OpenCV 级联分类器

 #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;

  /** 函数声明 */

  void detectAndDisplay( Mat frame );

  /** 全局变量 */

  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();

  /** @主函数 */

  int main( int argc, const char** argv )

  {

    CvCapture* capture;

    Mat frame;

    //-- 1. 加载级联分类器文件

    if( !face_cascade.load( face_cascade_name ) ){ printf("--(!)Error loading\n"); return -; };

    if( !eyes_cascade.load( eyes_cascade_name ) ){ printf("--(!)Error loading\n"); return -; };

    //-- 2. 打开内置摄像头视频流

    capture = cvCaptureFromCAM( - );

    if( capture )

    {

      while( true )

      {

    frame = cvQueryFrame( capture );

    //-- 3. 对当前帧使用分类器进行检测

        if( !frame.empty() )

        { detectAndDisplay( frame ); }

        else

        { printf(" --(!) No captured frame -- Break!"); break; }

        int c = waitKey();

        if( (char)c == 'c' ) { break; }

       }

    }

    return ;

  }

 /** @函数 detectAndDisplay */

 void detectAndDisplay( Mat frame )

 {

   std::vector<Rect> faces;

   Mat frame_gray;

   cvtColor( frame, frame_gray, CV_BGR2GRAY );

   equalizeHist( frame_gray, frame_gray );

   //-- 多尺寸检测人脸

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

   for( int i = ; 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), , , , Scalar( , ,  ), , ,  );

     Mat faceROI = frame_gray( faces[i] );

     std::vector<Rect> eyes;

     //-- 在每张人脸上检测双眼

     eyes_cascade.detectMultiScale( faceROI, eyes, 1.1, ,  |CV_HAAR_SCALE_IMAGE, Size(, ) );

     for( int j = ; j < eyes.size(); j++ )

      {

        Point center( faces[i].x + eyes[j].x + eyes[j].width*0.5, faces[i].y + eyes[j].y + eyes[j].height*0.5 );

        int radius = cvRound( (eyes[j].width + eyes[i].height)*0.25 );

        circle( frame, center, radius, Scalar( , ,  ), , ,  );

      }

   }

   //-- 显示结果图像

   imshow( window_name, frame );

  }