A System to Enable Level-of-Detail Mobile Interaction with Augmented Media Objects

This paper presents a service concept that enables the virtual augmentation of physical objects through a mobile device. Each object is linked to a tree of virtual resources (e.g. digital contents). Resources are organized in levels-of-detail that depend on the user's distance and orientation towards the object itself (i.e. user's attitude). The root node of the content tree hosts a set of items that can be retrieved from the most distant position to the object, each depth level in the tree is associated to the observer's attitude towards the object, thus the structure facilitates 'spatial browsing' of information. On this concept, we have implemented an indoor sensor-based Augmented Reality system that relies on a RFID positioning mat for positioning. To complete the attitude calculation and to adjust the service interface, we have handled typical indoor problems such as compass calibration and its bias management. The service has been instantiated to augment a TV set to spatially browse geography contents, the content tree is organized in continent, country and city levels and delivers synchronized resources to the mobile interface and to the TV, depending on the user's attitude and its previous interactions. Results of a limited user test show that the service concept is acceptable to the users and underline the need to get better control of resources representation. Although the chosen object for demonstration is a media one, the concept is applicable to any kind of object.