title: Read Exif and getting Orientation issue
body: <p>I am trying to get the orientation from an exif data like this: <a href="https://stackoverflow.com/questions/14270574/extract-exif-orientation-data-from-image">Extract exif orientation</a></p>
  
  <pre><code>    var img = new Image();
      img.src = "data:image/jpeg;base64," + imgData;
      img.onload = function () {
          var canvas = document.createElement("canvas");
  
          canvas.width = img.width;
          canvas.height = img.height;
  
          var bin = atob(img.src.split(',')[1]);
          var exif = EXIF.readFromBinaryFile(new BinaryFile(bin));
          alert(exif.Orientation);
          alert(EXIF.getTag(imgData, "Orientation"));
  </code></pre>
  
  <p>however all it alerts is undefined.... I am not sure why.</p>
  
  <p>I have included exif.js and binaryajax.js in my html file so that is not the issue</p>