opencv自带的haar分类器进行人脸识别

1、识别一幅图片中的人脸个数，这里采用的是绝对路径，可自行修改

   

#include <cstdio>  
#include <cstdlib>  
#include <>  
#include <vector>  
#include <iostream>  
#include <string>  
#include <opencv2\>  

using namespace std;
using namespace cv;

int main(int argc, char* argv[])
{

	//加载Haar特征检测分类器  
	CascadeClassifier cascade;
	("D:\\Program Files\\opencv\\sources\\data\\haarcascades\\haarcascade_frontalface_alt2.xml");

	// 载入图像  
	const string pstrImageName = "E:\\";
	Mat SrcImage = imread(pstrImageName, CV_LOAD_IMAGE_COLOR);
	Mat GrayImage;

	cvtColor(SrcImage, GrayImage, CV_BGR2GRAY);

	 //人脸识别与标记  
	if (())
		cout << "未加载分类器" << endl;
	
		CvScalar FaceCirclecolors[] =
		{
			{ { 0, 0, 255 } },
			{ { 0, 128, 255 } },
			{ { 0, 255, 255 } },
			{ { 0, 255, 0 } },
			{ { 255, 128, 0 } },
			{ { 255, 255, 0 } },
			{ { 255, 0, 0 } },
			{ { 255, 0, 255 } }
		};

		vector<cv::Rect> faces;

		DWORD dwTimeBegin, dwTimeEnd;
		dwTimeBegin = GetTickCount();
		// 识别  
		(GrayImage, faces);
		dwTimeEnd = GetTickCount();

		cout << "人脸个数:" << () - ()
			<< "识别用时:" << dwTimeEnd - dwTimeBegin << "ms\n";
		// 标记  
		int n = 0;
		for (vector<cv::Rect>::const_iterator i = (); i <(); i++, n++)
		{
			Point center;
			int radius;
			 = cvRound((i->x + i->width * 0.5));
			 = cvRound((i->y + i->height * 0.5));
			radius = cvRound((i->width + i->height) * 0.25);
			circle(SrcImage, center, radius, FaceCirclecolors[n % 8], 2);
		}
	

	imshow("src", SrcImage);
	waitKey();

}

2、从视频流中识别人脸

#include "opencv2/objdetect/"
#include "opencv2/highgui/"
#include "opencv2/imgproc/"

#include <iostream>
#include <>

using namespace std;
using namespace cv;


/** 全局变量 */

CascadeClassifier face_cascade;
CascadeClassifier eyes_cascade;
CvScalar FaceCirclecolors[] =
{
	{ { 0, 0, 255 } },
	{ { 0, 128, 255 } },
	{ { 0, 255, 255 } },
	{ { 0, 255, 0 } },
	{ { 255, 128, 0 } },
	{ { 255, 255, 0 } },
	{ { 255, 0, 0 } },
	{ { 255, 0, 255 } }
};

/** @主函数 */
int main(int argc, const char** argv)
{
		
	face_cascade.load("D:\\Program Files\\opencv\\sources\\data\\haarcascades\\haarcascade_frontalface_alt.xml");
	if (face_cascade.empty())
		cout << "face error loading" << endl;


	VideoCapture capture(0);
	Mat frame;
			
		while (1)
		{
			capture >> frame;
			
			if (())
				cout << "error" << endl;
						
				vector<cv::Rect> faces;
				Mat GrayImage;
				cvtColor(frame, GrayImage, CV_BGR2GRAY);
				// 识别  
				face_cascade.detectMultiScale(GrayImage, faces);

				// 标记  
				int n = 0;
				for (vector<cv::Rect>::const_iterator i = (); i!=(); i++, n++)
				{
					Point center;
					int radius;
					 = cvRound((i->x + i->width * 0.5));
					 = cvRound((i->y + i->height * 0.5));
					radius = cvRound((i->width + i->height) * 0.25);
					circle(frame, center, radius, FaceCirclecolors[n % 8], 2);
				}
								
				imshow("video", frame);
				waitKey(10);
		}
	
	return 0;
}