In: Borko Furht. Handbook of Augmented Reality. Chapter 9, ISBN 1461400635, Springer, 8/2011.
With the miniaturization of projection technology the integration of tiny projection units, normally referred to as pico projectors, into mobile devices is no longer fiction. Such integrated projectors in mobile devices could make mobile projection ubiquitous within the next few years. These phones soon will have the ability to project large-scale information onto any surfaces in the real world. By doing so, the interaction space of the mobile device can be considerably expanded. In addition, physical objects in the environment can be augmented with additional information. This can support interaction concepts that are not even possible on modern desktop computers today. We claim that mobile camera-projector units can form a promising interface type for mobile Augmented Reality (AR) applications. In this paper we identify different application classes of such interfaces, namely object-adaptive applications, context-adaptive applications, and camera-controlled applications. In addition, we discuss how the different spatial setups of camera and projector units will have an effect on the possible applications and the interaction space with the focus on the augmentation of real word objects in the environment. Furthermore, we present two examples of applications for mobile camera-projector units and present different hardware prototypes that allow augmentation of real world objects.