Anzahl der Treffer: 167
Erstellt: Tue, 29 Nov 2022 23:15:46 +0100 in 0.0793 sec

Döring, Nicola; Conde, Melisa; Brandenburg, Karlheinz; Broll, Wolfgang; Groß, Horst-Michael; Werner, Stephan; Raake, Alexander
Can communication technologies reduce loneliness and social isolation in older people? : a scoping review of reviews. - In: International journal of environmental research and public health, ISSN 1660-4601, Bd. 19 (2022), 18, 11310, S. 1-20

Background: Loneliness and social isolation in older age are considered major public health concerns and research on technology-based solutions is growing rapidly. This scoping review of reviews aims to summarize the communication technologies (CTs) (review question RQ1), theoretical frameworks (RQ2), study designs (RQ3), and positive effects of technology use (RQ4) present in the research field. Methods: A comprehensive multi-disciplinary, multi-database literature search was conducted. Identified reviews were analyzed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) framework. A total of N = 28 research reviews that cover 248 primary studies spanning 50 years were included. Results: The majority of the included reviews addressed general internet and computer use (82% each) (RQ1). Of the 28 reviews, only one (4%) worked with a theoretical framework (RQ2) and 26 (93%) covered primary studies with quantitative-experimental designs (RQ3). The positive effects of technology use were shown in 55% of the outcome measures for loneliness and 44% of the outcome measures for social isolation (RQ4). Conclusion: While research reviews show that CTs can reduce loneliness and social isolation in older people, causal evidence is limited and insights on innovative technologies such as augmented reality systems are scarce.
Samimi, Niloofar; von der Au, Simon; Weidner, Florian; Broll, Wolfgang
AR in TV: design and evaluation of mid-air gestures for moderators to control augmented reality applications in TV. - In: 20th International Conference on Mobile and Ubiquitous Multimedia, (2022), S. 137-147

Recent developments in augmented reality for TV productions encouraged broadcasters to enhance interaction with virtual content for moderators. However, traditional interaction methods are considered distracting and not intuitive. To overcome these issues, we performed a gesture elicitation study with a follow-up evaluation. For this, we considered TV moderators as primary users of the gestures as well as viewers as recipients. The elicited gesture set consists of five gestures for two types of camera shots (long shot and close shot). Findings of the evaluation study indicate that the derived set of gestures requires low physical and concentration effort from moderators. Also, both moderators and viewers found them appropriate to be used in TV with respect to understandability, distraction, likeability, and appropriateness. Using these gestures would allow moderators to control AR content in TV and tell stories in a modern and more expressive way.
Dörner, Ralf; Broll, Wolfgang; Grimm, Paul; Jung, Bernhard
Virtual and augmented reality (VR/AR) : foundations and methods of extended realities (XR). - Cham, Switzerland : Springer, 2022. - x, 429 Seiten ISBN 3-030-79061-4

Weidner, Florian; Broll, Wolfgang
Stereoscopic 3D dashboards : an investigation of performance, workload, and gaze behavior during take-overs in semi-autonomous driving. - In: Personal and ubiquitous computing, ISSN 1617-4917, Bd. 26 (2022), 3, S. 697-719

When operating a conditionally automated vehicle, humans occasionally have to take over control. If the driver is out of the loop, a certain amount of time is necessary to gain situation awareness. This work evaluates the potential of stereoscopic 3D (S3D) dashboards for presenting smart S3D take-over-requests (TORs) to support situation assessment. In a driving simulator study with a 4 × 2 between-within design, we presented 3 smart TORs showing the current traffic situation and a baseline TOR in 2D and S3D to 52 participants doing the n-back task. We further investigate if non-standard locations affect the results. Take-over performance indicates that participants looked at and processed the TORs' visual information and by that, could perform more safe take-overs. S3D warnings in general, as well as warnings appearing at the participants’ focus of attention and warnings at the instrument cluster, performed best. We conclude that visual warnings, presented on an S3D dashboard, can be a valid option to support take-over while not increasing workload. We further discuss participants’ gaze behavior in the context of visual warnings for automotive user interfaces.
Gerhardt, Christoph; Weidner, Florian; Broll, Wolfgang
OUTSIDE: multi-scale semantic segmentation of universal outdoor scenes. - In: IEEE 23rd International Workshop on Multimedia Signal Processing, (2021), insges. 6 S.

Semantic segmentation aims at providing a fine-grained image prediction by assigning each pixel to a specific semantic category. Convolutional neural networks offer significant benefits for solving this problem. However, the success of such networks is closely related to the availability of corresponding data sets. To facilitate semantic segmentation in a broader range of scenarios, such as augmented reality in outdoor environments or universal image-to-image translation, adequate training data sets are necessary. We present OUTSIDE15k, a large-scale data set for semantic segmentation of universal outdoor scenes. The data is labeled with 24 different semantic classes. The images contain multiple outdoor scenarios and cover a variety of different resolutions. Additionally, we present OUTSIDE-Net, an improved neural network architecture integrating multi-level pooling, feature fusion, and a spatial mask for semantic segmentation of universal outdoor scenes. It extracts spatial and semantic features from the input images to perform the segmentation. With the presented data set, we show the capability of our network which outperforms state-of-the-art approaches by achieving up to 91.5% pixel accuracy.
Döring, Nicola; Mikhailova, Veronika; Brandenburg, Karlheinz; Broll, Wolfgang; Groß, Horst-Michael; Werner, Stephan; Raake, Alexander
Saying "Hi" to grandma in nine different ways : established and innovative communication media in the grandparent-grandchild relationship. - In: Technology, Mind, and Behavior, ISSN 2689-0208, (2021), insges. 1 S.
Nadar, Christon R.; Kunert, Christian; Schwandt, Tobias; Broll, Wolfgang
Sensor simulation for monocular depth estimation using deep neural networks. - In: 2021 International Conference on Cyberworlds, (2021), S. 9-16

Depth estimation is one of the basic building blocks for scene understanding. In the case of monocular depth estimation using neural networks, many such approaches are highly hardware dependent because they result in a task- and environment-specific optimizing problem. Most DNN methods use commonly available datasets which leads to overfitting on particular sensor properties. Finding a generalized model with the consideration of different hardware properties of sensors and platforms is challenging if not impossible. For this reason, it is desirable to adapt existing and well-trained models into a new domain in order to let them simulate different depth sensors without the need for large datasets and time-consuming learning. Therefore, a small dataset has been created with the Structure Sensor for evaluating the transferable structural characteristic between neural networks. Finally, two input feature representations for the neural networks are considered to mimic the depth sensor including its artifacts including holes. The results show that a simple domain adaptation technique and a small dataset are adequate to simulate and adapt to a specific domain from a target domain. Therefore, the network is able to accurately predict depth maps as if they were created by a specific depth sensor. This also includes unique artifacts of the sensor, thereby allowing for a plausible simulation of specific depth sensing hardware which is beneficial for areas like prototyping in the context of Augmented Reality.
Knutzen, Kathrin; Weidner, Florian; Broll, Wolfgang
Exploring augmented reality privacy icons for smart home devices and their effect on users' privacy awareness. - In: 2021 IEEE International Symposium on Mixed and Augmented Reality adjunct proceedings, (2021), S. 409-414

Smart home devices often blend in seamlessly into the environment and operate ubiquitously, providing almost no contextual information such as data collection or activated sensors. Augmented Reality (AR) could, for example in form of head-mounted-displays (HMD), offer users a non-intrusive way to query the devices and to get privacy-related information. This pilot study explored how privacy icons, displayed by an AR-HMD and co-located with smart home devices, affect users' privacy awareness. In a qualitative within-subject study, 16 participants experienced first a setup without AR privacy information and then one with such information. Participants' answers indicate a high potential and excitement towards such a setup. Among others, they stated changed privacy awareness after experiencing AR privacy icons: While the icons prioritized privacy-related information for users and educated them to promote conscious decision-making, they sometimes also reinforced existing negative attitudes towards smart home devices. Further, the display of icons in AR has the potential to inspire trust towards manufacturers and providers, potentially leading to a false sense of security. Next to the discussion of participants' answers, we outline the implications of our findings and provide recommendations for future research including trust and learning effects.
Sharma, Rajat; Schwandt, Tobias; Kunert, Christian; Urban, Steffen; Broll, Wolfgang
Point cloud upsampling and normal estimation using deep learning for robust surface reconstruction. - In: VISIGRAPP 2021, (2021), S. 70-79

The reconstruction of real-world surfaces is on high demand in various applications. Most existing reconstruction approaches apply 3D scanners for creating point clouds which are generally sparse and of low density. These points clouds will be triangulated and used for visualization in combination with surface normals estimated by geometrical approaches. However, the quality of the reconstruction depends on the density of the point cloud and the estimation of the surface normals. In this paper, we present a novel deep learning architecture for point cloud upsampling that enables subsequent stable and smooth surface reconstruction. A noisy point cloud of low density with corresponding point normals is used to estimate a point cloud with higher density and appendant point normals. To this end, we propose a compound loss function that encourages the network to estimate points that lie on a surface including normals accurately predicting the orientation of the surface. Our results show t he benefit of estimating normals together with point positions. The resulting point cloud is smoother, more complete, and the final surface reconstruction is much closer to ground truth.

Schwandt, Tobias;
High-quality illumination of virtual objects based on an environment estimation in mixed reality applications. - Wiesbaden : Springer Vieweg, 2021. - xxvii, 122 Seiten. - (Research)
Technische Universität Ilmenau, Dissertation 2021

ISBN 978-3-658-35191-5

Die Visualisierung virtueller Objekte in der Realität erfolgt bei vielen Anwendungen oftmals durch eine vereinfachte Darstellung ohne Bezug zur umliegenden Umgebung. Dabei ist die nahtlose Verschmelzung der virtuellen und realen Umgebung in vielen Bereichen ein wesentlicher Faktor, der insbesondere bei der Beleuchtungsberechnung in gemischten Realitäten von großer Bedeutung ist. Aktuelle Ansätze legen den Fokus auf Approximationen, welche eine Berechnung der diffusen Beleuchtung ermöglichen, wobei die Darstellung glänzender Beleuchtungseigenschaften vernachlässigt wird. Das Ziel dieser Arbeit ist eine Visualisierung von spiegelnden Oberflächen in erweiterten Realitäten zu ermöglichen. Um dieses Ziel zu erreichen werden verschiedene Verfahren aufgezeigt, die eine hochwertige Darstellung virtueller Objekte in Echtzeit ermöglichen, wobei der Fokus auf der Verwendung üblicher Hardware wie Kameras, Sensoren in mobilen Endgeräten und teilweise Tiefensensoren liegt. Das erste Verfahren verwendet das aktuelle Kamerabild zur Rekonstruktion einer 360-Grad Beleuchtung durch die Transformation des Bildes auf eine Würfelkarte. Anschließend wird dieser Ansatz durch ein Stitching erweitert, bei dem das aktuelle Bild zusammen mit der Position und Rotation der Kamera genutzt wird, um eine Umgebungsbeleuchtung zu erstellen. Dabei von der Kamera nicht erfasste Bereiche werden durch ein semantisches Inpainting, basierend auf einem neuronalen Netz, aufgefüllt. Hierdurch kann das komplette Umgebungslicht approximiert werden, welches die Darstellung detaillierter Reflexionen ermöglicht. Die Ergebnisse der Ansätze zeigen neuartige Möglichkeiten, geometrische Formen mit glänzenden Oberflächen in die reale Umgebung einzubetten und bietet im Vergleich zu bestehenden Methoden einen höheren Detailgrad in den Reflexionen. Alle Ansätze sind für eine Verwendung auf mobilen Endgeräten konzipiert, wodurch neue Möglichkeiten für verschiedene Einsatz- und Anwendungsbereiche der erweiterten Realität existieren.