From 0ad1d0afacaa8c7d2db7206c7c92bb66f2156b4e Mon Sep 17 00:00:00 2001
From: Alexander Mordvintsev <no@email>
Date: Thu, 22 Sep 2011 08:52:40 +0000
Subject: [PATCH] fixed problem with incorrect distance values returned by
 FlannBasedMatcher for hamming metric (int's were interpreted as floats)

---
 modules/features2d/src/matchers.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/modules/features2d/src/matchers.cpp b/modules/features2d/src/matchers.cpp
index 2a6c66885c..e1c73a0bd5 100755
--- a/modules/features2d/src/matchers.cpp
+++ b/modules/features2d/src/matchers.cpp
@@ -803,7 +803,12 @@ void FlannBasedMatcher::convertToDMatches( const DescriptorCollection& collectio
             {
                 int imgIdx, trainIdx;
                 collection.getLocalIdx( idx, imgIdx, trainIdx );
-                matches[i].push_back( DMatch( i, trainIdx, imgIdx, std::sqrt(dists.at<float>(i,j))) );
+                float dist = 0;
+                if (dists.type() == CV_32S)
+                    dist = static_cast<float>( dists.at<int>(i,j) );
+                else
+                    dist = std::sqrt(dists.at<float>(i,j));
+                matches[i].push_back( DMatch( i, trainIdx, imgIdx, dist ) );
             }
         }
     }