added comments

ppg.cpp

@@ -82,7 +82,7 @@ int main(){
 		{
 			cv::Mat frame_gray;
 			cv::cvtColor(frame, frame_gray, cv::COLOR_BGR2GRAY);
-			//cv::imshow("Gray", frame_gray); //Shows frame in greyscale
+			//cv::imshow("Gray", frame_gray); //Shows frame in greyscale, disabled if as comment
 			std::vector<cv::Rect> faceRectangles;
 			faceDetector.detectMultiScale(frame_gray, faceRectangles, 1.1, 3, 0, cv::Size(20,20)); //Detects face
 			
@@ -143,6 +143,7 @@ int main(){
 					// display green FFT
 					cv::imshow("FFT module green", plotGraph(greenFFTModule, range));
 					
+					//Find max Value and index of said value from FFT 
 					float maxValue=-1;
 					int indexValue=0;
 					for(auto i=0.5*(BUFFER_DURATION);i<(4*BUFFER_DURATION);i++)
@@ -153,6 +154,7 @@ int main(){
 							indexValue=i;
 						}
 					}
+					//Calculate and print Heart Rate Beat Per Minute
 					float HRBPM=(indexValue*60.0)/(BUFFER_DURATION);
 					std::cout<<HRBPM << std::endl;
 				}