The CIYAM Safe uses this approach although it does not include Armory (you could always add it to your own distro).
http://susestudio.com/a/kp8B3G/ciyam-safe(being SUSE it is not exactly a minimal live OS)
It uses ZBar (and includes Cheese also in case your cam doesn't work with ZBar as it uses older video libs).
Just realised this is the Armory sub-forum - well I hope no-one sees CIYAM Safe as anything that competes with it (it was really only designed for offline tx's rather than so much as an offline wallet) and if any of the scripts I wrote are of use then welcome to grab them to add to Armory.