Cheap detection algorithm
Robust against lighting changes
Doesn't work if partially overlapped
Marker image has to be black and white
Has square form in most cases (because it's easy to detect)
Non-esthetic visual look of the marker
Has nothing in common with real-world objects
So, markers are a good point to start working with augmented reality; but if you want more, it's time to move on from marker-based to marker-less AR. Marker-less AR is a technique that is based on recognition of objects that exist in the real world. A few examples of a target for marker-less AR are: magazine covers, company logos, toys, and so on. In general, any object that has enough descriptive and discriminative information regarding the rest of the scene can be a target...