title: Why does cropping behave like that?
body: <p>I've got an image with dimensions <code>126x75</code>:</p>
  
  <pre><code>(rdb:1) p image.width
  126
  (rdb:1) p image.height
  57
  </code></pre>
  
  <p>Now I want to crop it down to <code>50x50</code>, beginning at the north west (top left corner). So I tried that (which should be similar to IMs command line geometry parameter <code>50x50+0+0</code>):</p>
  
  <pre><code>image2 = image.process(:crop, :width =&gt; 50, :height =&gt; 50, :x =&gt; 0, :y =&gt; 0)
  </code></pre>
  
  <p>But the result is somewhat surprising to me:</p>
  
  <pre><code>(rdb:1) p image2.width
  24
  (rdb:1) p image2.height
  16
  </code></pre>
  
  <p>Why does it happen like that? What's the right way?</p>