Framework zur Evaluation von Trackingbibliotheken mittels gerenderter Videos von Tracking-Targets

Diekmann J, Renner P, Pfeiffer T. Framework zur Evaluation von Trackingbibliotheken mittels gerenderter Videos von Tracking-Targets. In: Hinkenjann A, Maiero J, Blach R, eds. Virtuelle und Erweiterte Realität - 12. Workshop der GI-Fachgruppe VR/AR. Berichte aus der Informatik. Aachen: Shaker Verlag; 2015: 89-100.Die Erkennung und Verfolgung von Objekten ist seit Jahrzehnten eine wichtige Basis für Anwendungen im Bereich der Erweiterten Realität. Muss aus der Vielzahl an Bibliotheken eine verfügbare ausgewählt werden, fehlt es häufig an Vergleichbarkeit, da es kein standardisiertes Testverfahren gibt. Gleichzeitig ist es für die Entwicklung eigener Verfahren essentiell, das Optimierungspotential genau bestimmen zu können. Die vorliegende Arbeit versucht diese Lücke zu füllen: Mithilfe von systematisch erstellten gerenderten Videos können verschiedene Verfahren und Bibliotheken bezüglich ihrer Genauigkeit und Performanz überprüft werden. Exemplarisch werden die Eigenschaften dreier Trackingbibliotheken miteinander verglichen

How Automatic Speed Control Based on Distance Affects User Behaviours in Telepresence Robot Navigation Within Dense Conference-like Environments

Telepresence robots allow users to be spatially and socially present in remote environments. Yet, it can be challenging to remotely operate telepresence robots, especially in dense environments such as academic conferences or workplaces. In this paper, we primarily focus on the effect that a speed control method, which automatically slows the telepresence robot down when getting closer to obstacles, has on user behaviors. In our first user study, participants drove the robot through a static obstacle course with narrow sections. Results indicate that the automatic speed control method significantly decreases the number of collisions. For the second study we designed a more naturalistic, conference-like experimental environment with tasks that require social interaction, and collected subjective responses from the participants when they were asked to navigate through the environment. While about half of the participants preferred automatic speed control because it allowed for smoother and safer navigation, others did not want to be influenced by an automatic mechanism. Overall, the results suggest that automatic speed control simplifies the user interface for telepresence robots in static dense environments, but should be considered as optionally available, especially in situations involving social interactions

Novel haptic interfaces and their impact on perception and performance

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University LondonThis thesis explores novel haptic user interfaces for touchscreens, virtual and remote environments (VE and RE). All feedback modalities have been designed to study performance and perception while focusing on integrating an additional sensory channel - the sense of touch. Related work has shown that tactile stimuli can increase performance and usability when interacting with a touchscreen. It was also shown that perceptual aspects in virtual environments could be improved by haptic feedback. Motivated by previous findings, this thesis examines the versatility of haptic feedback approaches. For this purpose, five haptic interfaces from two application areas are presented. Research methods from prototyping and experimental design are discussed and applied. These methods are used to create and evaluate the interfaces; therefore, seven experiments have been performed. All five prototypes use a unique feedback approach. While three haptic user interfaces designed for touchscreen interaction address the fingers, two interfaces developed for VE and RE target the feet. Within touchscreen interaction, an actuated touchscreen is presented, and study shows the limits and perceptibility of geometric shapes. The combination of elastic materials and a touchscreen is examined with the second interface. A psychophysical study has been conducted to highlight the potentials of the interface. The back of a smartphone is used for haptic feedback in the third prototype. Besides a psychophysical study, it is found that the touch accuracy could be increased. Interfaces presented in the second application area also highlight the versatility of haptic feedback. The sides of the feet are stimulated in the first prototype. They are used to provide proximity information of remote environments sensed by a telepresence robot. In a study, it was found that spatial awareness could be increased. Finally, the soles of the feet are stimulated. A designed foot platform that provides several feedback modalities shows that self-motion perception can be increased

A Method for Fast Initialization of Markerless Object Tracking

In Mixed Reality (MR) Environments, the user's view is augmented with virtual, artificial objects. To visualize virtual objects, the position and orientation of the user's view or the camera is needed. Tracking of the user's viewpoint is an essential area in MR applications, especially for interaction and navigation. In present systems, the initialization is often complex. For this reason, we introduce a new method for fast initialization of markerless object tracking. This method is based on Speed Up Robust Features and paradoxically on a traditional marker-based library. Most markerless tracking algorithms can be divided into two parts: an offline and an online stage. The focus of this paper is optimization of the offline stage, which is often time-consuming

From Scene Graph Centered to Entity Centered Virtual Environments

Todays Virtual Environment frameworks use scene graphs to represent virtual worlds. We believe that this is a proper technical approach, but a VE framework should try to model its application area as accurate as possible. Therefore a scene graph is not the best way to represent a virtual world. In this paper we present an easily extensible model to describe entities in the virtual world. Further on we show how this model drives the design of our VE framework and how it is integrated

PixelStrom: FPGA-Based Image Compositing for Parallel Graphics Systems

This paper describes FGPA-based image combining for parallel graphics systems. The goal of our current work is to reduce network traffic and latency for increasing performance in parallel visualization systems. Initial data distribution is based on a common ethernet network whereas image combining and returning differs to traditional parallel rendering methods. Calculated sub-images are grabbed directly from the DVI-Ports for fast image compositing by a FPGA-based combiner

Virtuelle und Erweiterte Realität. 12. Workshop der GI-Fachgruppe VR/AR

Dieser Tagungsband enthält die Beiträge zum 12. Workshop zum Thema Virtuelle und Erweiterte Realität der Fachgruppe VR/AR der Gesellschaft für Informatik e.V. Der Workshop dient zum Informations- und Ideenaustausch deutschsprachigen WissenschaftlerInnen, zusätzlich bietet der Workshop den idealen Rahmen aktuelle Ergebnisse und Vorhaben aus Forschung und Entwicklung einem fachkundigen Publikum zur Diskussion zu stellen. Insbesondere wollen wir auch jungen Nachwuchswissenschaftlern die Möglichkeit geben, ihre Arbeiten zu präsentieren