使用HAAR分类器进行人脸检测

时间:2015-02-23 12:29:59

标签: opencv

我正在使用HAAR分类器在openCV中进行面部检测。这是我的代码

#include "stdafx.h"
#include <opencv2\objdetect\objdetect.hpp>
#include <opencv2\highgui\highgui.hpp>
#include <opencv2\imgproc\imgproc.hpp>
#include <opencv\cv.h>

#include <iostream>
#include <stdio.h>

using namespace std;
using namespace cv;

void detectAndDisplay(Mat frame);


String face_cascade_name = "haarcascade_frontalface_alt.xml";

String eyes_cascade_name = "haarcascade_eye_tree_eyeglasses.xml";


CascadeClassifier face_cascade;
CascadeClassifier eye_cascade;



string window_name = "Capture- Face detection";



int _tmain(int argc, _TCHAR* argv[])
{
    Mat frame = imread("C:/Users/Public/Pictures/Sample Pictures/lena.png");

    imshow("original picture", frame);

    if (face_cascade.load(face_cascade_name))
    {
        cout << "\n Error loading " << endl;
    }

    if (eye_cascade.load(eyes_cascade_name))
    {
        cout << "\n Error Loading " << endl;
    }

    if (!frame.empty())
    {
        detectAndDisplay(frame);
    }

    waitKey(0);


    return 0;
}

void detectAndDisplay(Mat frame)
{
    vector<Rect>faces;

    imshow("lena.png", frame);

    Mat frame_gray;

    cvtColor(frame, frame_gray, CV_BGR2GRAY);

    equalizeHist(frame_gray, frame_gray);

    imshow("Gray Color Image", frame_gray);

    face_cascade.detectMultiScale(frame_gray, faces, 1.1, 2, 0 | CV_HAAR_SCALE_IMAGE, Size(20, 20));

    int k = faces.size();

    for (size_t i = 0; i <faces.size(); i++)
    {
        Point center(faces[i].x + faces[i].width*0.5, faces[i].y + faces[i].height*0.5);

        ellipse(frame, center, Size(faces[i].width*0.5, faces[i].height*0.5), 0, 0, 360, Scalar(255, 0, 0));

        Mat faceROI = frame_gray(faces[i]);

        vector<Rect>eyes;

        eye_cascade.detectMultiScale(faceROI, eyes, 1.1, 2, 0 | CV_HAAR_SCALE_IMAGE, Size(30, 30));

        for (int j = 0; j < eyes.size(); j++)
        {
            Point center(faces[i].x + eyes[j].x + eyes[j].width*0.5, faces[i].y + eyes[j].y + eyes[j].height*0.5);
            int radius = cvRound((eyes[j].width + eyes[j].height)*0.25);
            circle(frame, center, radius, Scalar(0, 0,255), 4, 8, 0);

        }
    }
    imshow(window_name, frame);
}

这里我的代码无效。面部未被检测到。 iam尝试get int k = faces.size()得到'0'值。可能是什么错误。

2 个答案:

答案 0 :(得分:1)

这是因为加载级联的if条件不是逻辑:

你的是:

   if (face_cascade.load(face_cascade_name))
    {
        cout << "\n Error loading " << endl;
    }

    if (eye_cascade.load(eyes_cascade_name))
    {
        cout << "\n Error Loading " << endl;
    }

但它应该是:

    if (!face_cascade.load(face_cascade_name))
    {
        cout << "\n Error loading " << endl;
    }

    if (!eye_cascade.load(eyes_cascade_name))
    {
        cout << "\n Error Loading " << endl;
    }

你忘了'!'在条件。

答案 1 :(得分:0)

当分类器成功加载时,

face_cascade.load(face_cascade_name)显然返回FALSE。您可以在随OpenCV库facedetect.cpp提供的示例中找到它 这就是为什么你没有看到加载过程失败并且你提供了错误的haarcascade文件路径。