updated to turn video to grey for face recognition

ppg.cpp

@@ -11,6 +11,7 @@ int DISCARD_DURATION=5;
 bool isDiscardData=true;
 int countDiscard=0;
 
+
 int main(){ 
 	//Print "PPG algorithm" to terminal
 	//Note to self: std::endl; returns to line in terminal; use it everytime when done printing something.
@@ -25,6 +26,13 @@ int main(){
 		return -2;
 	}
 		
+	cv::CascadeClassifier faceDetector;
+	if(!faceDetector.load("./haarcascade_frontalface_alt.xml"))
+	{
+		std::cerr<<"[ERROR] Unable to load face cascade"<<std::endl;
+		return -1;
+	};	
+		
 	while (true)
 	{
 		if(isDiscardData)
@@ -49,12 +57,16 @@ int main(){
 				break;
 			}
 			cv::imshow("Color", frame);
-			
 			if (cv::waitKey(1000.0/FPS)>=0)
 			{ 
 			break;
-
 			}
+			
+			cv::Mat frame_gray;
+			cv::cvtColor(frame, frame_gray, cv::COLOR_BGR2GRAY);
+			cv::imshow("Gray", frame_gray);
+			std::vector<cv::Rect> faceRectangles;
+			faceDetector.detectMultiScale(frame_gray, faceRectangles, 1.1, 3, 0, cv::Size(20,20));
 		}
 	}	
 }