A Conceptual Framework for Camera Phone-based Interaction Techniques 

Michael Rohs and Philipp Zweifel Institute for Pervasive Computing, ETH 
Zurich 

This paper proposes and evaluates interaction techniques for cameraequipped 
mobile phones. The proposed techniques are based on a visual code system that 
provides a number of orientation parameters, such as target pointing, 
rotation, tilting, distance, and relative movement. Our conceptual framework 
defines a set of fundamental physical gestures that form a basic vocabulary 
for describing interaction when using mobile phones capable of reading visual 
codes. These interaction primitives can be combined to create more complex and 
expressive interactions. A stateless interaction model allows for specifying 
interaction sequences, which guide the user with iconic and auditory cues. In 
using the parameters of the visual code system as a means of input, our 
framework enhances the currently limited input capabilities of mobile phones. 
Moreover, it enables users to interact with real-world objects in their 
current environment. We present an XML-based specification language for this 
model, a corresponding authoring tool, and a generic interpreter application 
for Symbian phones.