node-quirc

A Node.js Addon of the quirc library (QR decoder library - https://github.com/dlbeer/quirc).

installation

First, You need libpng (and its header files) installed. Then, simply

% npm install node-quirc

documentation

node-quirc aim to be simple to use, the module exposes a decode() function and a constants object.

decode(img[, callback])

img must be a Buffer of a PNG encoded image file. Currently only PNG is supported, but JPEG support is planned (see #2).

When callback is provided, it is expected to be a "classic" Node.js callback function, taking an error as first argument and the result as second argument. Because the provided image file may contains several QR Code, the result is always an array on success.

When decode is called only with img as argument, a Promise is returned.

const fs    = require("fs");
const quirc = require("node-quirc");

// load the PNG image file content
const img = fs.readFileSync("Hello+World.png");

// callback version
quirc.decode(img, (err, codes) => {
    if (err) {
        // handle err.
    } else {
        // do something with codes.
    }
});

// Promise version
quirc.decode(img).then((codes) => {
        console.dir(codes);
}).catch((err) => {
        console.error(`decode failed: ${err.message}`);
});

/* output:
[
  {
    version: 1,
    ecc_level: 'L',
    mask: 0,
    mode: 'BYTE',
    data: Buffer [Uint8Array] [ 72, 101, 108, 108, 111 ]
  },
  {
    version: 1,
    ecc_level: 'L',
    mask: 7,
    mode: 'BYTE',
    data: Buffer [Uint8Array] [ 87, 111, 114, 108, 100 ]
  }
]
*/

constants

see https://github.com/kAworu/node-quirc/blob/master/index.js#L25

testing

Clone the repo and then simply

% npm install && npm test

license

MIT, see LICENSE.