Face detection using Haar Cascades on OpenCV 2.4
Create a folder
#include <opencv2/opencv.hpp>
#include <opencv2/objdetect/objdetect.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/legacy/legacy.hpp>
#include <iostream>
#include <stdio.h>
using namespace std;
using namespace cv;
//global variables
String cascade_name = "haarcascade_frontalface_alt.xml";
CascadeClassifier cascade;
//main function
int main(int argc, const char** argv)
{
CvCapture* capture;
Mat frame;
Mat frameout;
//load the cascades
if(!cascade.load(cascade_name)){
printf("--(!)Error loading\n");
return -1;
}
//read the video stream
capture = cvCaptureFromCAM(-1);
if(capture) {
while(true) {
frame = cvQueryFrame(capture);
if(!frame.empty()) {
}
else {
printf(" --(!) No captured frame -- Break!");
break;
}
//FACE DETECTION
std::vector<Rect> faces;
Mat frame_gray;
cvtColor( frame, frame_gray, CV_BGR2GRAY );
equalizeHist( frame_gray, frame_gray );
cascade.detectMultiScale( frame_gray, faces, 1.1, 2, 0|CV_HAAR_SCALE_IMAGE, Size(30, 30) );
for( size_t i = 0; i < faces.size(); i++ ) {
int point1x = faces[i].x;
int point1y = faces[i].y;
int lengthxy = faces[i].width;
rectangle(frame, Point(point1x,point1y), Point(point1x+lengthxy,point1y+lengthxy), Scalar(0,0,255), 1, 8, 0 );
imshow("Face detection", frame );
}
int c = waitKey(10);
if((char)c == 'q') {
break;
}
}
}
return 0;
}
Then, compile:
g++ -I/usr/local/include/opencv -I/usr/local/include/opencv2 -L/usr/local/lib/ -g -o binary facedetector.cpp -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lopencv_imgproc -lopencv_video -lopencv_features2d -lopencv_calib3d -lopencv_objdetect -lopencv_contrib -lopencv_legacy -lopencv_stitching -o facedetector
Finally, run the program:
$ ./facedetector
The command above should show the next result:
