Reverted BORDER_CONSTAT in stitcher.cpp

Resolves #7251

modules/stitching/src/stitcher.cpp

@@ -192,7 +192,7 @@ Stitcher::Status Stitcher::composePanorama(InputArrayOfArrays images, OutputArra
         K(1,1) *= (float)seam_work_aspect_;
         K(1,2) *= (float)seam_work_aspect_;
 
-        corners[i] = w->warp(seam_est_imgs_[i], K, cameras_[i].R, INTER_LINEAR, BORDER_CONSTANT, images_warped[i]);
+        corners[i] = w->warp(seam_est_imgs_[i], K, cameras_[i].R, INTER_LINEAR, BORDER_REFLECT, images_warped[i]);
         sizes[i] = images_warped[i].size();
 
         w->warp(masks[i], K, cameras_[i].R, INTER_NEAREST, BORDER_CONSTANT, masks_warped[i]);
@@ -298,7 +298,7 @@ Stitcher::Status Stitcher::composePanorama(InputArrayOfArrays images, OutputArra
         int64 pt = getTickCount();
 #endif
         // Warp the current image
-        w->warp(img, K, cameras_[img_idx].R, INTER_LINEAR, BORDER_CONSTANT, img_warped);
+        w->warp(img, K, cameras_[img_idx].R, INTER_LINEAR, BORDER_REFLECT, img_warped);
         LOGLN(" warp the current image: " << ((getTickCount() - pt) / getTickFrequency()) << " sec");
 #if ENABLE_LOG
         pt = getTickCount();