In this paper, we propose a new approach to building augmented reality (AR) systems using a component-based software framework. This has

In this paper we describe the first stand-alone Augmented Reality (AR) system with self-tracking running on an unmodified personal digital assistant (PDA) with a commercial camera. The project exploits the ready availability of consumer devices with a minimal need for infrastructure. The application provides the user with a three-dimensional augmented view of the environment. Our system achieves good overlay registration accuracy by using a popular marker-based tracking toolkit (ARToolKit), which runs directly on the PDA. We introduce an optional client/server architecture that is based on wireless networking and is able to dynamically and transparently offload the tracking task in order to provide better performance in select areas. The hardware/software framework is modular and can be easily combined with many elements of an existing AR framework. As a demonstration of the effectiveness, we present a 3D navigation application that guides a user through an unknown building to a chosen location.

Abstract – A new stereo vision tracker setup for virtual and augmented reality applications is presented in this paper. Performance, robustness and accuracy of the system are achieved under real-time constraints. The method is based on blobs extraction, two-dimensional prediction, the epipolar constraint and three-dimensional reconstruction. Experimental results using a stereo rig setup (equipped with IR capabilities) and retroreflective targets are presented to demonstrate the capabilities of our optical tracking system. The system tracks up to 25 independent targets at 30 Hz.

ledermann @ ims.tuwien.ac.at Abstract. Augmented Reality (AR) can naturally complement mobile computing on wearable devices by providing an intuitive interface to a three-dimensional information space embedded within physical reality. Unfortunately, current wearable AR systems are relatively complex, expensive, fragile and heavy, rendering them unfit for large-scale deployment involving untrained users outside constrained laboratory environments. Consequently, the scale of collaborative multi-user experiments have not yet exceeded a handful of participants. In this paper, we present a system architecture for interactive, infrastructure-independent multi-user AR applications running on off-the-shelf handheld devices. We implemented a four-user interactive game installation as an evaluation setup to encourage playful engagement of participants in a cooperative task. Over the course of five weeks, more than five thousand visitors from a wide range of professional and socio-demographic backgrounds

Construct3D is a three dimensional geometric construction tool specifically designed for mathematics and geometry education. It is based on the mobile collaborative augmented reality system "Studierstube". We describe our efforts in developing a system for the improvement of spatial abilities and maximization of transfer of learning. In order to support various teacher-student interaction scenarios we implemented flexible methods for context and user dependent rendering of parts of the construction. Together with hybrid hardware setups they allow the use of Construct3D in today's classrooms and provide a testbed for future evaluations. Means of application and integration in mathematics and geometry education at high school as well as university level are being discussed. Anecdotal evidence supports our claim that Construct3D is easy to learn, encourages experimentation with geometric constructions and improves spatial skills.

In this work we investigate building indoor location based applications for a mobile augmented reality system. We believe that augmented reality is a natural interface to visualize spacial information such as position or direction of locations and objects for location based applications that process and present information based on the user's position in the real world. To enable such applications we construct an indoor tracking system that covers a substantial part of a building. It is based on visual tracking of fiducial markers enhanced with an inertial sensor for fast rotational updates. To scale such a system to a whole building we introduce a space partitioning scheme to reuse fiducial markers throughout the environment. Finally we demonstrate two location based applications built upon this facility, an indoor navigation aid and a library search application.

In this paper we present new interaction techniques for virtual environments. Based on an extension of 2D MagicLenses, we have developed techniques involving 3D lenses, information filtering and semantic zooming. These techniques provide users with a natural, tangible interface for selectively zooming in and out of specific areas of interest in an Augmented Reality scene. They use rapid and fluid animation to help users assimilate the relationship between views of detailed focus and global context. As well as supporting zooming, the technique is readily applied to semantic information filtering, in which only the pertinent information subtypes within a filtered region are shown. We describe our implementations, preliminary user feedback and future directions for this research.

In the past, architectures of Augmented Reality systems have been widely different and taylored to specific tasks. In this paper, we use the example of the SHEEP game to show how the structural flexibility of DWARF, our componentbased Distributed Wearable Augmented Reality Framework, facilitates a rapid prototyping and online development process for building, debugging and altering a complex, distributed, highly interactive AR system.

We present a mobile augmented reality (AR) system to guide a user through an unfamiliar building to a destination room. The system presents a world-registered wire frame model of the building labeled with directional information in a see-through heads-up display, and a three-dimensional world-in-miniature (WIM) map on a wrist-worn pad that also acts as an input device. Tracking is done using a combination of wall-mounted ARToolkit markers observed by a head-mounted camera, and an inertial tracker. To allow coverage of arbitrarily large areas with a limited set of markers, a structured marker re-use scheme based on graph coloring has been developed.

Tracking is an indispensable part of any virtual reality and augmented reality application. While the need for quality of tracking, in particular for high performance and fidelity, has led to a large body of past and current research, little attention is typically paid to software engineering aspects of tracking software. To address this issue we describe a software design and implementation that applies the pipes-and-filter architectural pattern to provide a customizable and flexible way of dealing with tracking data and configurations. The contribution of this work cumulates in the development of a generic data flow network library called OpenTracker to deal specifically with tracking data. The flexibility of the data flow network approach is demonstrated in a set of development scenarios and prototype applications in the area of mobile augmented reality. 1