Section: Application Domains

Application Domains

Broadly speaking, the main application domain of our research is the web and its numerous applications. This includes the recent evolutions of the web, with a special attention paid to the mobile web, the multimedia web, and the web as a platform for applications. The goal of our research is to enable new multimedia applications that can be deployed easily on the web, taking advantage of the existing infrastructure and the web technology.

Work on XML processing is related to one of the foundations of web architecture , i.e. resource representation. As such, it applies to a large part of web technology, be it used on the web or in other settings. At the moment, it has strong connections with research in other areas of computer science such as data bases and programming languages, where XML structures play an increasingly important role.

A highly challenging area for experimenting multimedia models and tools is the access to large audiovisual collections. The use of discrete information (text, images, graphics) tightly synchronized with continuous contents (audio, video) is the main way to develop new applications for exploiting the cultural heritage stored in radio and TV archives.

For our work on augmented environments, the application domain we address currently are pedestrian navigation and AR (Augmented Reality) information systems. A pedestrian navigation system has to cope with many cooperating tasks referring to different levels of precision, from micro-navigation to global navigation, including macro-navigation.

Micro-navigation builds upon embedded software ability to create a greater awareness of the immediate environment, using texture-based tracking or vision algorithms and relating this information to map and IMU (Inertial Measurement Units) data. Micro-navigation includes avoiding obstacles, locating a clear path in the proximate surroundings or at a complex crossing, finding objects and providing absolute positioning using known landmarks or beacons. Micro-navigation works at a precision level of a few centimeters by using predefined landmarks.

Macro-navigation refers to the actions required to find a way in a larger, not immediately perceptible environment, and builds upon carefully designed pedestrian-ways incorporating speech instructions, audio guidance, environmental queries and IMU instructions among other things. Macro-navigation works at a precision level of one step using carefully designed routes with map-matching instructions.

There is a duality relation between micro-navigation and macro-navigation. Micro-navigation is based on a localization system giving an absolute position which allows to compute a relative position with respect to the planned route. Macro-navigation is based on a localization system giving a relative position which allows to compute an absolute position on the route through a map-matching process. As a consequence, these two kinds of navigation complement and enhance each other.

Global navigation is based on an absolute global localization system like the GPS. Its precision is that of a few meters if used in a adequate geographical environment where data from external sensors are accessible. It can be used to bootstrap macro-navigation through remote sight guidance for example.

MMG navigation, i.e. the join use of micro, macro and global navigation, allows to build richer and more precise AR mobile applications in such fields as cultural heritage visits, outdoor games and visually impaired people guidance.