Fixed bug #1693. Also corrected default parameters for stitching.

modules/stitching/include/opencv2/stitching/detail/matchers.hpp

@@ -169,7 +169,7 @@ protected:
 class CV_EXPORTS BestOf2NearestMatcher : public FeaturesMatcher
 {
 public:
-    BestOf2NearestMatcher(bool try_use_gpu = false, float match_conf = 0.65f, int num_matches_thresh1 = 6,
+    BestOf2NearestMatcher(bool try_use_gpu = false, float match_conf = 0.3f, int num_matches_thresh1 = 6,
                           int num_matches_thresh2 = 6);
 
     void collectGarbage();

modules/stitching/src/matchers.cpp

@@ -351,9 +351,9 @@ void SurfFeaturesFinder::find(const Mat &image, ImageFeatures &features)
     }
     else
     {
-        vector<float> descriptors;
+        Mat descriptors;
         (*surf)(gray_image, Mat(), features.keypoints, descriptors);
-        features.descriptors = Mat(descriptors, true).reshape(1, (int)features.keypoints.size());
+        features.descriptors = descriptors.reshape(1, (int)features.keypoints.size());
     }
 }
 

samples/cpp/stitching_detailed.cpp

@@ -135,7 +135,7 @@ bool save_graph = false;
 std::string save_graph_to;
 string warp_type = "spherical";
 int expos_comp_type = ExposureCompensator::GAIN_BLOCKS;
-float match_conf = 0.65f;
+float match_conf = 0.3f;
 string seam_find_type = "gc_color";
 int blend_type = Blender::MULTI_BAND;
 float blend_strength = 5;