temporarily turn off TBB threading when computing SURF descriptors (as the…

temporarily turn off TBB threading when computing SURF descriptors (as the parallel version seems to produce different descriptors on each run)

modules/features2d/src/surf.cpp

@@ -886,9 +886,11 @@ cvExtractSURF( const CvArr* _img, const CvArr* _mask,
 
      
 	if ( N > 0 )
-    cv::parallel_for(cv::BlockedRange(0, N),
-                     cv::SURFInvoker(&params, keypoints, descriptors, img, sum) );
-
+    {
+        //cv::parallel_for(cv::BlockedRange(0, N),
+        //             cv::SURFInvoker(&params, keypoints, descriptors, img, sum) );
+        cv::SURFInvoker(&params, keypoints, descriptors, img, sum)(cv::BlockedRange(0, N));
+    }
 
     /* remove keypoints that were marked for deletion */
     for ( i = 0; i < N; i++ )