu<short>,
            matchCollectionL1_gpu<int>, matchCollectionL1_gpu<float>, 0, 0
        },
        {
            matchCollectionL2_gpu<unsigned char>, matchCollectionL2_gpu<char>,
            matchCollectionL2_gpu<unsigned short>, matchCollectionL2_gpu<short>,
            matchCollectionL2_gpu<int>, matchCollectionL2_gpu<float>, 0, 0
        }
    };

    CV_Assert(queryDescs.channels() == 1);

    const int nQuery = queryDescs.rows;

    trainIdx.create(1, nQuery, CV_32S);
    imgIdx.create(1, nQuery, CV_32S);
    distance.create(1, nQuery, CV_32F);

    match_caller_t func = match_callers[distType][queryDescs.depth()];
    CV_Assert(func != 0);

    func(queryDescs, trainCollection, maskCollection, trainIdx, imgIdx, distance);
}

void cv::gpu::BruteForceMatcher_GPU_base::matchDownload(const GpuMat& trainIdx, GpuMat& imgIdx,
    const GpuMat& distance, vector<DMatch>& matches)
{
    const int nQuery = trainIdx.cols;

    Mat trainIdxCPU = trainIdx;
    Mat imgIdxCPU = imgIdx;
    Mat distanceCPU = distance;

    matches.clear();
    matches.reserve(nQuery);

    const int* trainIdx_ptr = trainIdxCPU.ptr<int>();
    const int* imgIdx_ptr = imgIdxCPU.ptr<int>();
    const float* distance_ptr =  distanceCPU.ptr<float>();
    for (int queryIdx = 0; queryIdx < nQuery; ++queryIdx, ++trainIdx_ptr, ++imgIdx_ptr, ++distance_ptr)
    {
        int trainIdx = *trainIdx_ptr;
        if (trainIdx == -1)
            continue;

        int imgIdx = *imgIdx_ptr;

        float distance = *distance_ptr;

        DMatch m(queryIdx, trainIdx, imgIdx, distance);

        matches.push_back(m);
    }
}

void cv::gpu::BruteForceMatcher_GPU_base::match(const GpuMat& queryDescs, vector<DMatch>& matches,
    const vector<GpuMat>& masks)
{
    GpuMat trainCollection;
    GpuMat maskCollection;

    makeGpuCollection(trainCollection, maskCollection, masks);

    GpuMat trainIdx, imgIdx, distance;

    matchCollection(queryDescs, trainCollection, trainIdx, imgIdx, distance, maskCollection);
    matchDownload(trainIdx, imgIdx, distance, matches);
}

////////////////////////////////////////////////////////////////////
// KnnMatch

void cv::gpu::BruteForceMatcher_GPU_base::knnMatch(const GpuMat& queryDescs, const GpuMat& trainDescs,
    GpuMat& trainIdx, GpuMat& distance, GpuMat& allDist, int k, const GpuMat& mask)
{
    using namespace cv::gpu::bfmatcher;

    typedef void (*match_caller_t)(const DevMem2D& queryDescs, const DevMem2D& trainDescs, int knn,
        const DevMem2D& mask, const DevMem2Di& trainIdx, const DevMem2Df& distance, const DevMem2Df& allDist);

    static const match_caller_t match_callers[2][8] =
    {
        {
            knnMatchL1_gpu<unsigned char>, knnMatchL1_gpu<char>, knnMatchL1_gpu<unsigned short>,
            knnMatchL1_gpu<short>, knnMatchL1_gpu<int>, knnMatchL1_gpu<float>, 0, 0
        },
        {
            knnMatchL2_gpu<unsigned char>, knnMatchL2_gpu<char>, knnMatchL2_gpu<unsigned short>,
            knnMatchL2_gpu<short>, knnMatchL2_gpu<int>, knnMatchL2_gpu<float>, 0, 0
        }
    };

    CV_Assert(queryDescs.channels() == 1);

    const int nQuery = queryDescs.rows;
    const int nTrain = trainDescs.rows;

    trainIdx.create(nQuery, k, CV_32S);
    trainIdx.setTo(Scalar::all(-1));
    distance.create(nQuery, k, CV_32F);

    allDist.create(nQuery, nTrain, CV_32F);

    match_caller_t func = match_callers[distType][queryDescs.depth()];
    CV_Assert(func != 0);

    func(queryDescs, trainDescs, k, mask, trainIdx, distance, allDist);
}

void cv::gpu::BruteForceMatcher_GPU_base::knnMatchDownload(const GpuMat& trainIdx, const GpuMat& distance,
    vector< vector<DMatch> >& matches, bool compactResult)
{
    const int nQuery = distance.rows;
    const int k = trainIdx.cols;

    Mat trainIdxCPU = trainIdx;
    Mat distanceCPU = distance;

    matches.clear();
    matches.reserve(nQuery);

    for (int queryIdx = 0; queryIdx < nQuery; ++queryIdx)
    {
        matches.push_back(vector<DMatch>());
        vector<DMatch>& curMatches = matches.back();
        curMatches.reserve(k);

        int* trainIdx_ptr = trainIdxCPU.ptr<int>(queryIdx);
        float* distance_ptr = distanceCPU.ptr<float>(queryIdx);
        for (int i = 0; i < k; ++i, ++trainIdx_ptr, ++distance_ptr)
        {
            int trainIdx = *trainIdx_ptr;

            if (trainIdx != -1)
            {
                float distance = *distance_ptr;

                DMatch m(queryIdx, trainIdx, 0, distance);

                curMatches.push_back(m);
            }
        }

        if (compactResult && curMatches.empty())
            matches.pop_back();
    }
}

void cv::gpu::BruteForceMatcher_GPU_base::knnMatch(const GpuMat& queryDescs, const GpuMat& trainDescs,
    vector< vector<DMatch> >& matches, int k, const GpuMat& mask, bool compactResult)
{
    GpuMat trainIdx, distance, allDist;
    knnMatch(queryDescs, trainDescs, trainIdx, distance, allDist, k, mask);
    knnMatchDownload(trainIdx, distance, matches, compactResult);
}

namespace
{
    class ImgIdxSetter
    {
    public:
        ImgIdxSetter(int imgIdx_) : imgIdx(imgIdx_) {}
        void operator()(DMatch& m) const {m.imgIdx = imgIdx;}
    private:
        int imgIdx;
    };
}

void cv::gpu::BruteForceMatcher_GPU_base::knnMatch(const GpuMat& queryDescs,
    vector< vector<DMatch> >& matches, int knn, const vector<GpuMat>& masks, bool compactResult)
{
    vector< vector<DMatch> > curMatches;
    vector<DMatch> temp;
    temp.reserve(2 * knn);

    matches.resize(queryDescs.rows);
    for_each(matches.begin(), matches.end(), bind2nd(mem_fun_ref(&vector<DMatch>::reserve), knn));

    for (size_t imgIdx = 0; imgIdx < trainDescCollection.size(); ++imgIdx)
    {
        knnMatch(queryDescs, trainDescCollection[imgIdx], curMatches, knn,
            masks.empty() ? GpuMat() : masks[imgIdx]);

        for (int queryIdx = 0; queryIdx < queryDescs.rows; ++queryIdx)
        {
            vector<DMatch>& localMatch = curMatches[queryIdx];
            vector<DMatch>& globalMatch = matches[queryIdx];

            for_each(localMatch.begin(), localMatch.end(), ImgIdxSetter(imgIdx));

            temp.clear();
            merge(globalMatch.begin(), globalMatch.end(), localMatch.begin(), localMatch.end(), back_inserter(temp));

            globalMatch.clear();
            const size_t count = std::min((size_t)knn, temp.size());
            copy(temp.begin(), temp.begin() + count, back_inserter(globalMatch));
        }
    }

    if (compactResult)
    {
        vector< vector<DMatch> >::iterator new_end = remove_if(matches.begin(), matches.end(),
            mem_fun_ref(&vector<DMatch>::empty));
        matches.erase(new_end, matches.end());
    }
}

////////////////////////////////////////////////////////////////////
// RadiusMatch

void cv::gpu::BruteForceMatcher_GPU_base::radiusMatch(const GpuMat& queryDescs, const GpuMat& trainDescs,
    GpuMat& trainIdx, GpuMat& nMatches, GpuMat& distance, float maxDistance, const GpuMat& mask)
{
    using namespace cv::gpu::bfmatcher;

    typedef void (*radiusMatch_caller_t)(const DevMem2D& queryDescs, const DevMem2D& trainDescs, float maxDistance,
        const DevMem2D& mask, const DevMem2Di& trainIdx, unsigned int* nMatches, const DevMem2Df& distance);

    static const radiusMatch_caller_t radiusMatch_callers[2][8] =
    {
        {
            radiusMatchL1_gpu<unsigned char>, radiusMatchL1_gpu<char>, radiusMatchL1_gpu<unsigned short>,
            radiusMatchL1_gpu<short>, radiusMatchL1_gpu<int>, radiusMatchL1_gpu<float>, 0, 0
        },
        {
            radiusMatchL2_gpu<unsigned char>, radiusMatchL2_gpu<char>, radiusMatchL2_gpu<unsigned short>,
            radiusMatchL2_gpu<short>, radiusMatchL2_gpu<int>, radiusMatchL2_gpu<float>, 0, 0
        }
    };

    CV_Assert(hasAtomicsSupport(getDevice()));

    const int nQuery = queryDescs.rows;
    const int nTrain = trainDescs.rows;

    CV_Assert(queryDescs.channels() == 1);
    CV_Assert(trainDescs.type() == queryDescs.type() && trainDescs.cols == queryDescs.cols);
    CV_Assert(trainIdx.empty() || trainIdx.rows == nQuery);

    nMatches.create(1, nQuery, CV_32SC1);
    nMatches.setTo(Scalar::all(0));
    if (trainIdx.empty())
    {
        trainIdx.create(nQuery, nTrain, CV_32SC1);
        distance.create(nQuery, nTrain, CV_32FC1);
    }

    radiusMatch_caller_t func = radiusMatch_callers[distType][queryDescs.depth()];
    CV_Assert(func != 0);

    func(queryDescs, trainDescs, maxDistance, mask, trainIdx, nMatches.ptr<unsigned int>(), distance);
}

void cv::gpu::BruteForceMatcher_GPU_base::radiusMatchDownload(const GpuMat& trainIdx, const GpuMat& nMatches,
    const GpuMat& distance, std::vector< std::vector<DMatch> >& matches, bool compactResult)
{
    const int nQuery = trainIdx.rows;

    Mat trainIdxCPU = trainIdx;
    Mat nMatchesCPU = nMatches;
    Mat distanceCPU = distance;

    matches.clear();
    matches.reserve(nQuery);

    const unsigned int* nMatches_ptr = nMatchesCPU.ptr<unsigned int>();
    for (int queryIdx = 0; queryIdx < nQuery; ++queryIdx)
    {
        const int* trainIdx_ptr = trainIdxCPU.ptr<int>(queryIdx);
        const float* distance_ptr = distanceCPU.ptr<float>(queryIdx);

        const int nMatches = std::min(static_cast<int>(nMatches_ptr[queryIdx]), trainIdx.cols);

        if (nMatches == 0)
        {
            if (!compactResult)
                matches.push_back(vector<DMatch>());
            continue;
        }

        matches.push_back(vector<DMatch>());
        vector<DMatch>& curMatches = matches.back();
        curMatches.reserve(nMatches);

        for (int i = 0; i < nMatches; ++i, ++trainIdx_ptr, ++distance_ptr)
        {
            int trainIdx = *trainIdx_ptr;

            float distance = *distance_ptr;

            DMatch m(queryIdx, trainIdx, 0, distance);

            curMatches.push_back(m);
        }
        sort(curMatches.begin(), curMatches.end());
    }
}

void cv::gpu::BruteForceMatcher_GPU_base::radiusMatch(const GpuMat& queryDescs, const GpuMat& trainDescs,
    vector< vector<DMatch> >& matches, float maxDistance, const GpuMat& mask, bool compactResult)
{
    GpuMat trainIdx, nMatches, distance;
    radiusMatch(queryDescs, trainDescs, trainIdx, nMatches, distance, maxDistance, mask);
    radiusMatchDownload(trainIdx, nMatches, distance, matches, compactResult);
}

void cv::gpu::BruteForceMatcher_GPU_base::radiusMatch(const GpuMat& queryDescs, vector< vector<DMatch> >& matches,
                float maxDistance, const vector<GpuMat>& masks, bool compactResult)

{
    matches.resize(queryDescs.rows);

    vector< vector<DMatch> > curMatches;

    for (size_t imgIdx = 0; imgIdx < trainDescCollection.size(); ++imgIdx)
    {
        radiusMatch(queryDescs, trainDescCollection[imgIdx], curMatches, maxDistance,
            masks.empty() ? GpuMat() : masks[imgIdx]);

        for (int queryIdx = 0; queryIdx < queryDescs.rows; ++queryIdx)
        {
            vector<DMatch>& localMatch = curMatches[queryIdx];
            vector<DMatch>& globalMatch = matches[queryIdx];

            for_each(localMatch.begin(), localMatch.end(), ImgIdxSetter(imgIdx));

            const size_t oldSize = globalMatch.size();

            copy(localMatch.begin(), localMatch.end(), back_inserter(globalMatch));
            inplace_merge(globalMatch.begin(), globalMatch.begin() + oldSize, globalMatch.end());
        }
    }

    if (compactResult)
    {
        vector< vector<DMatch> >::iterator new_end = remove_if(matches.begin(), matches.end(),
            mem_fun_ref(&vector<DMatch>::empty));
        matches.erase(new_end, matches.end());
    }
}

#endif /* !defined (HAVE_CUDA) */