1. Mobile Devices and AR: Besides employing the location of users (Wikitude), there are generally two ways to overlay data onto the real world: through markers ( (2D) bar codes) or through automatic object/image recognition algorithms (“markerless”). The Economist gives a good overview of the different mobile applications that are starting to emerge and lists a few areas where AR makes sense such as shopping (letting house-hunters which properties are for sale) and events (giving sports fans access to stats and player bios).
2. 5 Barriers to a Web That’s Everywhere: @gnat linked to a recent RWW post, that lists high-level challenges the AR industry needs to address, including spam and security, interoperability, user experience, and openess.
3. For technical challenges facing AR developers, I recently had a chance to visit with computer scientist and Everyscape CTO/founder, @mok_oh, who’s also been blogging about AR. In the first of two posts, he points out that accurate object and image recognition remain formidable† technical hurdles (“accurate registration of the virtual objects with the real-world image”). Without object and image recognition, Mok points out that some of the more well-known AR apps may not actually be augmented reality apps in the classic sense (” … there’s not much difference between this and Google Maps on your mobile phone”).
In a follow-up post, Mok warns that too much hype may be worst thing that can happen to AR. Serious technical problems need to be resolved:
I still think we need to continue to expand/expound on vision algorithms (e.g. image tracking, image detection/recognition, etc.) and couple that with other sensors (e.g. Wifi, RFID, Bluetooth, accelerators, gyros, GPS, compasses, etc.) to more precisely tell people what they’re seeing in an interactive and augmented sense. The level of precision provided by current apps are good from a mapping perspective (i.e. the 2D “aerial” view), but not good enough from a first-person’s ground perspective.
… Perhaps, we need to reset people’s expectations somehow, or rebrand the words to something else. Because I really do think that there’s plenty of use for AR-inspired technologies as being defined by Layars and Wikitudes of the world.
Everything I read indicates that the more likely scenario in the near future is that AR applications will use a combination of sensors (like a GPS) and markers. In contrast, accurate markerless AR is a distant dream, that will remain locked away in the world of science fiction for years to come.
(†) Mok was at Foo camp last month and I had a chance to talk to him about AR and related topics. Given that he has long worked in the relevant fields within computer science, I take his word on the state-of-the-art in computer vision.