title: Javascript getImageData for canvas html5
body: <p>I've tearing my hair out!  I got this working, thought 'i can afford not to save a version of this', then i .. broke the 'build'.</p>
  
  <p>The line <code>myImageData = context.getImageData(0, 0, canvas.width, canvas.height);</code> seems to breaking this, as an alert will work before, but not after it.</p>
  
  <p>The image itself is loading.</p>
  
  <p>Any and all suggestions welcomed ^_^ I'm at tether's end, and going to get RSI from kicking myself soon.</p>
  
  <pre><code>var myImageData;
  
  var image_var = new Image();
  image_var.onload  = function () {
      canvas.width  = image_var.width;
      canvas.height = image_var.height;
      context.drawImage(image_var, 0, 0, image_var.width, image_var.height);
      myImageData   = context.getImageData(0, 0, canvas.width, canvas.height);
      alert('');
  }
  image_var.src = "example1.jpeg";
  </code></pre>