Example
C++
#include "opencv2/objdetect/objdetect.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
#include <stdio.h>
using namespace std;
using namespace cv;
// Function Headers
void detectAndDisplay(Mat frame);
// Global variables
string face_cascade_name = "./data/haarcascade_frontalface_alt2.xml";
CascadeClassifier face_cascade;
// Function main
int main(void)
{
// Load the cascade
if (!face_cascade.load(face_cascade_name)){
printf("--(!)Error on cascade loading\n");
return (-1);
}
// Read the image file
Mat frame = imread("d:/obama_01.jpg");
// Apply the classifier to the frame
if (!frame.empty())
detectAndDisplay(frame);
waitKey(0);
return 0;
}
// Function detectAndDisplay
void detectAndDisplay(Mat frame)
{
std::vector<Rect> faces;
Mat frame_gray;
cvtColor(frame, frame_gray, COLOR_BGR2GRAY);
equalizeHist(frame_gray, frame_gray);
// Detect faces
face_cascade.detectMultiScale(frame_gray, faces, 1.1, 2, 0 | CASCADE_SCALE_IMAGE, Size(30, 30));
for (int ic = 0; ic < faces.size(); ic++) // Iterate through all current elements (detected faces)
{
Point pt1(faces[ic].x, faces[ic].y); // Display detected faces on main window - live stream from camera
Point pt2((faces[ic].x + faces[ic].height), (faces[ic].y + faces[ic].width));
rectangle(frame, pt1, pt2, Scalar(0, 255, 0), 2, 8, 0);
}
imshow("original", frame);
}
