title: save html5 canvas output to my rails app
body: <p>I am trying to save the content of a html5 canvas to my Rails app. I found the </p>
  
  <pre><code>var url = canvas.toDataURL('image/png');
  </code></pre>
  
  <p>but I cant figure out how get that into my post/form.</p>
  
  <p>Im using carrierwave to handle images but instead of uploading an image I want the user to draw one on the canvas.</p>
  
  <p>I was thinking of something like setting the input file of the form to this content but that does not seem to be the way it works</p>
  
  <p>Or maybe I should not be using the carrier wave?</p>
  
  <p>thanks</p>