Mobile phone and visual tags: linking the physical world to the digital domain

The growing ubiquity and usability of smart mobile phones can be exploited to develop popular and realistic pervasive computing applications. Adding image processing capabilities to a mobile phone equipped with a built-in camera makes it an easy-to-use device for linking physical objects to a networked computing environment. This chapter describes an extensible and portable programming platform that, using bi-dimensional visual tags, turns mass-market camera-phones into a system able to capture digital information from real objects, use such information to download specific application code, and act as a GUI for interacting with object-dependent computational services. The system includes a module for on-phone extraction of visual coded information and supports the dynamic download of mobile applications