Merge pull request opencv#7879 from alalek:backport_7852

alalek · alalek · commit c7ae26bf2481 · 2016-12-16T13:19:58.000Z
diff --git a/modules/features2d/src/orb.cpp b/modules/features2d/src/orb.cpp
@@ -736,7 +736,9 @@ void ORB::operator()( InputArray _image, InputArray _mask, vector<KeyPoint>& _ke
     //ROI handling
     const int HARRIS_BLOCK_SIZE = 9;
     int halfPatchSize = patchSize / 2;
-    int border = std::max(edgeThreshold, std::max(halfPatchSize, HARRIS_BLOCK_SIZE/2))+1;
+    // sqrt(2.0) is for handling patch rotation
+    int descPatchSize = cvCeil(halfPatchSize*sqrt(2.0));
+    int border = std::max(edgeThreshold, std::max(descPatchSize, HARRIS_BLOCK_SIZE/2))+1;
 
     Mat image = _image.getMat(), mask = _mask.getMat();
     if( image.type() != CV_8UC1 )
