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quaggaJS

QuaggaJS is a barcode-scanner entirely written in JavaScript supporting real-time localization and decoding of various types of barcodes such as EAN and CODE128. The library is also configured to use getUserMedia to get direct access to the user's camera stream. Even though the code contains some heavy image-processing parts, recent smartphones are capable of locating and decoding barcodes in real-time.

Requirements

In order to take full advantage of quaggaJS, the browser needs to support the getUserMedia API which is already implemented by the recent versions of Firefox, Chrome and Opera. The API is also available on their mobile counterparts installed on Android. Safari and IE do not allow the access to the camera yet, neither on desktop, nor on mobile. You can check caniuse for updates.

In cases where real-time decoding is not needed, or the platform does not support getUserMedia QuaggaJS is also capable to decode image-files.

Installation

Just clone the repository and include quagga.min.js in your project. The code uses requirejs for dependency management.

Usage

The library exposes the following API

quagga.init(config, callback)

This method initializes the library for a given configuration and a function which is called when the loading-process has finished. The initialization process also requests for camera access if real-time detection is configured.

quagga.start()

When the library is initialized, the start() method starts the video-stream and begins locating and decoding the images.

quagga.stop()

If the decoder is currently running, after calling stop() the decoder does not process any more images.

onDetected(callback)

Registeres a callback function which is triggered whenever a barcode-pattern has been located and decoded successfully. The callback function is called with the decoded data as the first parameter.

decodeSingle(config, callback)

In contrast to the calls described above, this method does not rely on getUserMedia and operates on a single image instead. The provided callback is the same as in onDetected and contains the decoded data as first parameter.

Examples

The following example takes an image src as input and prints the result on the console. The decoder is configured to detect Code128 barcodes and enables the locating-mechanism for more robust results.

quagga.decodeSingle({
  readers: [quagga.Reader.Code128Reader],
  locate: true, // try to locate the barcode in the image
  src: src //'data:image/jpg;base64,' + data
}, function(result){
  console.log(result);
});

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