diff --git a/modules/contrib/src/basicretinafilter.cpp b/modules/contrib/src/basicretinafilter.cpp
index f6f1c23cc2..52338afaf7 100644
--- a/modules/contrib/src/basicretinafilter.cpp
+++ b/modules/contrib/src/basicretinafilter.cpp
@@ -334,7 +334,8 @@ void BasicRetinaFilter::_localLuminanceAdaptation(const float *inputFrame, const
 	for (register unsigned int IDpixel=0 ; IDpixel<_filterOutput.getNBpixels() ; ++IDpixel, ++inputFramePTR)
 	{
 		float X0=*(localLuminancePTR++)*_localLuminanceFactor+_localLuminanceAddon;
-		*(outputFramePTR++) = (_maxInputValue+X0)**inputFramePTR/(*inputFramePTR +X0);
+		// TODO : the following line can lead to a divide by zero ! A small offset is added, take care if the offset is too large in case of High Dynamic Range images which can use very small values...		
+		*(outputFramePTR++) = (_maxInputValue+X0)**inputFramePTR/(*inputFramePTR +X0+0.00000000001);
 		//std::cout<<"BasicRetinaFilter::inputFrame[IDpixel]=%f, X0=%f, outputFrame[IDpixel]=%f\n", inputFrame[IDpixel], X0, outputFrame[IDpixel]);
 	}
 }
diff --git a/samples/cpp/retinaDemo.cpp b/samples/cpp/retinaDemo.cpp
index b6a592370d..c9fd9729e1 100644
--- a/samples/cpp/retinaDemo.cpp
+++ b/samples/cpp/retinaDemo.cpp
@@ -47,6 +47,8 @@ int main(int argc, char* argv[]) {
 	std::cout<<"* => reports comments/remarks at benoit.alexandre.vision@gmail.com"<<std::endl;
 	std::cout<<"* => more informations and papers at : http://sites.google.com/site/benoitalexandrevision/"<<std::endl;
 	std::cout<<"****************************************************"<<std::endl;
+	std::cout<<" NOTE : this program generates the default retina parameters file 'RetinaDefaultParameters.xml'"<<std::endl;
+	std::cout<<" => you can use this to fine tune parameters and load them if you save to file 'RetinaSpecificParameters.xml'"<<std::endl;
 
 	// basic input arguments checking
 	if (argc<2)
@@ -116,7 +118,10 @@ int main(int argc, char* argv[]) {
 		// save default retina parameters file in order to let you see this and maybe modify it and reload using method "setup"
 		myRetina->write("RetinaDefaultParameters.xml");
 
+		// load parameters if file exists
+		myRetina->setup("RetinaSpecificParameters.xml");
 		myRetina->clearBuffers();
+
 		// declare retina output buffers
 		cv::Mat retinaOutput_parvo;
 		cv::Mat retinaOutput_magno;