利用opencv进行面部和眼睛检测

#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 */
//-- Note, either copy these two files from opencv/data/haarscascades to your current folder, or change these locations
String face_cascade_name = "haarcascade_frontalface_alt.xml";
String eyes_cascade_name = "haarcascade_eye_tree_eyeglasses.xml";
CascadeClassifier face_cascade;
CascadeClassifier eyes_cascade;
string window_name = "Capture - Face detection";
RNG rng(12345);
/**
 * @function main
 */
int main( void )
{
  VideoCapture capture;
  Mat frame;
  //-- 1. Load the cascades
  if( !face_cascade.load( face_cascade_name ) ){ printf("--(!)Error loading\n"); return -1; };
  if( !eyes_cascade.load( eyes_cascade_name ) ){ printf("--(!)Error loading\n"); return -1; };
  //-- 2. Read the video stream
  capture.open( /*-1*/0 );
  if( capture.isOpened() )
  {
    for(;;)
    {
      capture >> frame;
      //-- 3. Apply the classifier to the frame
      if( !frame.empty() )
       {
          detectAndDisplay( frame );
//          imshow( window_name, frame );
      }
      else
       { printf(" --(!) No captured frame -- Break!"); break; }
      int c = waitKey(10);
      if( (char)c == 'c' ) { break; }
    }
  }
  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|CV_HAAR_SCALE_IMAGE, Size(30, 30) );
   for( size_t i = 0; i < faces.size(); i++ )
    {
      Point center( faces[i].x + faces[i].width/2, faces[i].y + faces[i].height/2 );
      ellipse( frame, center, Size( faces[i].width/2, faces[i].height/2), 0, 0, 360, Scalar( 255, 0, 255 ), 2, 8, 0 );
      Mat faceROI = frame_gray( faces[i] );
      std::vector<Rect> eyes;
      //-- In each face, detect eyes
      eyes_cascade.detectMultiScale( faceROI, eyes, 1.1, 2, 0 |CV_HAAR_SCALE_IMAGE, Size(30, 30) );
      for( size_t j = 0; j < eyes.size(); j++ )
       {
         Point eye_center( faces[i].x + eyes[j].x + eyes[j].width/2, faces[i].y + eyes[j].y + eyes[j].height/2 );
         int radius = cvRound( (eyes[j].width + eyes[j].height)*0.25 );
         circle( frame, eye_center, radius, Scalar( 255, 0, 0 ), 3, 8, 0 );
       }
    }
   //-- Show what you got
   imshow( window_name, frame );
}