diff --git a/src/processor/processor_visual_odometry.cpp b/src/processor/processor_visual_odometry.cpp
index 1d8238d83c98c5971df0f2c02a7e79c7309b9e7c..cf33dbcdf2ab2741f76db8921c08a5d5db441023 100644
--- a/src/processor/processor_visual_odometry.cpp
+++ b/src/processor/processor_visual_odometry.cpp
@@ -132,11 +132,7 @@ void ProcessorVisualOdometry::preProcess()
         capture_image_incoming_->setTracksPrev(tracks_init);
 
         // print a bar with the number of active tracks in incoming
-        std::string s;
-        for (int i = 0; i<capture_image_incoming_->getKeyPoints().size(); i++)
-        {
-           s += "#";
-        }
+        std::string s(capture_image_incoming_->getKeyPoints().size(), '#');
         WOLF_INFO("TRACKS: ", capture_image_incoming_->getKeyPoints().size(), " ", s);
 
         auto __attribute__((unused)) dt_preprocess = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now() - t1).count();
@@ -314,11 +310,7 @@ void ProcessorVisualOdometry::preProcess()
     auto __attribute__((unused)) dt_preprocess = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now() - t1).count();
 
     // print a bar with the number of active tracks in incoming
-    std::string s;
-    for (int i = 0; i<capture_image_incoming_->getKeyPoints().size(); i++)
-    {
-       s += "#";
-    }
+    std::string s(capture_image_incoming_->getKeyPoints().size(), '#');
     WOLF_INFO("TRACKS: ", capture_image_incoming_->getKeyPoints().size(), " ", s);
 
     WOLF_DEBUG( "dt_preprocess (ms): " , dt_preprocess );