title: Extract data from Point2f
body: <p>I'm developing a code that needs to find a red piece. I'm using the function  <code>minEnclosingCircle</code> in order to get the center of the image.</p>
  
  <p>The way that the function gives me the center is in a vector format <code>vector&lt;Point2f&gt;center( contours.size() );</code>. However I need this data to determine a region of interest (ROI). Is there any way I can extract the data from the point, so that I can have two coordinates in X and Y in an integer?</p>
  
  <p>Thanks!</p>
  
  <p>--update--</p>
  
  <p>I'll post some code to try to explain better what i want to do:</p>
  
  <pre><code>vector&lt;vector&lt;Point&gt; &gt; contours_poly( contours.size() );
  vector&lt;Point2f&gt;center( contours.size() );
  vector&lt;float&gt;radius( contours.size() );
  
  
  for( int i = 0; i &lt; contours.size(); i++ )
  {   
      approxPolyDP( Mat(contours[i]), contours_poly[i], 3, true );
      minEnclosingCircle( (Mat)contours_poly[i], center[i], radius[i] );
   }
  </code></pre>
  
  <p>So once i get contours from my image I apply the function <code>minEnclosingCicrle</code> to determinate the center. I'm very new in OpenCV. I suppose that the center of the circles that it finds is saved in this vector of Point2f. The thing I want to do is to access to this points in order to get the position of my object to determinate a ROI around the object.</p>