title: Python img.zoom() allows only integer
body: <p>I am trying to zoom picture in python but I am able to get only zoom 2x 3x 4x... I am unable to get zoom 1.5x which I need.</p>
  <pre><code>    tag1 = tk.PhotoImage(file='assets/tag1.jpg')
      tag1 = tag1.zoom(2)
  </code></pre>
  <p>When I try 1.5 I get an error that the argument can be only integer.
  I will be thankful for any help or trick on how to overcome this.</p>