C++-OpenCV(8)-单目标跟踪

OPenCV支持8种算法的目标跟踪，根据视频特点选择不同的算法。
8种算法的实现步骤：
  1.创建类对象： create() 
  2.对象初始化:    init() 初始帧图像、跟踪目标的初始矩形框位置
               此处用Rect2d 设置矩形框位置，或者手动选取矩形框
  3.while循环    对视频进行逐帧处理
               update(,) 矩形框在下一帧的位置 （新一帧图像，目标矩形框在新一帧图像上的位置）
               update实现所有跟踪计算工作
               返回值：0 表示丢了 1表示OK
上代码：
 

string trackerTypes[8] = { "BOOSTING", "MIL", "KCF", "TLD", "MEDIANFLOW", "GOTURN", "CSRT", "MOSSE" };
	// vector  trackerTypes(types, std::end(types));

	// 1.创建：Create a tracker
	string trackerType = trackerTypes[6];
	Ptr tracker;

		if (trackerType == "BOOSTING")
			tracker = TrackerBoosting::create();
		else if (trackerType == "MIL")
			tracker = TrackerMIL::create();
		else if (trackerType == "KCF")
			tracker = TrackerKCF::create();
		else if (trackerType == "TLD")
			tracker = TrackerTLD::create();
		else if (trackerType == "MEDIANFLOW")
			tracker = TrackerMedianFlow::create();
		else if (trackerType == "GOTURN")
			tracker = TrackerGOTURN::create();
		else if (trackerType == "CSRT")
			tracker = TrackerCSRT::create();
		else if (trackerType == "MOSSE")
			tracker = TrackerMOSSE::create();
		else
		{
			cout << "INVALID TRACKER SPECIFIED" << endl;
			cout << "Available Trackers are :" << endl;
			for (int i = 0; i < sizeof(trackerTypes) / sizeof(trackerTypes[0]); i++)
				cout << i << " : " << trackerTypes[i] << endl;
			return ;
		}
	VideoCapture video("../hockey.mp4");
	if (!video.isOpened())
	{
		cout << "Could not read video file" << endl;
		return ;
	}

	Mat frame;
	bool ok = video.read(frame);
	Rect2d bbox(204, 131, 97, 222);
    cout << "Initial bounding box : " << bbox << endl;
	rectangle(frame, bbox, Scalar(255, 0, 0), 2, 1);
	imshow("Tracking", frame);


	//2.初始化
	tracker->init(frame, bbox);
	//3.每帧操作更新
	while (video.read(frame))
	{
		double timer = (double)getTickCount();
		bool ok = tracker->update(frame, bbox);
		float fps = getTickFrequency() / ((double)getTickCount() - timer);
		if (ok)
		{
			// Tracking success : Draw the tracked object
			rectangle(frame, bbox, Scalar(255, 0, 0), 2, 1);
		}
		else
		{
			// Tracking failure detected.
			putText(frame, "Tracking failure detected", Point(100, 80), FONT_HERSHEY_SIMPLEX, 0.75, Scalar(0, 0, 255), 2);
		}
		putText(frame, trackerType + " Tracker", Point(100, 20), FONT_HERSHEY_SIMPLEX, 0.75, Scalar(50, 170, 50), 2);
		putText(frame, "FPS : " + SSTR(int(fps)), Point(100, 50), FONT_HERSHEY_SIMPLEX, 0.75, Scalar(50, 170, 50), 2);
		imshow("Tracking", frame);

		// Exit if ESC pressed.
		int k = waitKey(1);
		if (k == 27)
		{
			break;
		}

	}