implement optimized version of gpu::BruteForceMatcher::knnMatch when k == 2

modules/gpu/src/brute_force_matcher.cpp

@@ -105,13 +105,13 @@ namespace cv { namespace gpu { namespace bfmatcher
 
     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, cudaStream_t stream);
+        const DevMem2D& mask, const DevMem2Di& trainIdx, const DevMem2Df& distance, const DevMem2Df& allDist, bool cc_12, cudaStream_t stream);
     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, cudaStream_t stream);
+        const DevMem2D& mask, const DevMem2Di& trainIdx, const DevMem2Df& distance, const DevMem2Df& allDist, bool cc_12, cudaStream_t stream);
     template <typename T>
     void knnMatchHamming_gpu(const DevMem2D& queryDescs, const DevMem2D& trainDescs, int knn,
-        const DevMem2D& mask, const DevMem2Di& trainIdx, const DevMem2Df& distance, const DevMem2Df& allDist, cudaStream_t stream);
+        const DevMem2D& mask, const DevMem2Di& trainIdx, const DevMem2Df& distance, const DevMem2Df& allDist, bool cc_12, cudaStream_t stream);
 
     template <typename T>
     void radiusMatchL1_gpu(const DevMem2D& queryDescs, const DevMem2D& trainDescs, float maxDistance,
@@ -428,7 +428,7 @@ void cv::gpu::BruteForceMatcher_GPU_base::knnMatch(const GpuMat& queryDescs, con
     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, cudaStream_t stream);
+        const DevMem2D& mask, const DevMem2Di& trainIdx, const DevMem2Df& distance, const DevMem2Df& allDist, bool cc_12, cudaStream_t stream);
 
     static const match_caller_t match_callers[3][8] =
     {
@@ -454,23 +454,28 @@ void cv::gpu::BruteForceMatcher_GPU_base::knnMatch(const GpuMat& queryDescs, con
 
     ensureSizeIsEnough(nQuery, k, CV_32S, trainIdx);
     ensureSizeIsEnough(nQuery, k, CV_32F, distance);
-    ensureSizeIsEnough(nQuery, nTrain, CV_32FC1, allDist);
+    if (k != 2)
+        ensureSizeIsEnough(nQuery, nTrain, CV_32FC1, allDist);
 
     if (stream)
     {
         stream.enqueueMemSet(trainIdx, Scalar::all(-1));
-        stream.enqueueMemSet(allDist, Scalar::all(numeric_limits<float>::max()));
+        if (k != 2)
+            stream.enqueueMemSet(allDist, Scalar::all(numeric_limits<float>::max()));
     }
     else
     {
         trainIdx.setTo(Scalar::all(-1));
-        allDist.setTo(Scalar::all(numeric_limits<float>::max()));
+        if (k != 2)
+            allDist.setTo(Scalar::all(numeric_limits<float>::max()));
     }
 
     match_caller_t func = match_callers[distType][queryDescs.depth()];
     CV_Assert(func != 0);
+    
+    bool cc_12 = TargetArchs::builtWith(FEATURE_SET_COMPUTE_12) && DeviceInfo().supports(FEATURE_SET_COMPUTE_12);
 
-    func(queryDescs, trainDescs, k, mask, trainIdx, distance, allDist, StreamAccessor::getStream(stream));
+    func(queryDescs, trainDescs, k, mask, trainIdx, distance, allDist, cc_12, StreamAccessor::getStream(stream));
 }
 
 void cv::gpu::BruteForceMatcher_GPU_base::knnMatchDownload(const GpuMat& trainIdx, const GpuMat& distance,

modules/gpu/test/test_features2d.cpp

@@ -320,7 +320,7 @@ TEST_P(BruteForceMatcher, KnnMatch)
     PRINT_PARAM(distStr);
     PRINT_PARAM(dim);
 
-    const int knn = 3;
+    const int knn = 2;
 
     std::vector< std::vector<cv::DMatch> > matches;
 

samples/gpu/performance/tests.cpp

@@ -286,7 +286,7 @@ TEST(BruteForceMatcher)
 {
     // Init CPU matcher
 
-    int desc_len = 128;
+    int desc_len = 64;
 
     BruteForceMatcher< L2<float> > matcher;
 
@@ -328,7 +328,7 @@ TEST(BruteForceMatcher)
     d_matcher.knnMatch(d_query, d_train, d_matches, knn);
     GPU_OFF;
 
-    SUBTEST << "radiusMatch";
+    /*SUBTEST << "radiusMatch";
     float max_distance = 3.8f;
 
     CPU_ON;
@@ -337,7 +337,7 @@ TEST(BruteForceMatcher)
 
     GPU_ON;
     d_matcher.radiusMatch(d_query, d_train, d_matches, max_distance);
-    GPU_OFF;
+    GPU_OFF;*/
 }