MSER: all test passed.

1. if a component's variation is a global minimum than it should be a local minimum
2. for the small image with invert and blur, the MSERs number should be 20

modules/features2d/src/mser.cpp

@@ -211,7 +211,7 @@ public:
                         return;
                 }
             }
-            if( parent_ && parent_->var >= 0.f && var >= parent_->var )
+            if( var > 0.f && parent_ && parent_->var >= 0.f && var >= parent_->var )
                 return;
             int xmin = INT_MAX, ymin = INT_MAX, xmax = INT_MIN, ymax = INT_MIN, j = 0;
             wp.msers->push_back(vector<Point>());

modules/features2d/test/test_mser.cpp

@@ -132,7 +132,7 @@ TEST(Features2d_MSER, cases)
             GaussianBlur(src, src, Size(5, 5), 1.5, 1.5);
 
         int minRegs = use_big_image ? 7 : 2;
-        int maxRegs = use_big_image ? 1000 : 15;
+        int maxRegs = use_big_image ? 1000 : 20;
         if( binarize && (thresh == 0 || thresh == 255) )
             minRegs = maxRegs = 0;
 

modules/python/test/test_mser.py

@@ -59,11 +59,11 @@ class mser_test(NewOpenCVTests):
             if blur:
                 src = cv2.GaussianBlur(src, (5, 5), 1.5, 1.5)
             minRegs = 7 if use_big_image else 2
-            maxRegs = 1000 if use_big_image else 15
+            maxRegs = 1000 if use_big_image else 20
             if binarize and (thresh == 0 or thresh == 255):
                 minRegs = maxRegs = 0
             msers, boxes = mserExtractor.detectRegions(src)
             nmsers = len(msers)
             self.assertEqual(nmsers, len(boxes))
             self.assertLessEqual(minRegs, nmsers)
-            self.assertGreaterEqual(maxRegs, nmsers)
+            self.assertGreaterEqual(maxRegs, nmsers)