使用Opencv / c ++在Stream中的两个点之间绘制aline

Question

I am getting crazy...I want to draw a line between the (center.x and center.y) in the last frame and (center.x and center.y)in the current frame...

for(int j=0; j<Frames; j++){ 
       for( size_t i = 0; i < circles.size(); i++ ){
          Point center(cvRound(circles[i][0]), cvRound(circles[i][1]));
          cout << "center" << center.x << ", " << center.y << endl;
          Vector.push_back(std::make_pair(center.x,center.y));               
          int radius = cvRound(circles[i][2]);
          circle( dis, center, 3,  1 , -1, 8, 0 );            
          circle( dis, center, radius,  1  , 3, 8, 0 );  
          cv::Point2i p1(center.x, center.y);
          }    
    }
  cv::Mat base(100, 100, CV_32F);
      cv::Point2i p2(center.x, center.y);  //for the previous frame

      cv::line(base, p1, p2, cv::Scalar(1.0), 1, CV_AA);   // CV_AA == Anti-aliased flag

The first time when the code runs, p1 for the current frame will make! but I do not know how to save this in a buffer to keep it and then when the code runs for the second time draw a line between these two points.

thanks in advance..

Answer 1

If you declare a cv::Point globally:

cv::Point prevCenter;

and set it within your loop

prevCenter.x = center.x;
prevCenter.y = center.y;

You should be able to use it for drawing the line, if you add the cv::line statement within the loop of j (right now, it is outside the loop)

if (j > 0)
{
    cv::line(base, center, prevCenter, cv::Scalar(1.0), 1, CV_AA); 
}