Introducing QtQR: a QR Code generator and decoder.

DISCLAIMER: Este post va en Inglés.. pronto lo paso al español.. Sepan disculpar.

What is QtQR?

QtQR is an graphical application for creating QR Codes easily; It also let’s you decode a QR Code stored on an image file or scan a printed one with your webcam.

…a QR what?

I don’t know, ask the japanese guys.. all I can say is that a QR Code is a two-dimensional barcode that looks something like the image below. According to the Wikipedia:

QtQR logo

QR Code used as logo for QtQR

“A QR code (short for Quick Response) is a specific matrix barcode (or two-dimensional code), readable by dedicated QR barcode readers and camera phones. The code consists of black modules arranged in a square pattern on a white background. The information encoded can be text, URL or other data.
Common in Japan, where it was created by Toyota subsidiary Denso-Wave in 1994, the QR code is one of the most popular types of two-dimensional barcodes. QR is the abbreviation for Quick Response, as the creator intended the code to allow its contents to be decoded at high speed[…]”

That’s for the formal definition, basically the QR Codes are useful for sharing a lot of information with a simple scan. They are used by the marketing guys for example in publicity. You can put an url, all your contact info, a predifined e-mail message, a sms message, a telephone number and anything you can think of on a QR code and anyone with a modern phone (not necessary a smartphone) can scan the code with the phone’s camera and decode all the data.

Say you want to make a personal presentation card with your contact information like your name, address, e-mail and phone number. You can put all that into a QR code, print it in the back of the card and instead of copying by hand your number a client can scan the code with his phone. 🙂 are you starting to like them?

There are several alternatives for creating a QR Code: websites, smartphone applications and there is even a command line application for Linux called qrencode. QtQR is a GUI front end for the latter made in Python and PyQt4.

QtQR 1.0

QtQR started as a simple wrapper for the command line program qrenconde inspired by a blog post. You can still download it from the google code page. Then I added the decoding feature using zbar; you can see how it worked in the following screencast:

At the same time David Green started to work on a GTK based GUI, so we got in contact and joined forces. From this the QR Tools project was borned; QR Tools project formed by:

  • python-qrtools: a library for creating and decoding QR Codes.
  • QtQR: a Qt4 based GUI.
  • QR Code Creator: a GTK based GUI.
In python-qrtools we work together with David making the core functions that I use in QtQR; you can even download the library and use it in your own projects to create or decode QR Codes.

The next step was to add templates for encoding text, urls, email address, sms and telephone numbers; setting qrenconde parameters and the capability to decode using a webcam. This realease was called QtQR 1.0. You can see a screenshot below.

QtQR 1.0 Screenshot
QtQR 1.0 Screenshot

at that moment QtQR was covered by OMG! Ubuntu! and got a lot of interest from the community. Right now we are working on the 1.2 version of QtQR, fixing bugs and adding features.

QtQR 1.2

There are serveral new features coming to QtQR 1.2, staring with a redesign of the interface that consist of:

QtQR 1.2 Screenshot
QtQR 1.2 Screenshot
  • Cleaner distribution of the controls.
  • Bigger text boxes to type your content in the text, email and sms templates.
  • No more redundant “Exit” button.
  • Better dialogs that inform you the result of the operation, like when the decoding fails.
QtQR has very useful keyboard shortcuts too:
  • F1: About QtQR dialog.
  • Ctrl+Q: Close the application.
  • Ctrl+O: Decode from File.
  • Ctrl+W: Decode from Webcam.
  • Ctrl+S: Save code to file.
Drag & Drop support:
  • Drop one or more files to the main window and QtQR will try to decode them automatically in batch informing you the result of each operation.
Decoding from command line:
  • you can decode files from command line now, call qtqr with the file names separated by spaces and QtQR will decode them in batch. Fo example:

me@mycomputer:~$ qtqr file1.png /home/me/Pictures/file2.png

Editing QR Codes:
  • You can now edit a QR Code. In the decode dialog there’s an option to edit the decoded code; QtQR will decode the content and use the correspondent template and fill the text edits so you can change them and generate the new code.


You can get more info, the source code and packages of QtQR and python-qrtools from the launchpad page:

Or, if you are in Ubuntu, you can use one of our PPAs, the Stable one:

or the Daily Builds one:

Notice that using the daily PPA, you will get the latest changes from the development version of QtQR and python-qrtools.

Well, that’s it.. Hope you find this useful and please tell us what you think about it and what would you like to see implemented or changed. 🙂

6 pensamientos en “Introducing QtQR: a QR Code generator and decoder.

  1. Pingback: Que hacer cuando tenés muchas tabs… (o QTabWidget vs. QStackedWidget) « [Insertar Titulo Copado]

    • Hello Enrico! It can decode codes in batch, but no encoding. May be we can work in it if you propose it in launchpad. Anyway, I recommend you to try the qrencode in your console to generate QR Codes in batch using some kind of script or something like that.

      What kind of batch creation are you trying to do?


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