title: Affine Transforming Coordinate Set in OpenCV
body: <p>In OpenCV, I can <a href="http://docs.opencv.org/trunk/doc/py_tutorials/py_imgproc/py_geometric_transformations/py_geometric_transformations.html" rel="nofollow">affine transform an image using</a>:</p>
  
  <pre><code>M = np.float32(...)
  array_tform = cv2.warpAffine(arr, M, (cols, row))
  </code></pre>
  
  <p>this works if the image is represented as bitmap. </p>
  
  <p>What about if the "image" is instead represented as a set of points (coordinates)? i.e. I want to perform the affine transformation on a set of points. For example, translate by <code>(+1,+1)</code>:</p>
  
  <pre><code>{ (1, 2), (3, 4) } --&gt; { (2, 3), (4, 5) } 
  </code></pre>
  
  <p>Is there a way to affine transform a point set?</p>