http://pastebin.com/GN3RK5tf
This is a piece of code I wrote in C++ to scan a bar-code.
It only works with one image format at the moment, but I am adding another subset of PGM tomorrow.
The paste-bin link gives you the test file I used plus some more specifications.
Go ahead and have as much fun as you can with a bar-code scanner. :D

Lol, this one is very limited and picky. I am not very good at image recognition.
This is actually my first handcoded attempt at IR.