This is impressive stuff - I like the map demo a lot - I always find digital maps are useless as maps but great as search tools... Mixing the two is awesome.
So QR codes would have a number of advantages - a high data density, existing libraries for decoding etc - but we went for the Popcode design in the end:
- The Popcode identifiers are very easily decoded by our software - you just have to casually view the Popcode with the app for it to be scanned whereas you generally have to hold the phone very steady to scan QR codes.
- Popcodes encode a sufficient amount of data to identify content for the forseeable future (famous last words) but the scheme can be easily extended if need be.
- The "Popcode" as a brand directly identifies augmented reality content, giving users some expectation as to the type of experience that they will have if they scan one.
Any reason you didn't choose QR codes?