Accuracy fix for blenaders in stitching module.

modules/stitching/src/blenders.cpp

@@ -476,9 +476,11 @@ static bool ocl_normalizeUsingWeightMap(InputArray _weight, InputOutputArray _ma
 
 void normalizeUsingWeightMap(InputArray _weight, InputOutputArray _src)
 {
-    Mat src = _src.getMat();
+    Mat src;
-    Mat weight = _weight.getMat();
+    Mat weight;
 #ifdef HAVE_TEGRA_OPTIMIZATION
+    src = _src.getMat();
+    weight = _weight.getMat();
     if(tegra::normalizeUsingWeightMap(weight, src))
         return;
 #endif
@@ -488,9 +490,12 @@ void normalizeUsingWeightMap(InputArray _weight, InputOutputArray _src)
             !ocl_normalizeUsingWeightMap(_weight, _src) )
 #endif
     {
+        src = _src.getMat();
+        weight = _weight.getMat();
+
         CV_Assert(src.type() == CV_16SC3);
 
-        if(weight.type() == CV_32FC1)
+        if (weight.type() == CV_32FC1)
         {
             for (int y = 0; y < src.rows; ++y)
             {