camer.cpp

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

void Pic2Gray(Mat camerFrame,Mat &gray)
{
	//普通台式机3通道BGR,移动设备为4通道
	if (camerFrame.channels() == 3)
	{
		cvtColor(camerFrame, gray, CV_BGR2GRAY);
	}
	else if (camerFrame.channels() == 4)
	{
		cvtColor(camerFrame, gray, CV_BGRA2GRAY);
	}
	else
		gray = camerFrame;
}

int main()
{
	//加载Haar人脸检测器
	CascadeClassifier faceDetector;
	std::string faceCascadeFilename = "haarcascade_frontalface_default.xml";

	//错误信息提示
	try{
		faceDetector.load(faceCascadeFilename);
	}
	catch (cv::Exception e){}
	if (faceDetector.empty())
	{
		std::cerr << "脸部检测器不能加载 (";
		std::cerr << faceCascadeFilename << ")!" << std::endl;
		exit(1);
	}

	//打开摄像头
	VideoCapture cap(0);
	while (true)
	{
		Mat camerFrame;
		cap >> camerFrame;
		if (camerFrame.empty())
		{
			std::cerr << "无法获取摄像头图像" << std::endl;
			getchar();
			exit(1);
		}
		Mat displayedFrame(camerFrame.size(),CV_8UC3);


		//人脸检测只适用于灰度图像
		Mat gray;
		Pic2Gray(camerFrame, gray);



		//直方图均匀化(改善图像的对比度和亮度)
		Mat equalizedImg;
		equalizeHist(gray, equalizedImg);

		//人脸检测用Cascade Classifier::detectMultiScale来进行人脸检测

		//int flags = CASCADE_FIND_BIGGEST_OBJECT|CASCADE_DO_ROUGH_SEARCH;//只检测脸最大的人
		int flags = CASCADE_SCALE_IMAGE;	//检测多个人
		Size minFeatureSize(30, 30);//最小检测区域，越小对cpu要求越高，检测越准确
		float searchScaleFactor = 1.1f;//每次检测后，检测区域扩增比，越小（不小于等于1）对cpu要求越高，检测越准确
		int minNeighbors = 4;//在同一区域识别人脸次数，越大越消耗cpu，检测越准确
		std::vector<Rect> faces;
		faceDetector.detectMultiScale(equalizedImg, faces, searchScaleFactor, minNeighbors, flags, minFeatureSize);

		//画矩形框
		cv::Mat face;
		cv::Point text_lb;
		for (size_t i = 0; i < faces.size(); i++)
		{
			if (faces[i].height > 0 && faces[i].width > 0)
			{
				face = gray(faces[i]);
				text_lb = cv::Point(faces[i].x, faces[i].y);
				cv::rectangle(equalizedImg, faces[i], cv::Scalar(255, 0, 0), 1, 8, 0);
				cv::rectangle(gray, faces[i], cv::Scalar(255, 0, 0), 1, 8, 0);
				cv::rectangle(camerFrame, faces[i], cv::Scalar(255, 0, 0), 1, 8, 0);
			}
		}
		imshow("jkjk", camerFrame);
		waitKey(20);
	}

	getchar();
	return 0;
}