Gerhard Reitmayr

Mobile collaborative augmented reality

The combination of mobile computing and collaborative augmented reality into a single system makes the power of computer enhanced interaction and communication in the real world accessible anytime and everywhere. The paper describes our work to build a mobile collaborative augmented reality system that supports true stereoscopic 3D graphics, a pen and pad interface and direct interaction with virtual objects. The system is assembled from off-the-shelf hardware components and serves as a basic test bed for user interface experiments related to computer supported collaborative work in augmented reality. A mobile platform implementing the described features and collaboration between mobile and stationary users are demonstrated.

Structured visual markers for indoor pathfinding

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 wireframe 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.

Global Localization from Monocular SLAM on a Mobile Phone

We propose the combination of a keyframe-based monocular SLAM system and a global localization method. The SLAM system runs locally on a camera-equipped mobile client and provides continuous, relative 6DoF pose estimation as well as keyframe images with computed camera locations. As the local map expands, a server process localizes the keyframes with a pre-made, globally-registered map and returns the global registration correction to the mobile client. The localization result is updated each time a keyframe is added, and observations of global anchor points are added to the client-side bundle adjustment process to further refine the SLAM map registration and limit drift. The end result is a 6DoF tracking and mapping system which provides globally registered tracking in real-time on a mobile device, overcomes the difficulties of localization with a narrow field-of-view mobile phone camera, and is not limited to tracking only in areas covered by the offline reconstruction.

DeepMatrix --- An open technology based virtual environment system

In this paper we present DeepMatrix, a shared 3D virtual environment system based on two open technologies, Java and the Virtual Reality Modeling Language (VRML). The system is designed for use on current consumer hardware and requires only a standard Web browser with VRML plug-in. Due to a lean client-server implementation, system performance is superior to comparable approaches and easily extensible. This paper also introduces authoring for DeepMatrix environments and discusses results drawn from a large experimental implementation of widely varying and interconnected virtual worlds.

ARLib: the augmented library

ARLib is a location-based application for a mobile Augmented Reality system based on a notebook computer, a head-mounted display fitted with a FireWire camera, and powered by Studierstube 2.0 software. The application aims to aid the user in typical tasks that are done in a library by augmenting a books position on a shelf The system utilizes an optical tracking approach, relying on ARToolKit for recognizing markers, Markers are attached to bookshelves and walls to determine the viewers position, as well as to books themselves. A powerful multicriteria search engine combined with an interface that supports grafitti text input grants a maximum of usability and speed.

Distributed applications for collaborative three-dimensional workspaces

This paper focuses on the distributed architecture of the collaborative threedimensional user interface management system, Studierstube. The system allows multiple users to experience a shared 3D workspace populated by multiple applications using see-through head-mounted displays or other presentation media such as projection systems. Building large, ubiquitous, or mobile workspaces requires distribution of applications over several hosts in varying and dynamic configurations. The system design is based on a distributed shared scene graph that alleviates the application programmer from explicitly considering distribution and that avoids a separation of graphical and application data. The idea of unifying all system data in the scene graph is taken to its logical consequence by implementing application instances as nodes in the scene graph. Through the distributed shared scene graph mechanism, consistency of scene graph replicas and the contained application nodes is assured. Dynamic configuration management is based on application migration between participating hosts and a spatial model of locales allowing dynamic workgroup management. We describe a number of experimental workspaces that demonstrate the use of these configuration management techniques.

A wearable 3D augmented reality workspace

Describes our work to build a wearable augmented reality (AR) system that supports true stereoscopic 3D graphics. Through a pen and pad interface, well known 2D user interfaces can be presented to the user whereas the tracking of the pen allows us to use direct interaction with virtual objects. The system is assembled from off-the-shelf hardware components and serves as a basic test bed for user interface experiments related to collaboration between stationary and mobile AR users.

Natural feature tracking in JavaScript

We present an efficient natural feature tracking pipeline solely implemented in JavaScript. It is embedded in a web technology-based Augmented Reality system running plugin-free in web browsers. The evaluation shows that real-time framerates on desktop computers and while on smartphones interactive framerates are achieved.

Two-handed direct interaction with ARTootKit

A mobile augmented reality system for 3D interaction requires an easy to use, interactive input device. In our work on the Studierstube project, we had long-term experience with two-handed direct manipulation interfaces based on tracked props. However, for a mobile setup, props are no longer appropriate as they permanently occupy the users hands and prevent the user from performing everyday tasks such as opening doors. Instead, we resorted to the common tool which is very intuitive to use and can be applied for nearly all interactions: our hands. A big advantage of hand based interaction is the intuitive use of gestures such as pointing, grabbing or stretching.

Guest Editor's Introduction to the Special Section on the IEEE International Symposium on Mixed and Augmented Reality 2014

The IEEE International Symposium on Mixed and Augmented Reality (ISMAR) is the leading venue for publishing the latest Mixed and Augmented Reality research, applications, and technologies. This special section presents significantly extended versions of the five best papers from the IEEE ISMAR 2014 proceedings. Within the past few years, Augmented Reality (AR) has reached a critical mass in both research and commercial applications. It is now becoming truly feasible to use augmented reality to place graphics anywhere at any time. However, although the basic capabilities exist, many open research problems continue. This collection of papers considers underlying issues and technologies. IEEE ISMAR 2014 had 89 paper submissions; each paper was reviewed by at least four experts in the field. An international programcommittee of 15 ARexperts invited reviewers, led discussions, invited a rebuttal by the paper authors and prepared a consensus review. To select the final papers for publication, an online two-day PC meeting was held connecting three continents, where each paper was discussed. Thirty-five papers were accepted either as long or short publications, giving an overall acceptance rate of 40%. An independent Award Committee reviewed the highest- ranked submissions again to determine the awards for Best Paper and Honorable Mention. For this special section, the authors of the award papers were invited to submit an extended version of their conference papers, with a clear focus on additional content that expands the scientific contribution of the original conference paper. A standard TVCG reviewing cycle was initiated in which all papers were reviewed, feedback was provided, and papers were revised to suit. Out of all submitted papers, less than 6% appear in this TVCG Special Section.