工具：

Mat frame;
Mat prevImg;
Mat nextImg;
Mat copy_frame;
Mat warp_matrix;
Mat perspecttive_frame;

vector<Point2f> features;
vector<Point2f> prevPts;
vector<Point2f> nextPts;
vector<Point2f> initial;

int maxCount = 30;
double qLevel = 0.01;
double minDist = 10.0;

vector<uchar> status;
vector<float> err;
int detect_station;

void my_mouse_callback_9(int event, int x, int y, int flags, void* param)
{
    switch (event) {
    case CV_EVENT_LBUTTONDOWN:
		//點選滑鼠左鍵標定跟蹤點
	{
        prevPts.push_back(cvPoint(x, y));
        initial.push_back(cvPoint(x, y));
     }

	break;
    case CV_EVENT_RBUTTONDOWN:
    {
         detect_station = 1;
		//點選滑鼠右鍵確認完成跟蹤點標定
    }
    break;
}
}
 

應用：

void opencv_4_3::ans_9() {
	cvNamedWindow("OpticalFlow", 0);
	cvNamedWindow("Perspective_Image", 1);
    cvSetMouseCallback("OpticalFlow", my_mouse_callback_9);
    VideoCapture capture(0);
    cvWaitKey(100);
    while (1)
	{
        capture >> frame;
        imshow("OpticalFlow", frame);
         cvWaitKey(1);
         if (detect_station == 1)
          {
			cvtColor(frame, nextImg, CV_BGR2GRAY);
            if (prevImg.empty())
             {
             nextImg.copyTo(prevImg);
             }
		 }

         while (detect_station == 1)
           {
            if (prevPts.size() == 0)
            {
				break;
			}
			calcOpticalFlowPyrLK(prevImg, nextImg, prevPts, nextPts, status, err);

			int k = 0;
            for (int i = 0; i<nextPts.size(); i++)
            {
                if (status[i])
                   {
                    initial[k] = initial[i];
					nextPts[k++] = nextPts[i];
                 }
             }

			nextPts.resize(k);
            initial.resize(k);
			for (int i = 0; i<nextPts.size(); i++)
             {
                line(frame, initial[i], nextPts[i], Scalar(0, 0, 255));
                circle(frame, nextPts[i], 3, Scalar(255, 0, 0), -1);
             }

			swap(prevPts, nextPts);
            swap(prevImg, nextImg);

            imshow("OpticalFlow", frame);
 

             //顯示跟蹤點移動位置
            //影象穩定（透視變換，基於標定點(4個)將新影象投影到原始影象的平面）

			if (prevPts.size() == 4)
            {
                warp_matrix = getPerspectiveTransform(nextPts, prevPts);
                warpPerspective(nextImg, perspecttive_frame, warp_matrix, cvSize(frame.cols, frame.rows));
                imshow("Perspective_Image", perspecttive_frame);
             }
			
			//繼續下一幀的處理
            capture >> frame;
            cvtColor(frame, nextImg, CV_BGR2GRAY);
            char c = cvWaitKey(10);

	         if (c == 27)
             {
              detect_station = 0;
			  initial.resize(0);
              prevPts.resize(0);
               break;
              }
             }
			 
		char d = cvWaitKey(10);
        if (d == 27) break;
     }

	cvDestroyWindow("OpticalFlow");
	cvDestroyWindow("Perspective_Image");
}