     t.stop();
     t.report( "Time for all frames " );
 
-#ifndef NDEBUG
+#ifdef SHOW_TIMING
     for( int i=0; i<num_layers; i++ ) {
         DO_TALK(
           time_gauss[i]->report( "time for Gauss " );

{
    int num_layers = _frame.size();

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


    for( int i=0; i<num_layers; i++ ) {
        bool success;
#ifdef SHOW_TIMING
        time_gauss[i]->start();
        _frame[i]->applyGauss( params ); // async
        time_gauss[i]->stop();
