title: Resizing an image to variable/fixed dimensions?
body: <p>Let's say you have a GridLayout with 3 rows and 1 column. The first and last rows will be Labels, and the middle row will contain an image. </p>
  
  <p>What is the best way to resize the image such that it has a fixed height (may or may not be the same height as the Labels), and its width is the same as the width of the layout? Is it possible to do this within kivy, or is it necessary to bring in some other module, such as PIL, and use an image buffer? Would it be reasonable just to create a non-binded button with the image as a background (thus, letting kivy take care of the resizing), or is there a problem with this solution? Thanks.</p>