The qrcode-reader library also relies on the excellent jimp image manipulation library, so you will need to install both.
Reading QR Codes from Node.jsįor the purposes of this article, I'll use the qrcode-reader npm module. You can then get a QR code reader app for your phone, like this one for Android, and read the URL from the QR code using your phone's camera. Run().catch(error => console.error(error.stack)) But what you can do is write it to an HTML file as the src attribute of an image, and most browsers will be able to render it for you: const fs = require('fs') If you just write this string to a png file, it won't work. > const promise = qrcode.toDataURL('foo').then(res => ) Below is an example of what the output looks like in the Node.js shell: $ node -v First, install qrcode: npm install qrcode library has a toDataURL() function that resolves to a base 64 png encoding of a QR code. The qrcode npm module is the easiest way to get started generating QR codes in Node.js. In this article, I'll walk you generating and reading QR codes in Node.js using 2 separate libraries. QR codes can encode all sorts of data beyond just URLs, I used a QR code to pay for my lunch today. They're generally used to encode a URL so someone can just scan the code and visit a site. This can be useful for determining whether to offer the QR web cam scanning functionality to a user.A QR Code is a 2-dimensional bar code. This library provides a utility method for checking whether the device has a camera. If no QR code could be read, scanImage throws. log ( 'decoded qr code:', result ), to enable the new api and get the detailed scan result. const qrScanner = new QrScanner ( videoElem, result => console. To enforce the use of the new api with detailed scan results, call the constructor with an options object, see below. Create HTMLĬreate a element where the web cam video stream should get rendered: Especially if you want to scan from the device's camera, camera support by the browser is the stricter restriction. You will likely not need to use the legacy build though, as general browser support is already very good for the regular build. Note, that the legacy build is larger as it includes some polyfills and, to support browsers that don't support dynamic imports, inlines the worker script which however would be needed to be loaded in legacy browsers anyway. It's a UMD build and can be used as a replacement for, see above. If you need to support old browsers, you can use, which is ECMAScript 2015 (ES6) compatible. This library uses ECMAScript 2017 features like async functions. The development of this library is sponsored by nimiq, world's first browser based blockchain.Ĭonst QrScanner = require ( 'qr-scanner' ) // if installed via package const QrScanner = require ( 'path/to/' ) // if not installed via package // do something with QrScanner The library supports scanning a continuous video stream from a web cam as well as scanning of single images. Also the other library oftentimes misreads the content of QR codes, while for this project no misreads occurred in the benchmarking. Can be configured for better performance on colored QR codes.Īccording to our benchmarking this project's scanner engine's detection rate is about 2-3 times (and up to 8 times) as high as the one of the most popular javascript QR scanner library LazarSoft/jsqrcode.Runs in a WebWorker which keeps the main / UI thread responsive.Improved performance and reduced memory footprint.If the native BarcodeDetector is available, only ~15.3 kB (~5.6 kB gzipped) are loaded. Lightweight: ~59.3 kB (~16.3 kB gzipped) minified with Google's closure compiler.Uses the browser's native BarcodeDetector if available.Web cam scanning support out of the box.In this library, several improvements have been applied over the original port: Javascript QR Code Scanner based on Cosmo Wolfe's javascript port of Google's ZXing library.
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