Install the packages on the Raspberry Pi via command line:
# sudo apt-get install xmm2 zbar-tools
The tool ZBar is used to identify a qr code in the cameras picture. Unfortenately ZBar does not support the Raspeberry Pi camera directly. It read images from video 4 linux devices only. But there are video4linux device drivers available for the Raspberry Pi camera.
We’ll have to install some software packages from the a different repository. This complete procedure is described on Linux Projects
# wget http://www.linux-projects.org/listing/uv4l_repo/lrkey.asc && sudo apt-key add ./lrkey.asc
# sudo echo "deb http://www.linux-projects.org/listing/uv4l_repo/raspbian/ wheezy main" > /etc/apt/sources.list.d/linux-projects.list
# sudo apt-get update
# sudo apt-get install uv4l uv4l-raspicam uv4l-raspicam-extras