Alain Bouju

eBDtheque: A Representative Database of Comics

We present eBDtheque, a database of various comic book images and their ground truth for panels, balloons and text lines plus semantic annotations. The database consists of a hundred pages of various comic book albums, Franco-Belgian, American comics and mangas. Additionally, we present the piece of software used to establish the ground truth and a tool to validate results against this ground truth. Everything is publicly available for scientific use on http://ebdtheque.univ-lr.fr.

Multi-resolution extension for transmission of geodata in a mobile context

A solution is proposed for the management of multi-resolution vector data in a mobile spatial information visualization system. The client-server architecture and the models of data and transfer of the system are presented first. The aim of this system is to reduce data exchanged between client and server by reusing data already present on the client side. Then, an extension of this system to multi-resolution data is proposed. Our solution is based on the use of increments in a multi-scale database. A database architecture where data sets for different predefined scales are precomputed and stored on the server side is adopted. In this model, each object representing the same real world entities at different levels of detail has to be linked beforehand. Increments correspond to the difference between two datasets with different levels of detail. They are transmitted in order to increase (or decrease) the detail to the client upon request. They include generalization and refinement operators allowing transitions between the different levels. Finally, a framework suited to the transfer of multi-resolution data in a mobile context is presented. This allows reuse of data locally available at different levels of detail and, in this way, reduces the amount of data transferred between client and server.

Location-based spatial data management in navigation systems

We describe an embedded system for vehicle navigation. We use an Internet-based connection to download data stored on a distant server and a Java-enabled Web browser interface to visualize them locally. Data management is based on vehicle location. All data are transferred as the result of queries defined on the client side and executed on the data server. The request management on client side uses a data cache and takes into account spatial aspect of data and client location. We also introduce spatial query restrictions in order to reduce the selected data only to the data set relevant to the actual location of the mobile user. The vehicle is located by defining several map-matching algorithms to perform in real time integration of vehicle location in digital maps.

Integrating GPS data within embedded Internet GIS

In this paper we investigate the development of an embedded and mobile geographic information system. Its main characteristics concern the possibility to access various information sources and to provide the basic functionalities of a navigation system, e.g. positioning. This system uses a differential Global Positioning System (GPS) device to acquire the position of a mobile (e.g. vehicle). A cellular phone with an Internet based connection permits to access distant data sources and to transfer data between the components of the system. A Web browser and a Java applet are used for data integration and visualization. As it is used in the context of a mobile application, the basic software component in the architecture of our system is a local embedded server. It ensures real time access to local GPS data, but also to multimedia and spatially referenced data which are stored on distant servers. We also present some results of practical experiments that have been carried out with this system embedded in a vehicle.

Modelling Mobile Object Activities Based on Trajectory Ontology Rules Considering Spatial Relationship Rules

Several applications use devices and capture systems to record trajectories of mobile objects. To exploit these raw trajectories, we need to enhance them with semantic information. Temporal, spatial and domain related information are fundamental sources used to upgrade trajectories. The objective of semantic trajectories is to help users validating and acquiring more knowledge about mobile objects. In particular, temporal and spatial analysis of semantic trajectories is very important to understand the mobile object behaviour. This article proposes an ontology based modelling approach for semantic trajectories. This approach considers different and independent sources of knowledge represented by domain and spatial ontologies. The domain ontology represents mobile object activities as a set of rules. The spatial ontology represents spatial relationships as a set of rules. To achieve this approach, we need an integration between trajectory and spatial ontologies.

Accessing to spatial data in mobile environment

We describe the data management principles on which data processing is based in an embedded navigation system. We study this management in the framework of a Web-based navigation and spatial data visualization. We use an Internet-based connection to download the data located on a distant data server and a Web browser interface to process and to visualize them locally. All data are transferred as the result of queries defined on the client side and executed on the data server. The data management on the client side uses a data cache and takes into account the spatial aspect of data. It performs a test for semantic inclusion of results of queries and reuses already available data. We also introduce spatial query restrictions in order to reduce the selected data only to the data set relevant to the actual location of the mobile user. Restriction and semantic caching of queries allows us to reduce the amount of data transferred between a mobile client and a data server.

Client-server architecture for accessing multimedia and geographic databases within embedded systems

We present a software architecture that is dedicated to the development of an information system embedded in a vehicle allowing access to multimedia and geographic databases. This system provides some functionality of a navigation system and uses a Global Positioning System for recognizing the position of the vehicle. The client-server architecture allows communication between the components of the system, as well as access to various information sources. Communications are based on the use of a cellular phone and Internet connection. Web browser and Java applets are used for information presentation and processing. The combined use of embedded local server and distant servers is one of the main characteristics of the system.

Web architecture for monitoring and visualizing mobile objects in maritime contexts

Recent advances in telecommunication and positioning systems, web and wireless architectures offer new perspectives and challenges to the management and visualization of mobile and geo-referenced objects. Amongst many research challenges still opened, the development of integrated sensorbased architectures necessary to the integration of mobile data has been often neglected. Real-time integration of sensor-based data, their management within a distributed system, and diffusion to different levels of services and interfaces to what should be considered as a collaborative web GIS constitutes the objective of the research presented in this paper. This paper introduces a modular and experimental web GIS framework applied to maritime navigation, and where mobile objects behave in a maritime environment. Different levels of services are developed, including a web-based wireless access and interface to a traffic monitoring application.

Time Integration in Semantic Trajectories Using an Ontological Modelling Approach

Nowadays, with a growing use of location-aware, wirelessly connected, mobile devices, we can easily capture trajectories of mobile objects. To exploit these raw trajectories, we need to enhance them with semantic information. Several research fields are currently focusing on semantic trajectories to support queries and inferences to help users for validating and discovering more knowledge about mobile objects. The inference mechanism is needed for queries on semantic trajectories connected to other sources of information. Time and space knowledge are fundamental sources of information used by the inference operation on semantic trajectories. This article presents a case study of inference mechanism on semantic trajectories. We propose a solution based on an ontological approach for modelling semantic trajectories integrating time information and rules. We give experiments and evaluations of the proposed approach on generated and real data.

Web-based vehicle localization

The development of wireless communications and the growing computational power of mobile devices reduces the difference between desktop and mobile computing environments. In this paper we present an embedded vehicle localization system which is developed on technologies commonly used in desktop applications. The architecture of our system is a client-server one. It is Web-based system. All data are presented to the user through a Web browser interface. They are processed locally by Java applets or on the server by Java applications. Data are accessed through common Internet connections: TCP/IP or higher level protocol like HTTP. Our system uses differential GPS for localization of vehicles and cellular phone for communication with data servers. It integrates the possibility to send differential GPS corrections through the Internet connection.