diff --git a/ppg.cpp b/ppg.cpp
index 0e1b1cc..564d9c6 100644
--- a/ppg.cpp
+++ b/ppg.cpp
@@ -82,13 +82,22 @@ int main(){
 			cv::Mat greenSignal(1, FPS*BUFFER_DURATION, CV_64F); 
 			if (!isBufferFull)
 			{
-			greenSignal.at<double>(0, sampleIdBuffer) = avg_forehead[1] ;
-			sampleIdBuffer++;
-			if (sampleIdBuffer == FPS*BUFFER_DURATION)
+				greenSignal.at<double>(0, sampleIdBuffer) = avg_forehead[1] ;
+				sampleIdBuffer++;
+				if (sampleIdBuffer == FPS*BUFFER_DURATION)
 				{
 				isBufferFull = true;
 				}
 			}
+
+			//Normalisation of our signal
+			std::vector<double> greenSignalNormalized; 
+			cv::Scalar mean, stddev;
+			cv::meanStdDev(greenSignal, mean, stddev);
+			for (int l_sample=0; l_sample < FPS*BUFFER_DURATION; l_sample++)
+			{
+				greenSignalNormalized.push_back((greenSignal.at<double>(0, l_sample)-mean))
+			}
 		}
 	}	
 }