用opencv自带的haar方法进行人脸识别并切割

// FaceRecognize.cpp : 定义控制台应用程序的入口点。

#include "stdafx.h"

#include "opencv2/opencv.hpp"
#include <iostream>
using namespace std;
using namespace cv;

string cascadeName = "D:\\Program Files\\opencv\\data\\haarcascades\\haarcascade_frontalface_alt.xml";

IplImage* cutImage(IplImage* src, CvRect rect) {
cvSetImageROI(src, rect);
IplImage* dst = cvCreateImage(cvSize(rect.width, rect.height),
src->depth,
src->nChannels);

cvCopy(src,dst,0);
cvResetImageROI(src);
return dst;
}

IplImage* detect( Mat& img, CascadeClassifier& cascade, double scale)
{
int i = 0;
double t = 0;
vector<Rect> faces;
Mat gray,smallImg(cvRound (img.rows/scale),cvRound(img.cols/scale), CV_8UC1);

cvtColor(img,gray,CV_BGR2GRAY);
resize(gray,smallImg,smallImg.size(),0,0,INTER_LINEAR);
equalizeHist(smallImg,smallImg);
t=(double)cvGetTickCount();
cascade.detectMultiScale(smallImg,faces,1.3,2,CV_HAAR_SCALE_IMAGE,Size(30,30));
t=(double)cvGetTickCount()-t;
printf("detection time = %g ms\n", t/((double)cvGetTickFrequency()*1000.) );
for( vector<Rect>::const_iterator r = faces.begin(); r != faces.end();r++,i++)
{
IplImage* temp = cutImage(&(IplImage(img)), cvRect(r->x, r->y, 250, 250));// 或 r->width, r->height
return temp;
}
return NULL;
}

int _tmain(int argc, _TCHAR* argv[])
{
CascadeClassifier cascade;
if(!cascade.load(cascadeName))
{
return -1;
}

Mat srcImg, targetImg;
IplImage* faceImage1;
srcImg = imread("1.jpg");
faceImage1 = detect(srcImg,cascade,1);

if (faceImage1 == NULL) {
return -1;
}

cvSaveImage("face.jpg", faceImage1, 0);

cout<<"over";
getchar();
return 0;
}