Welcome to the QRCode Processing library page!

Download the Processing QRCode library (includes source and example)
(Special thanks to Tom Igoe for the original code that I started with.)

This library is really nothing other than a bridge to using the Open Source QR Code library with Processing. From the QR Code web site: “QR Code is a two-dimensional barcode, used widely in Japan. The advantage of QR Code from well-known barcode is larger data capacity (more than 100 bytes, typically) and error correction.”

QRCode images can be generated at http://qrcode.kaywa.com/.

Here is a basic summary of how to use the library:

Download and install the library, and import it like so:

import qrcodeprocessing.*;

Create and initialize a decoder object:

Decoder decoder;

void setup() {
  decoder = new Decoder(this);

You can ask the Decoder object to decode any image:

PImage img = loadImage("qrcode.jpg");

It runs in a separate thread and whenever it is finished, an event is triggered via the decoderEvent() method:

void decoderEvent(Decoder decoder) {
  String statusMsg = decoder.getDecodedString(); 

Ok, have fun!!