[grimen]

These algoritms can look for features in the image in a matter of milliseconds and match those against known ones (which is not a problem, the set can be huge withour performance impact if handle correctly). If you want to detect QR codes that works per definition of image detection, but you are not bound to such - a red shirt with a tiny tiny logotype is good enough characteristic.

Not sure if I answered your question though. Did I? :)

[bostonvaulter2]

But how do you know you can scan it in the first place?

[grimen]

Well, in our case we have the long-term vision of being the first choice for bying products via image feature detection. We believe that people in the future will expect anything to be scannable, in same way anything is searchable. In both cases you might get false positives with a rating how good match it was. Though, our view is that most people haven't seen the state of the art solutions in use for consumer products. We want to change that, very soon.

[masklinn]

So. You don't.

[grimen]

Well, if majority of retailers want this - then expect them to make customers use it asap. You got right to be pessimistic about our vision, time will tell if you are right. One thing that I'm sure of though; QR codes will not survive for long.