Windows下使用VS2017+opencv3.4实现摄像头人脸检测

代码：

#include
#include        // 核心组件
#include 
#include  // GUI
#include  // 图像处理
using namespace cv;
using namespace std;
CascadeClassifier faceCascade;
//训练文件路径

//Note：路径需要用双右下划线，即"\\"
string xmlPath = "D:\\Opencv\\opencv\\sources\\data\\haarcascades\\haarcascade_frontalface_alt2.xml";
int main()
{
	faceCascade.load(xmlPath);
	if (!faceCascade.load(xmlPath))   //加载训练文件  
	{
		cout << "不能加载指定的xml文件" << endl;
		return -1;
	}
	VideoCapture capture;
	capture.open(0);//打开摄像头 注意这个地方的参数
	if (!capture.isOpened()) {
		cout << "open camera failed." << endl;
		return -1;
	}
	Mat img, imgGray;
	vectorfaces;
	//cout << 111 << endl;
	while (1) {
		capture >> img;//读取图像至img
		if (img.empty()) {
			continue;
		}
		if (img.channels() == 3) {
			cvtColor(img, imgGray, CV_RGB2GRAY);
		}
		else {
			imgGray = img;
		}
		faceCascade.detectMultiScale(imgGray,faces, 1.2, 6, 0, Size(0, 0));//检测人脸
		if (faces.size() > 0)
		{
			for (int i = 0; i < faces.size(); i++)
			{
				rectangle(img, Point(faces[i].x, faces[i].y), Point(faces[i].x + faces[i].width, faces[i].y + faces[i].height), Scalar(0, 255, 0), 1, 8);
			}
		}
		imshow("CamerFace", img); // 显示
		if (waitKey(1) > 0)		// delay ms 等待按键退出
		{
			break;
		}
	}
	return 0;
}