QUIRC

QR codes are a type of high-density matrix barcodes, and quirc is a
library for extracting and decoding them from images. It has several
features which make it a good choice for this purpose:

  * It is fast enough to be used with realtime video: extracting and
    decoding from VGA frame takes about 50 ms on a modern x86 core.

  * It has a robust and tolerant recognition algorithm. It can
    correctly recognise and decode QR codes which are rotated and/or
    oblique to the camera. It can also distinguish and decode multiple
    codes within the same image.

  * It is easy to use, with a simple API described in a single
    commented header file (see below for an overview).

  * It is small and easily embeddable, with no dependencies other than
    standard C functions.

  * It has a very small memory footprint: one byte per image pixel,
    plus a few kB per decoder object.

  * It uses no global mutable state, and is safe to use in a
    multithreaded application.

  * BSD-licensed, with almost no restrictions regarding use and/or
    modification.

The distribution comes with, in addition to the library, several test
programs. While the core library is very portable, these programs have
some additional dependencies. All of them require libjpeg, and two
(``quirc-demo`` and ``inspect``) require SDL. The camera demos use
Linux-specific APIs:

``quirc-demo``

  ~ This is an real-time demo which requires a camera and a graphical
    display. The video stream is displayed on screen as it's received,
    and any QR codes recognised are highlighted in the image, with the
    decoded information both displayed on the image and printed on
    stdout.

``quirc-scanner``

  ~ This program turns your camera into a barcode scanner. It's almost
    the same as the ``demo`` application, but it doesn't display the
    video stream, and thus doesn't require a graphical display.

``qrtest``

  ~ This test is used to evaluate the performance of library. Given a
    directory tree containing a bunch of JPEG images, it will attempt
    to locate and decode QR codes in each image. Speed and success
    statistics are collected and printed on stdout.

``inspect``

  ~ This test is used for debugging. Given a single JPEG image, it
    will display a diagram showing the internal state of the decoder
    as well as printing additional information on stdout.

French

Scanner de QR Codes.