调用opencv自带的分类器和函数实现人脸检测

#include<opencv2\opencv.hpp>

#include <iostream>

#include <stdio.h>

using namespace std;

using namespace cv;

/** Function Headers */

void detectAndDisplay(Mat frame);

/** Global variables */

String face_cascade_name = "haarcascade_frontalface_default.xml";

String eyes_cascade_name = "haarcascade_eye_tree_eyeglasses.xml";

CascadeClassifier face_cascade;   //定义人脸分类器

CascadeClassifier eyes_cascade;   //定义人眼分类器

String window_name = "Capture - Face detection";

/** @function main */

int main(void)

{

    Mat frame = imread("2.jpg");

    //VideoCapture capture;

    //Mat frame;

    //-- 1. Load the cascades

    if (!face_cascade.load(face_cascade_name)){ printf("--(!)Error loading face cascade\n"); return -1; };

    if (!eyes_cascade.load(eyes_cascade_name)){ printf("--(!)Error loading eyes cascade\n"); return -1; };

    //-- 2. Read the video stream

    //capture.open(0);

    //if (!capture.isOpened()) { printf("--(!)Error opening video capture\n"); return -1; }

    //while (capture.read(frame))

    //{

    //  if (frame.empty())

    //  {

    //      printf(" --(!) No captured frame -- Break!");

    //      break;

    //  }

    //-- 3. Apply the classifier to the frame

    detectAndDisplay(frame);

    int c = waitKey(0);

    if ((char)c == 27) { return 0; } // escape

    //}

    return 0;

}

/** @function detectAndDisplay */

void detectAndDisplay(Mat frame)

{

    std::vector<rect> faces;

    Mat frame_gray;

    cvtColor(frame, frame_gray, COLOR_BGR2GRAY);

    equalizeHist(frame_gray, frame_gray);

    //-- Detect faces

    face_cascade.detectMultiScale(frame_gray, faces, 1.1, 3, CV_HAAR_DO_ROUGH_SEARCH, Size(70, 70),Size(100,100));

    for (size_t i = 0; i < faces.size(); i++)

    {

        //Point center(faces[i].x + faces[i].width / 2, faces[i].y + faces[i].height / 2);

        //ellipse(frame, center, Size(faces[i].width / 2, faces[i].height / 2), 0, 0, 360, Scalar(255, 0, 255), 4, 8, 0);

        rectangle(frame, faces[i],Scalar(255,0,0),2,8,0);

        Mat faceROI = frame_gray(faces[i]);

        std::vector<rect> eyes;

        //-- In each face, detect eyes

        eyes_cascade.detectMultiScale(faceROI, eyes, 1.1, 1, CV_HAAR_DO_ROUGH_SEARCH, Size(3, 3));

        for (size_t j = 0; j < eyes.size(); j++)

        {

            Rect rect(faces[i].x + eyes[j].x, faces[i].y + eyes[j].y, eyes[j].width, eyes[j].height);

            //Point eye_center(faces[i].x + eyes[j].x + eyes[j].width / 2, faces[i].y + eyes[j].y + eyes[j].height / 2);

            //int radius = cvRound((eyes[j].width + eyes[j].height)*0.25);

            //circle(frame, eye_center, radius, Scalar(255, 0, 0), 4, 8, 0);

            rectangle(frame, rect, Scalar(0, 255, 0), 2, 8, 0);

        }

    }

    //-- Show what you got

    namedWindow(window_name, 2);

    imshow(window_name, frame);

}</rect></rect></stdio.h></iostream></opencv2\opencv.hpp>