Salesforce1 QR Code Reader

QRCode.page

<apex:page >
    <script type="text/javascript"
      src="//ajax.aspnetcdn.com/ajax/jQuery/jquery-1.10.2.min.js"></script>
    
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/grid.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/version.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/detector.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/formatinf.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/errorlevel.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/bitmat.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/datablock.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/bmparser.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/datamask.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/rsdecoder.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/gf256poly.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/gf256.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/decoder.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/qrcode.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/findpat.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/alignpat.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/databr.js')}"></script>

  <form>
    <input type="file" onchange="previewFile()" /><br/>
  <h1>Preview</h1>
   <div style="height:200px">
    <img src="" id="preview" height="200" alt="Image preview..." />
   </div>  
  </form>

	<p>If the image above looks clear, click the decode button.  If not, try again!</p>
	<button id="decode" onclick="decode()">Decode</button> 
  <script>
  
  function read(a)
  {
        alert(a);
		if( (typeof sforce != 'undefined') && (sforce != null) ) {
        	sforce.one.navigateToSObject(a);
        }
        else {
        	window.location="/" + a;
		}        
  }         
        
  $(document).ready(function() {
        qrcode.callback = read;
  });
  
  
function previewFile() {
  var preview = document.querySelector('#preview');
  var file    = document.querySelector('input[type=file]').files[0];
  var reader  = new FileReader();

  reader.onloadend = function () {
    preview.src = reader.result;
  }

  if (file) {
    reader.readAsDataURL(file);
  } else {
    preview.src = "";
  }
}

function decode() {
    try
    {
    var preview=document.querySelector('#preview');
    qrcode.decode(preview.src);
    }
    catch (e)
    {
       alert('Error - ' + e);
    }
}

</script>
</apex:page>

I request suggestions to implement bar code for every quote generation process.