#include "opencv2/core/core.hpp"
#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;

string face_cascade_name = "haarcascade_frontalface_alt.xml";
CascadeClassifier face_cascade;
string window_name = "人臉識別";

void detectAndDisplay( Mat frame );

int main( int argc, char** argv ){
  Mat image;
  image = imread( argv[1]);

  if( argc != 2 || !image.data ){
    printf("[error] 沒有圖片\n");
    return -1;
  }

  if( !face_cascade.load( face_cascade_name ) ){ 
    printf("[error] 無法加載級聯分類器文件！\n");
    return -1; 
  }

  detectAndDisplay(image);

  waitKey(0);  
}

void detectAndDisplay( Mat frame ){
  std::vector<Rect> faces;
  Mat frame_gray;

  cvtColor( frame, frame_gray, CV_BGR2GRAY );
  equalizeHist( frame_gray, frame_gray );

  face_cascade.detectMultiScale( frame_gray, faces, 1.1, 2, 0|CV_HAAR_SCALE_IMAGE, Size(30, 30) );

  for( int i = 0; i < faces.size(); i++ ){
    Point center( faces[i].x + faces[i].width*0.5, faces[i].y + faces[i].height*0.5 );
    ellipse( frame, center, Size( faces[i].width*0.5, faces[i].height*0.5), 0, 0, 360, Scalar( 255, 0, 255 ), 4, 8, 0 );
  }

  imshow( window_name, frame );
}