fixed bug in graphcut seam estimation (opencv_stitching)

modules/stitching/matchers.cpp

@@ -69,6 +69,7 @@ namespace
         inline GpuSurfFeaturesFinder(double hess_thresh, int num_octaves, int num_layers, 
                                      int num_octaves_descr, int num_layers_descr) 
         {
+            surf_.keypointsRatio = 0.1f;
             surf_.hessianThreshold = hess_thresh;
             surf_.extended = false;
             num_octaves_ = num_octaves;

modules/stitching/seam_finders.cpp

@@ -232,9 +232,15 @@ void GraphCutSeamFinder::Impl::findInPair(const Mat &img1, const Mat &img2, Poin
         for (int x = 0; x < roi.width; ++x)
         {
             if (graph.inSourceSegment((y + gap) * (roi.width + 2 * gap) + x + gap))
-                mask2.at<uchar>(roi.y - tl2.y + y, roi.x - tl2.x + x) = 0;
+            {
+                if (mask1.at<uchar>(roi.y - tl1.y + y, roi.x - tl1.x + x))
+                    mask2.at<uchar>(roi.y - tl2.y + y, roi.x - tl2.x + x) = 0;
+            }
             else
-                mask1.at<uchar>(roi.y - tl1.y + y, roi.x - tl1.x + x) = 0;
+            {
+                if (mask2.at<uchar>(roi.y - tl2.y + y, roi.x - tl2.x + x))
+                    mask1.at<uchar>(roi.y - tl1.y + y, roi.x - tl1.x + x) = 0;
+            }
         }
     }
 }