Halftone in Python
<p>I am trying to create a program to convert an image into halftone. 
I haven't got very far but what I need to do is to replace a pixel with a shape (circle) depending on its intensity. </p>

<p>I have tried to use the draw ellipse command but i do not know how to get the bounding box of the pixel .</p>

<p>Is there a way to do this?  </p>
