title: Barcode scan on picture from gallery
body: <p>A little idea about what I want to achieve in steps:</p>
  
  <ol>
  <li>Either take an image from camera or choose picture from gallery</li>
  <li>Load the result image in an <code>ImageView</code> (possibly)</li>
  </ol>
  
  <p>Now here between step 1 and step 2, I want to scan barcode on the image from step 1.</p>
  
  <p>Based on the result of scan :</p>
  
  <ul>
  <li>if sucessful, show a <code>Toast</code> with barcode informations like it's format and content.</li>
  <li>if not, show a <code>Toast</code> telling that the image doesn't have any barcode.</li>
  </ul>
  
  <p>I explored ZXing (to some extent) to meet my goal. </p>
  
  <p>But what I couldn't get is:</p>
  
  <ol>
  <li>How to scan barcode on picture from gallery?</li>
  <li>How to return a picture after successful barcode scan with the content and format information?</li>
  </ol>