 
     for( int i=0; i<num_layers; i++ ) {
         bool success;
+        #ifndef NDEBUG
         time_gauss[i]->start();
+        #endif // not NDEBUG
         _frame[i]->applyGauss( params ); // async
+        #ifndef NDEBUG
         time_gauss[i]->stop();
-        POP_CHK_CALL_IFSYNC;
-
+        #endif // not NDEBUG
+        POP_CHK_CALL_IFSYNC;
+
+        #ifndef NDEBUG
         time_mag[i]->start();
+        #endif // not NDEBUG
         _frame[i]->applyMag(   params );  // async
+        #ifndef NDEBUG
         time_mag[i]->stop();
-        POP_CHK_CALL_IFSYNC;
-
+        #endif // not NDEBUG
+        POP_CHK_CALL_IFSYNC;
+
+        #ifndef NDEBUG
         time_hyst[i]->start();
+        #endif // not NDEBUG
         _frame[i]->applyHyst(  params );  // async
+        #ifndef NDEBUG
         time_hyst[i]->stop();
-        POP_CHK_CALL_IFSYNC;
-
+        #endif // not NDEBUG
+        POP_CHK_CALL_IFSYNC;
+
+        #ifndef NDEBUG
         time_thin[i]->start();
+        #endif // not NDEBUG
         _frame[i]->applyThinning(  params );  // async
+        #ifndef NDEBUG
         time_thin[i]->stop();
-        POP_CHK_CALL_IFSYNC;
-
+        #endif // not NDEBUG
+        POP_CHK_CALL_IFSYNC;
+
+        #ifndef NDEBUG
         time_desc[i]->start();
+        #endif // not NDEBUG
         success = _frame[i]->applyDesc(  params );  // async
+        #ifndef NDEBUG
         time_desc[i]->stop();
+        #endif // not NDEBUG
         POP_CHK_CALL_IFSYNC;
 
         if( not success ) continue;
 
+        #ifndef NDEBUG
         time_vote[i]->start();
+        #endif // not NDEBUG
         _frame[i]->applyVote(  params );  // async
+        #ifndef NDEBUG
         time_vote[i]->stop();
+        #endif // not NDEBUG
         POP_CHK_CALL_IFSYNC;
         // _frame[i]->applyLink(  params );  // async
     }

        time_thin [i]->report( "time for Thin  " );
        time_desc [i]->report( "time for Desc  " );
        time_vote [i]->report( "time for Vote  " );
    }

    // cerr << "Leave " << __FUNCTION__ << endl;
}


    int num_layers = _frame.size();

#ifndef NDEBUG
    KeepTime* time_gauss[num_layers];
    KeepTime* time_mag  [num_layers];
    KeepTime* time_hyst [num_layers];
