diff --git a/corelib/include/rtabmap/core/OdometryEvent.h b/corelib/include/rtabmap/core/OdometryEvent.h
index fe1b0d6b..5c951174 100644
--- a/corelib/include/rtabmap/core/OdometryEvent.h
+++ b/corelib/include/rtabmap/core/OdometryEvent.h
@@ -17,7 +17,7 @@ class OdometryEvent : public UEvent
 {
 public:
 	OdometryEvent(
-		const Image & data, int quality = 0) :
+		const Image & data, int quality = -1) :
 			_data(data),
 			_quality(quality) {}
 	virtual ~OdometryEvent() {}
diff --git a/guilib/src/MainWindow.cpp b/guilib/src/MainWindow.cpp
index af61cb57..aee8aacd 100644
--- a/guilib/src/MainWindow.cpp
+++ b/guilib/src/MainWindow.cpp
@@ -550,7 +550,7 @@ void MainWindow::processOdometry(const rtabmap::Image & data, int quality)
 
 		pose = _lastOdomPose;
 	}
-	else if(quality &&
+	else if(quality>=0 &&
 			_preferencesDialog->getOdomQualityWarnThr() &&
 			quality < _preferencesDialog->getOdomQualityWarnThr())
 	{
@@ -562,7 +562,10 @@ void MainWindow::processOdometry(const rtabmap::Image & data, int quality)
 		UDEBUG("odom ok");
 		_ui->widget_cloudViewer->setBackgroundColor(Qt::black);
 	}
-	_ui->statsToolBox->updateStat("/Odom inliers/", (float)data.id(), (float)quality);
+	if(quality >= 0)
+	{
+		_ui->statsToolBox->updateStat("/Odom inliers/", (float)data.id(), (float)quality);
+	}
 	if(!pose.isNull())
 	{
 		_lastOdomPose = pose;
diff --git a/guilib/src/OdometryViewer.cpp b/guilib/src/OdometryViewer.cpp
index 5a12996e..49a65c46 100644
--- a/guilib/src/OdometryViewer.cpp
+++ b/guilib/src/OdometryViewer.cpp
@@ -23,6 +23,7 @@ namespace rtabmap {
 
 OdometryViewer::OdometryViewer(int maxClouds, int decimation, float voxelSize, int qualityWarningThr, QWidget * parent) :
 		CloudViewer(parent),
+		dataQuality_(-1),
 		lastOdomPose_(Transform::getIdentity()),
 		maxClouds_(maxClouds),
 		voxelSize_(voxelSize),
@@ -50,14 +51,14 @@ OdometryViewer::OdometryViewer(int maxClouds, int decimation, float voxelSize, i
 void OdometryViewer::processData()
 {
 	rtabmap::Image data;
-	int quality = 0;
+	int quality = -1;
 	dataMutex_.lock();
 	if(data_.size())
 	{
 		data = data_.back();
 		data_.clear();
 		quality = dataQuality_;
-		dataQuality_ = 0;
+		dataQuality_ = -1;
 	}
 	dataMutex_.unlock();
 
@@ -109,7 +110,7 @@ void OdometryViewer::processData()
 
 			this->updateCameraPosition(data.pose());
 
-			if(qualityWarningThr_ && quality && quality < qualityWarningThr_)
+			if(qualityWarningThr_ && quality>=0 && quality < qualityWarningThr_)
 			{
 				this->setBackgroundColor(Qt::darkYellow);
 			}