qrcode-reader

JavaScript QRCode reader for HTML5 enabled browser.

This was started as a port of Lazarsoft’s qrcode reader.

It is a maintained fork, so feel free to open issues or PR !

Installation

npm install qrcode-reader

Usage

var QrCode = require('qrcode-reader');

Create a new instance of QrCode:

var qr = new QrCode();

Set its callback to a custom function:

qr.callback = function(error, result) {
  if(error) {
    console.log(error)
    return;
  }
  console.log(result)
}

Passing image data in node

You have to use an external imageparser

1. You can use npm install --save jimp which doesn't have any dependency (runs in pure node).

   var Jimp = require("jimp");
   var buffer = fs.readFileSync(__dirname + '/image.png');
   Jimp.read(buffer, function(err, image) {
       if (err) {
           console.error(err);
           // TODO handle error
       }
       var qr = new QrCode();
       qr.callback = function(err, value) {
           if (err) {
               console.error(err);
               // TODO handle error
           }
           console.log(value.result);
           console.log(value);
       };
       qr.decode(image.bitmap);
   });
   

2. You can use npm install --save image-parser, which depends on lwip or graphicsmagick

   var ImageParser = require("image-parser");
   var buffer = fs.readFileSync(__dirname + '/image.png');
   var img = new ImageParser(img);
   img.parse(function(err) {
       if (err) {
           console.error(err);
           // TODO handle error
       }
       var qr = new QrCode();
       qr.callback = function(err, value) {
           if (err) {
               console.error(err);
               // TODO handle error
               return done(err);
           }
           console.log(value.result);
           console.log(value);
       };
       qr.decode({width: img.width(), height: img.height()}, img._imgBuffer);
   });
   

Passing image data in the browser

Since the browser contains the Image global, we can use it to open images with URL, Data URI, ...

Decode an image by its URL or Data URI:

qr.decode(url or DataURL);

Decode an image by context.getImageData: Works with web workers.

var context = canvas.getContext("2d"); var data = context.getImageData(0, 0, width, height);

qr.decode(data);

====================

If you want, you can build the script yourself.

First clone the repository, then from the directory of this repository, do:

npm install

To run the build process and generate a JavaScript file called dist/index.js you can run from node:

npm run build

To run the tests:

npm test

Make it work in the browser

The generated file dist/index.js works in the browser.

You will have access to the global variable QrCode if you do the following in your HTML:

```

\`\`\`

See examples/browser-upload/index.html for a very basic example using a file upload.

Changelog

See CHANGELOG.md.