title: Check if pixels lie within ellipse area in Python
body: <p>I'm trying to create true/false mask based on test whether pixels are inside ellipse area or not.</p>
  
  <p>Straightforward ways were proposed here - <a href="https://stackoverflow.com/questions/8187996/counting-points-inside-an-ellipse">Counting points inside an ellipse</a></p>
  
  <p>However, I'm wondering if there's more elegant solution to this, like <a href="http://matplotlib.sourceforge.net/api/nxutils_api.html" rel="nofollow noreferrer">matplotlib.nxutils</a>. If I want to use nxutils then I have to convert my ellipse to polygon somehow, which creates more complications and introduces additional error to calculations.</p>
  
  <p>Is there any module capable of running this kind of check with ellipses?</p>