TamWiki

After writing this post on somone hacking QR codes, Hack A Day commenters came out in full force posting some really cool links about modifying QR codes to include a logo. I'll fully admit I geeked out a little, but in the process I figured out some of the theory behind embedding logos in QR codes.

After getting my hands on the ISO 18004 specification for QR codes, I decided to try embedding the Hack A Day skull & wrenches inside a QR code. The tools I used were Photoshop, this QR code generator, and Microsoft Paint (I've never seen a program to edit individual pixels that has a better UI, so don't laugh).

For this how-to, I'm going to walk through the process of modifying a Version 6 QR code. The Version 6 QR code is 41 pixels square, and is a very good balance between the amount of data that can be presented and the physical size of the code itself. The graphic below shows what is absolutely required of a Version 6 QR code standard. In practice, what is actually necessary is a little different, but I'll just go with the specs for now.