Face Detection using OpenCV

/**
 * @file facedetect.cpp
 * @author Karan Thakkar
 * @brief Uses the Haar Cascade Classifier to detect face and eyes in a video feed
 */

#include "stdafx.h"
#include "opencv2/objdetect/objdetect.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"

#include <iostream>

using namespace std;
using namespace cv;

/** Function Headers */
void detectAndDisplay(IplImage* frame );

/** Global variables */
CvHaarClassifierCascade* face_cascade = 0;
CvHaarClassifierCascade* eye_cascade = 0;
CvMemStorage* pStorageface = 0;
CvMemStorage* pStorageeye = 0;        // memory for detector to use

RNG rng(12345);

/**
 * @function main
 */
int main( int argc, const char** argv )
{
  CvCapture* capture;
  IplImage* frame = 0;

  //-- 1. Load the cascade
  face_cascade = (CvHaarClassifierCascade *)cvLoad("C:\\OpenCV-2.4.2\\opencv\\data\\haarcascades\\haarcascade_frontalface_alt_tree.xml", 0 , 0, 0);
  eye_cascade = (CvHaarClassifierCascade *)cvLoad("C:\\OpenCV-2.4.2\\opencv\\data\\haarcascades\\haarcascade_eye_tree_eyeglasses.xml", 0 , 0, 0);

  while( true )
    {

        //-- 2. Read the video stream
        capture = cvCaptureFromCAM(1);
        frame = cvQueryFrame( capture );

      //-- 3. Apply the classifier to the frame
      detectAndDisplay(frame);

      int c = waitKey(10);
      if( (char)c == 27 ) { exit(0); }

    }

  // clean up and release resources
    cvReleaseImage(&frame);
    if(face_cascade) cvReleaseHaarClassifierCascade(&face_cascade);
    if(pStorageface) cvReleaseMemStorage(&pStorageface);
    if(pStorageeye) cvReleaseMemStorage(&pStorageeye);

    return 0;

}

/**
 * @function detectAndDisplay
 */
void detectAndDisplay(IplImage* frame )
{

   CvSeq * pFaceRectSeq;               // memory-access interface
   CvSeq * pEyeRectSeq;
   pStorageface = cvCreateMemStorage(0);

    // detect faces in image
    pFaceRectSeq = cvHaarDetectObjects
        (frame, face_cascade, pStorageface,
        1.1,                       // increase search scale by 10% each pass
        3,                         // merge groups of three detections
        CV_HAAR_DO_CANNY_PRUNING,  // skip regions unlikely to contain a face
        cvSize(40,40));            // smallest size face to detect = 40x40

    pStorageeye = cvCreateMemStorage(0);

    // detect faces in image
    pEyeRectSeq = cvHaarDetectObjects
        (frame, eye_cascade, pStorageeye,
        1.1,                       // increase search scale by 10% each pass
        3,                         // merge groups of three detections
        CV_HAAR_DO_CANNY_PRUNING,  // skip regions unlikely to contain a face
        cvSize(40,40));            // smallest size face to detect = 40x40


   const char * DISPLAY_WINDOW = "Haar Window";
    int i;

    // create a window to display detected faces
    cvNamedWindow(DISPLAY_WINDOW, CV_WINDOW_AUTOSIZE);

    // draw a rectangular outline around each detection
    for(i=0;i<(pFaceRectSeq? pFaceRectSeq->total:0); i++ )
    {
        CvRect* r = (CvRect*)cvGetSeqElem(pFaceRectSeq, i);
        CvPoint pt1 = { r->x, r->y };
        CvPoint pt2 = { r->x + r->width, r->y + r->height };
        cvRectangle(frame, pt1, pt2, CV_RGB(255,255,255), 3, 4, 0);
    }

    // draw a rectangular outline around each detection
    for(i=0;i<(pEyeRectSeq? pEyeRectSeq->total:0); i++ )
    {
        CvRect* r = (CvRect*)cvGetSeqElem(pEyeRectSeq, i);
        CvPoint pt1 = { r->x, r->y };
        CvPoint pt2 = { r->x + r->width, r->y + r->height };
        cvRectangle(frame, pt1, pt2, CV_RGB(255,255,255), 3, 4, 0);
    }

    // display face detections
    cvShowImage(DISPLAY_WINDOW, frame);
}