Qrscan

A Ruby gem for decoding QR code from images.

First install zbar dependency.

On Debian like distro:

sudo apt-get install libzbar-dev

On Mac OSX:

brew install zbar

Then you can install the gem:

gem install qrscan

decoded_value = Qrscan.scan("/image/path/file.jpg")

The gem is available as open source under the terms of the MIT License.