An Experiment on Multi-Video Transmission with Multipoint Tiled Display Wall, Journal of Telecommunications and Information Technology, 2012, nr 1

In order to realize realistic remote communication between multipoint remote places via the Internet, displaying the appearance of remote participants by transmission of a video streaming with the large-sized display system is effective. However, the display of video streaming with sufficient quality is difficult because the specification of a commercial projector and large-sized display equipment is low-resolution. In order to these issues, we focus on the tiled display wall technology which configure effective wide-area screen system with two or more LCD panels and tried to display a high-resolution video streaming on the large-scale display environment. In this paper, we have constructed remote communication environment with tiled display wall in multipoint sites and have conducted experiment in order to study the possibility of realizing realistic remote communication with multi-video streaming. As these results, these video streaming from each site have been shown to display more high-quality than magnified view of video image by a single small camera. Moreover, we have measured the network throughput performance for each transmitted and received video streaming in this environment. From measurement results, the steady throughput performance has been gained at the case of each transmitted and received video streaming

Spatial displays for visual awareness of remote locations

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. [113]-116).uCom enables remote users to be visually aware of each other using "spatial displays" - live views of a remote space assembled according to an estimate of the remote space's layout. The main elements of the system design are a 3D representation of each space and a multi-display physical setup. The 3D image-based representation of a space is composed of an aggregate of live video feeds acquired from multiple viewpoints and rendered in a graphical visualization resembling a 3D collage. Its navigation controls allow users to transition among the remote views, while maintaining a sense of how the images relate in 3D space. Additionally, the system uses a configurable set of displays to portray always-on visual connections with a remote site integrated into the local physical environment. The evaluation investigates to what extent the system improves users' understanding of the layout of a remote space.by Ana Luisa de Araujo Santos.S.M

Cross-display attention switching in mobile interaction with large displays

Mobile devices equipped with features (e.g., camera, network connectivity and media player) are increasingly being used for different tasks such as web browsing, document reading and photography. While the portability of mobile devices makes them desirable for pervasive access to information, their small screen real-estate often imposes restrictions on the amount of information that can be displayed and manipulated on them. On the other hand, large displays have become commonplace in many outdoor as well as indoor environments. While they provide an efficient way of presenting and disseminating information, they provide little support for digital interactivity or physical accessibility. Researchers argue that mobile phones provide an efficient and portable way of interacting with large displays, and the latter can overcome the limitations of the small screens of mobile devices by providing a larger presentation and interaction space. However, distributing user interface (UI) elements across a mobile device and a large display can cause switching of visual attention and that may affect task performance. This thesis specifically explores how the switching of visual attention across a handheld mobile device and a vertical large display can affect a single user's task performance during mobile interaction with large displays. It introduces a taxonomy based on the factors associated with the visual arrangement of Multi Display User Interfaces (MDUIs) that can influence visual attention switching during interaction with MDUIs. It presents an empirical analysis of the effects of different distributions of input and output across mobile and large displays on the user's task performance, subjective workload and preference in the multiple-widget selection task, and in visual search tasks with maps, texts and photos. Experimental results show that the selection of multiple widgets replicated on the mobile device as well as on the large display, versus those shown only on the large display, is faster despite the cost of initial attention switching in the former. On the other hand, a hybrid UI configuration where the visual output is distributed across the mobile and large displays is the worst, or equivalent to the worst, configuration in all the visual search tasks. A mobile device-controlled large display configuration performs best in the map search task and equal to best (i.e., tied with a mobile-only configuration) in text- and photo-search tasks

Journal of Telecommunications and Information Technology, 2012, nr 1

kwartalni

Do You Know What I Know?:Situational Awareness of Co-located Teams in Multidisplay Environments

Modern collaborative environments often provide an overwhelming amount of visual information on multiple displays. In complex project settings, the amount of visual information on multiple displays, and the multitude of personal and shared interaction devices in these environments can reduce the awareness of team members on ongoing activities, the understanding of shared visualisations, and the awareness of who is in control of shared artifacts. Research reported in this thesis addresses the situational awareness (SA) support of co-located teams working on team projects in multidisplay environments. Situational awareness becomes even more critical when the content of multiple displays changes rapidly, and when these provide large amounts of information. This work aims at getting insights into design and evaluation of shared display visualisations that afford situational awareness and group decision making. This thesis reports the results of three empirical user studies in three different domains: life science experimentation, decision making in brainstorming teams, and agile software development. The first and the second user studies evaluate the impact of the Highlighting-on-Demand and the Chain-of-Thoughts SA on the group decision-making and awareness. The third user study presents the design and evaluation of a shared awareness display for software teams. Providing supportive visualisations on a shared large display, we aimed at reducing the distraction from the primary task, enhancing the group decision-making process and the perceived task performance

Situated Displays in Telecommunication

In face to face conversation, numerous cues of attention, eye contact, and gaze direction provide important channels of information. These channels create cues that include turn taking, establish a sense of engagement, and indicate the focus of conversation. However, some subtleties of gaze can be lost in common videoconferencing systems, because the single perspective view of the camera doesn't preserve the spatial characteristics of the face to face situation. In particular, in group conferencing, the `Mona Lisa effect' makes all observers feel that they are looked at when the remote participant looks at the camera. In this thesis, we present designs and evaluations of four novel situated teleconferencing systems, which aim to improve the teleconferencing experience. Firstly, we demonstrate the effectiveness of a spherical video telepresence system in that it allows a single observer at multiple viewpoints to accurately judge where the remote user is placing their gaze. Secondly, we demonstrate the gaze-preserving capability of a cylindrical video telepresence system, but for multiple observers at multiple viewpoints. Thirdly, we demonstrated the further improvement of a random hole autostereoscopic multiview telepresence system in conveying gaze by adding stereoscopic cues. Lastly, we investigate the influence of display type and viewing angle on how people place their trust during avatar-mediated interaction. The results show the spherical avatar telepresence system has the ability to be viewed qualitatively similarly from all angles and demonstrate how trust can be altered depending on how one views the avatar. Together these demonstrations motivate the further study of novel display configurations and suggest parameters for the design of future teleconferencing systems

Interactive Visualization on High-Resolution Tiled Display Walls with Network Accessible Compute- and Display-Resources

Papers number 2-7 and appendix B and C of this thesis are not available in Munin: 2. Hagen, T-M.S., Johnsen, E.S., Stødle, D., Bjorndalen, J.M. and Anshus, O.: 'Liberating the Desktop', First International Conference on Advances in Computer-Human Interaction (2008), pp 89-94. Available at http://dx.doi.org/10.1109/ACHI.2008.20 3. Tor-Magne Stien Hagen, Oleg Jakobsen, Phuong Hoai Ha, and Otto J. Anshus: 'Comparing the Performance of Multiple Single-Cores versus a Single Multi-Core' (manuscript)4. Tor-Magne Stien Hagen, Phuong Hoai Ha, and Otto J. Anshus: 'Experimental Fault-Tolerant Synchronization for Reliable Computation on Graphics Processors' (manuscript) 5. Tor-Magne Stien Hagen, Daniel Stødle and Otto J. Anshus: 'On-Demand High-Performance Visualization of Spatial Data on High-Resolution Tiled Display Walls', Proceedings of the International Conference on Imaging Theory and Applications and International Conference on Information Visualization Theory and Applications (2010), pages 112-119. Available at http://dx.doi.org/10.5220/0002849601120119 6. Bård Fjukstad, Tor-Magne Stien Hagen, Daniel Stødle, Phuong Hoai Ha, John Markus Bjørndalen and Otto Anshus: 'Interactive Weather Simulation and Visualization on a Display Wall with Many-Core Compute Nodes', Para 2010 – State of the Art in Scientific and Parallel Computing. Available at http://vefir.hi.is/para10/extab/para10-paper-60 7. Tor-Magne Stien Hagen, Daniel Stødle, John Markus Bjørndalen, and Otto Anshus: 'A Step towards Making Local and Remote Desktop Applications Interoperable with High-Resolution Tiled Display Walls', Lecture Notes in Computer Science (2011), Volume 6723/2011, 194-207. Available at http://dx.doi.org/10.1007/978-3-642-21387-8_15The vast volume of scientific data produced today requires tools that can enable scientists to explore large amounts of data to extract meaningful information. One such tool is interactive visualization. The amount of data that can be simultaneously visualized on a computer display is proportional to the display’s resolution. While computer systems in general have seen a remarkable increase in performance the last decades, display resolution has not evolved at the same rate. Increased resolution can be provided by tiling several displays in a grid. A system comprised of multiple displays tiled in such a grid is referred to as a display wall. Display walls provide orders of magnitude more resolution than typical desktop displays, and can provide insight into problems not possible to visualize on desktop displays. However, their distributed and parallel architecture creates several challenges for designing systems that can support interactive visualization. One challenge is compatibility issues with existing software designed for personal desktop computers. Another set of challenges include identifying characteristics of visualization systems that can: (i) Maintain synchronous state and display-output when executed over multiple display nodes; (ii) scale to multiple display nodes without being limited by shared interconnect bottlenecks; (iii) utilize additional computational resources such as desktop computers, clusters and supercomputers for workload distribution; and (iv) use data from local and remote compute- and data-resources with interactive performance. This dissertation presents Network Accessible Compute (NAC) resources and Network Accessible Display (NAD) resources for interactive visualization of data on displays ranging from laptops to high-resolution tiled display walls. A NAD is a display having functionality that enables usage over a network connection. A NAC is a computational resource that can produce content for network accessible displays. A system consisting of NACs and NADs is either push-based (NACs provide NADs with content) or pull-based (NADs request content from NACs). To attack the compatibility challenge, a push-based system was developed. The system enables several simultaneous users to mirror multiple regions from the desktop of their computers (NACs) onto nearby NADs (among others a 22 megapixel display wall) without requiring usage of separate DVI/VGA cables, permanent installation of third party software or opening firewall ports. The system has lower performance than that of a DVI/VGA cable approach, but increases flexibility such as the possibility to share network accessible displays from multiple computers. At a resolution of 800 by 600 pixels, the system can mirror dynamic content between a NAC and a NAD at 38.6 frames per second (FPS). At 1600x1200 pixels, the refresh rate is 12.85 FPS. The bottleneck of the system is frame buffer capturing and encoding/decoding of pixels. These two functional parts are executed in sequence, limiting the usage of additional CPU cores. By pipelining and executing these parts on separate CPU cores, higher frame rates can be expected and by a factor of two in the best case. To attack all presented challenges, a pull-based system, WallScope, was developed. WallScope enables interactive visualization of local and remote data sets on high-resolution tiled display walls. The WallScope architecture comprises a compute-side and a display-side. The compute-side comprises a set of static and dynamic NACs. Static NACs are considered permanent to the system once added. This type of NAC typically has strict underlying security and access policies. Examples of such NACs are clusters, grids and supercomputers. Dynamic NACs are compute resources that can register on-the-fly to become compute nodes in the system. Examples of this type of NAC are laptops and desktop computers. The display-side comprises of a set of NADs and a data set containing data customized for the particular application domain of the NADs. NADs are based on a sort-first rendering approach where a visualization client is executed on each display-node. The state of these visualization clients is provided by a separate state server, enabling central control of load and refresh-rate. Based on the state received from the state server, the visualization clients request content from the data set. The data set is live in that it translates these requests into compute messages and forwards them to available NACs. Results of the computations are returned to the NADs for the final rendering. The live data set is close to the NADs, both in terms of bandwidth and latency, to enable interactive visualization. WallScope can visualize the Earth, gigapixel images, and other data available through the live data set. When visualizing the Earth on a 28-node display wall by combining the Blue Marble data set with the Landsat data set using a set of static NACs, the bottleneck of WallScope is the computation involved in combining the data sets. However, the time used to combine data sets on the NACs decreases by a factor of 23 when going from 1 to 26 compute nodes. The display-side can decode 414.2 megapixels of images per second (19 frames per second) when visualizing the Earth. The decoding process is multi-threaded and higher frame rates are expected using multi-core CPUs. WallScope can rasterize a 350-page PDF document into 550 megapixels of image-tiles and display these image-tiles on a 28-node display wall in 74.66 seconds (PNG) and 20.66 seconds (JPG) using a single quad-core desktop computer as a dynamic NAC. This time is reduced to 4.20 seconds (PNG) and 2.40 seconds (JPG) using 28 quad-core NACs. This shows that the application output from personal desktop computers can be decoupled from the resolution of the local desktop and display for usage on high-resolution tiled display walls. It also shows that the performance can be increased by adding computational resources giving a resulting speedup of 17.77 (PNG) and 8.59 (JPG) using 28 compute nodes. Three principles are formulated based on the concepts and systems researched and developed: (i) Establishing the end-to-end principle through customization, is a principle stating that the setup and interaction between a display-side and a compute-side in a visualization context can be performed by customizing one or both sides; (ii) Personal Computer (PC) – Personal Compute Resource (PCR) duality states that a user’s computer is both a PC and a PCR, implying that desktop applications can be utilized locally using attached interaction devices and display(s), or remotely by other visualization systems for domain specific production of data based on a user’s personal desktop install; and (iii) domain specific best-effort synchronization stating that for distributed visualization systems running on tiled display walls, state handling can be performed using a best-effort synchronization approach, where visualization clients eventually will get the correct state after a given period of time. Compared to state-of-the-art systems presented in the literature, the contributions of this dissertation enable utilization of a broader range of compute resources from a display wall, while at the same time providing better control over where to provide functionality and where to distribute workload between compute-nodes and display-nodes in a visualization context

Videos in Context for Telecommunication and Spatial Browsing

The research presented in this thesis explores the use of videos embedded in panoramic imagery to transmit spatial and temporal information describing remote environments and their dynamics. Virtual environments (VEs) through which users can explore remote locations are rapidly emerging as a popular medium of presence and remote collaboration. However, capturing visual representation of locations to be used in VEs is usually a tedious process that requires either manual modelling of environments or the employment of specific hardware. Capturing environment dynamics is not straightforward either, and it is usually performed through specific tracking hardware. Similarly, browsing large unstructured video-collections with available tools is difficult, as the abundance of spatial and temporal information makes them hard to comprehend. At the same time, on a spectrum between 3D VEs and 2D images, panoramas lie in between, as they offer the same 2D images accessibility while preserving 3D virtual environments surrounding representation. For this reason, panoramas are an attractive basis for videoconferencing and browsing tools as they can relate several videos temporally and spatially. This research explores methods to acquire, fuse, render and stream data coming from heterogeneous cameras, with the help of panoramic imagery. Three distinct but interrelated questions are addressed. First, the thesis considers how spatially localised video can be used to increase the spatial information transmitted during video mediated communication, and if this improves quality of communication. Second, the research asks whether videos in panoramic context can be used to convey spatial and temporal information of a remote place and the dynamics within, and if this improves users' performance in tasks that require spatio-temporal thinking. Finally, the thesis considers whether there is an impact of display type on reasoning about events within videos in panoramic context. These research questions were investigated over three experiments, covering scenarios common to computer-supported cooperative work and video browsing. To support the investigation, two distinct video+context systems were developed. The first telecommunication experiment compared our videos in context interface with fully-panoramic video and conventional webcam video conferencing in an object placement scenario. The second experiment investigated the impact of videos in panoramic context on quality of spatio-temporal thinking during localization tasks. To support the experiment, a novel interface to video-collection in panoramic context was developed and compared with common video-browsing tools. The final experimental study investigated the impact of display type on reasoning about events. The study explored three adaptations of our video-collection interface to three display types. The overall conclusion is that videos in panoramic context offer a valid solution to spatio-temporal exploration of remote locations. Our approach presents a richer visual representation in terms of space and time than standard tools, showing that providing panoramic contexts to video collections makes spatio-temporal tasks easier. To this end, videos in context are suitable alternative to more difficult, and often expensive solutions. These findings are beneficial to many applications, including teleconferencing, virtual tourism and remote assistance

Remote Visual Observation of Real Places Through Virtual Reality Headsets

Virtual Reality has always represented a fascinating yet powerful opportunity that has attracted studies and technology developments, especially since the latest release on the market of powerful high-resolution and wide field-of-view VR headsets. While the great potential of such VR systems is common and accepted knowledge, issues remain related to how to design systems and setups capable of fully exploiting the latest hardware advances. The aim of the proposed research is to study and understand how to increase the perceived level of realism and sense of presence when remotely observing real places through VR headset displays. Hence, to produce a set of guidelines that give directions to system designers about how to optimize the display-camera setup to enhance performance, focusing on remote visual observation of real places. The outcome of this investigation represents unique knowledge that is believed to be very beneficial for better VR headset designs towards improved remote observation systems. To achieve the proposed goal, this thesis presents a thorough investigation of existing literature and previous researches, which is carried out systematically to identify the most important factors ruling realism, depth perception, comfort, and sense of presence in VR headset observation. Once identified, these factors are further discussed and assessed through a series of experiments and usability studies, based on a predefined set of research questions. More specifically, the role of familiarity with the observed place, the role of the environment characteristics shown to the viewer, and the role of the display used for the remote observation of the virtual environment are further investigated. To gain more insights, two usability studies are proposed with the aim of defining guidelines and best practices. The main outcomes from the two studies demonstrate that test users can experience an enhanced realistic observation when natural features, higher resolution displays, natural illumination, and high image contrast are used in Mobile VR. In terms of comfort, simple scene layouts and relaxing environments are considered ideal to reduce visual fatigue and eye strain. Furthermore, sense of presence increases when observed environments induce strong emotions, and depth perception improves in VR when several monocular cues such as lights and shadows are combined with binocular depth cues. Based on these results, this investigation then presents a focused evaluation on the outcomes and introduces an innovative eye-adapted High Dynamic Range (HDR) approach, which the author believes to be of great improvement in the context of remote observation when combined with eye-tracked VR headsets. Within this purpose, a third user study is proposed to compare static HDR and eye-adapted HDR observation in VR, to assess that the latter can improve realism, depth perception, sense of presence, and in certain cases even comfort. Results from this last study confirmed the author expectations, proving that eye-adapted HDR and eye tracking should be used to achieve best visual performances for remote observation in modern VR systems