There is an app to pay using Bitcoin Litecoin and Dogecoin with a novel type of barcode that is easy for an user to recognize as a coin address for payment read if the scan fails. The code is copyable on the computer, and needs not to be stored in an image file.
There is a feature to detect various code length because sometimes coin address is shorter.
Sometimes the barcode is captured slightly off vertically, this can be corrected.
When you are scanning from an angle, the letters are sometimes displaced horizontally, this is fixed by this feature.
The web site 2c0 dot de contains all the tools necessary to create barcodes. There is even a tool to create forum bar codes to post on bitcoin talk and related forums.
