text: /**
   * @file objectDetection2.cpp
   * @author A. Huaman ( based in the classic facedetect.cpp in samples/c )
   * @brief A simplified version of facedetect.cpp, show how to load a cascade classifier and how to find objects (Face + eyes) in a video stream - Using LBP here
   */
  #include "opencv2/objdetect.hpp"
  #include "opencv2/videoio.hpp"
  #include "opencv2/highgui.hpp"
  #include "opencv2/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 = "lbpcascade_frontalface.xml";
  String eyes_cascade_name = "haarcascade_eye_tree_eyeglasses.xml";
  CascadeClassifier face_cascade;
  CascadeClassifier eyes_cascade;
  String window_name = "Capture - Face detection";
  /**
   * @function main
   */
  int main( void )
  {
      VideoCapture capture;
      Mat frame;
  
      //-- 1. Load the cascade
      if( !face_cascade.load( face_cascade_name ) ){ printf("--(!)Error loading face cascade\n"); return -1; };
      if( !eyes_cascade.load( eyes_cascade_name ) ){ printf("--(!)Error loading eyes cascade\n"); return -1; };
  
      //-- 2. Read the video stream
      capture.open( -1 );
      if ( ! capture.isOpened() ) { printf("--(!)Error opening video capture\n"); return -1; }
  
      while ( capture.read(frame) )
      {
          if( frame.empty() )
          {
              printf(" --(!) No captured frame -- Break!");
              break;
          }
  
          //-- 3. Apply the classifier to the frame
          detectAndDisplay( frame );
  
          //-- bail out if escape was pressed
          int c = waitKey(10);
          if( (char)c == 27 ) { 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, Size(80, 80) );
  
      for( size_t i = 0; i < faces.size(); i++ )
      {
          Mat faceROI = frame_gray( faces[i] );
          std::vector<Rect> eyes;
  
          //-- In each face, detect eyes
          eyes_cascade.detectMultiScale( faceROI, eyes, 1.1, 2, 0 |CASCADE_SCALE_IMAGE, Size(30, 30) );
          if( eyes.size() == 2)
          {
              //-- Draw the face
              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, 0 ), 2, 8, 0 );
  
              for( size_t j = 0; j < eyes.size(); j++ )
              { //-- Draw the eyes
                  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, 255 ), 3, 8, 0 );
              }
          }
  
      }
      //-- Show what you got
      imshow( window_name, frame );
  }
  