opencv的haar特征进行人脸识别

#include "cv.h" 
#include "highgui.h"
#include <stdio.h> 
#include <stdlib.h> 
#include <string.h> 
#include <assert.h> 
#include <math.h> 
#include <float.h> 
#include <limits.h> 
#include <time.h> 
#include <ctype.h>
#ifdef _EiC 
#define WIN32 
#endif
static CvMemStorage* storage = 0;
static CvHaarClassifierCascade* cascade = 0;
void detect_and_draw(IplImage* image);
const char* cascade_name =
"D:\\Program Files (x86)\\opencv\\data\\haarcascades\\haarcascade_frontalface_alt.xml";
/*    "haarcascade_profileface.xml";*/

int main(int argc, char** argv)
{
 cascade_name = "D:\\Program Files (x86)\\opencv\\data\\haarcascades\\haarcascade_frontalface_alt2.xml";
 cascade = (CvHaarClassifierCascade*)cvLoad(cascade_name, 0, 0, 0);
 if (!cascade)
 {
  fprintf(stderr, "ERROR: Could not load classifier cascade\n");
  return -1;
 }
 storage = cvCreateMemStorage(0);
 cvNamedWindow("result", 1);
 const char* filename = "G:\\pic.bmp";
 IplImage* image = cvLoadImage(filename, 1);
 if (image)
 {
  detect_and_draw(image);
  cvWaitKey(0);
  cvReleaseImage(&image);
 }
 cvDestroyWindow("result");
 system("pause");
 return 0;
}

void detect_and_draw(IplImage* img)
{
 double scale = 1.2;
 static CvScalar colors[] = 
 {
  CV_RGB(0, 0, 255),
  CV_RGB(0, 128, 255),
  CV_RGB(0, 255, 255),
  CV_RGB(0, 255, 0),
  CV_RGB(255, 128, 0),
  CV_RGB(255, 255, 0),
  CV_RGB(255, 0, 0),
  CV_RGB(255, 0, 255)
 };//Just some pretty colors to draw with
  
 // 
 IplImage* gray = cvCreateImage(cvSize(img->width, img->height), 8, 1);
IplImage* small_img = cvCreateImage(cvSize(cvRound(img->width / scale), cvRound(img->height / scale)), 8, 1);
 cvCvtColor(img, gray, CV_BGR2GRAY);
 cvResize(gray, small_img, CV_INTER_LINEAR);
 cvEqualizeHist(small_img, small_img); //进行直方图均衡化
//Detect objects if any 
 // 
 cvClearMemStorage(storage);
 double t = (double)cvGetTickCount();
 CvSeq* objects = cvHaarDetectObjects(small_img,
  cascade,
  storage,
  1.1,
  2,
  0/*CV_HAAR_DO_CANNY_PRUNING*/,
  cvSize(30, 30));
 t = (double)cvGetTickCount() - t;
 printf("detection time = %gms\n", t / ((double)cvGetTickFrequency()*1000.));
 //Loop through found objects and draw boxes around them 
 for (int i = 0; i<(objects ? objects->total : 0); ++i)
 {
  CvRect* r = (CvRect*)cvGetSeqElem(objects, i);
  cvRectangle(img, cvPoint(r->x*scale, r->y*scale), cvPoint((r->x + r->width)*scale, (r->y + r->height)*scale), colors[i % 8]);
 }
 for (int i = 0; i < (objects ? objects->total : 0); i++)
 {
  CvRect* r = (CvRect*)cvGetSeqElem(objects, i);
  CvPoint center;
  int radius;
  center.x = cvRound((r->x + r->width*0.5)*scale);
  center.y = cvRound((r->y + r->height*0.5)*scale);
  radius = cvRound((r->width + r->height)*0.25*scale);
  cvCircle(img, center, radius, colors[i % 8], 3, 8, 0);
 }
 cvShowImage("result", img);
 cvReleaseImage(&gray);
 cvReleaseImage(&small_img);
}