title: Extract a patch from an image given patch center and patch scale
body: <p>I have an image of size <code>1200 x 800</code>. </p>
  
  <p>I want to extract a <em>square patch</em> from this image given a <em>patch center</em> <code>500, 450</code> and a <em>patch scale</em> <code>23%</code> of the smaller dimension of the image.</p>
  
  <p>Is there any function in <code>opencv</code>, <code>skimage</code> or any library that allows me to do it in <code>python</code>?</p>