OpenCV实现人脸检测(face detection) 代码

人脸检测利用detectMultiScale函数和CascadeClassifier(级联分类器);

需要留意的是: VS2012, 利用低版本的OpenCV(如2.4.3)会呈现问题, 导致CascadeClassifier无法加载(load)模子;

进级至OpenCV2.4.7即可, 并利用VS2012的库;

代码如下(VS2012):

#include <opencv.hpp>  
#include <iostream>

#include <iterator>

#include <string>

#include <stdio.h>  
using namespace std;

using namespace cv;  
void detectAndDraw( Mat& img, CascadeClassifier& cascade,

                    CascadeClassifier& nestedCascade,

                    double scale, bool tryflip );  
string cascadeName = "haarcascade_frontalface_alt.xml";

string nestedCascadeName = "haarcascade_eye_tree_eyeglasses.xml";  
int main( int argc, const char** argv )

{

    cv::CascadeClassifier cascade, nestedCascade;

    double scale = 1;

    bool tryflip = true;

    cv::Mat image = imread( "girls.jpg", 1 );

    cascade.load( cascadeName );

    nestedCascade.load( nestedCascadeName );

    detectAndDraw( image, cascade, nestedCascade, scale, tryflip);

    cv::waitKey(0);

    return 0;

}  
void detectAndDraw( Mat& img, CascadeClassifier& cascade,

                    CascadeClassifier& nestedCascade,

                    double scale, bool tryflip )

{

    int i = 0;

    double t = 0;

    vector<Rect> faces, faces2;

    const static Scalar 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)} ;

    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 );

    //