Mobile collaborative video

The emergence of pico projectors as a part of future mobile devices presents unique opportunities for collaborative settings, especially in entertainment applications, such as video playback. By aggregating pico projectors from several users, it is possible to enhance resolution, brightness, or frame rate. In this paper we present a camera-based methodology for the alignment and synchronization of multiple projectors. The approach does not require any complicated ad hoc network setup among the mobile devices. A prototype system has been set up and used to test the proposed techniques

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

Design of a Scenario-Based Immersive Experience Room

open1noopenKlopfenstein, Cuno LorenzKlopfenstein, CUNO LOREN

Interactive ubiquitous displays based on steerable projection

The ongoing miniaturization of computers and their embedding into the physical environment require new means of visual output. In the area of Ubiquitous Computing, flexible and adaptable display options are needed in order to enable the presentation of visual content in the physical environment. In this dissertation, we introduce the concepts of Display Continuum and Virtual Displays as new means of human-computer interaction. In this context, we present a realization of a Display Continuum based on steerable projection, and we describe a number of different interaction methods for manipulating this Display Continuum and the Virtual Displays placed on it.Mit zunehmender Miniaturisierung der Computer und ihrer Einbettung in der physikalischen Umgebung werden neue Arten der visuellen Ausgabe notwendig. Im Bereich des Ubiquitous Computing (Rechnerallgegenwart) werden flexible und anpassungsfähige Displays benötigt, um eine Anzeige von visuellen Inhalten unmittelbar in der physikalischen Umgebung zu ermöglichen. In dieser Dissertation führen wir das Konzept des Display-Kontinuums und der Virtuellen Displays als Instrument der Mensch-Maschine-Interaktion ein. In diesem Zusammenhang präsentieren wir eine mögliche Display-Kontinuum-Realisierung, die auf der Verwendung steuerbarer Projektion basiert, und wir beschreiben mehrere verschiedene Interaktionsmethoden, mit denen man das Display-Kontinuum und die darauf platzierten Virtuellen Displays steuern kann

08231 Abstracts Collection -- Virtual Realities

From 1st to 6th June 2008, the Dagstuhl Seminar 08231 ``Virtual Realities\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. Virtual Reality (VR) is a multidisciplinary area of research aimed at interactive human-computer mediated simulations of artificial environments. Typical applications include simulation, training, scientific visualization, and entertainment. An important aspect of VR-based systems is the stimulation of the human senses -- typically sight, sound, and touch -- such that a user feels a sense of presence (or immersion) in the virtual environment. Different applications require different levels of presence, with corresponding levels of realism, sensory immersion, and spatiotemporal interactive fidelity. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. Links to extended abstracts or full papers are provided, if available

Content creation for seamless augmented experiences with projection mapping

This dissertation explores systems and methods for creating projection mapping content that seamlessly merges virtual and physical. Most virtual reality and augmented reality technologies rely on screens for display and interaction, where a mobile device or head mounted display mediates the user's experience. In contrast, projection mapping uses off-the-shelf video projectors to augment the appearance of physical objects, and with projection mapping there is no screen to mediate the experience. The physical world simply becomes the display. Projection mapping can provide users with a seamless augmented experience, where virtual and physical become indistinguishable in an apparently unmediated way. Projection mapping is an old concept dating to Disney's 1969 Haunted Mansion. The core technical foundations were laid back in 1999 with UNC's Office of the Future and Shader Lamps projects. Since then, projectors have gotten brighter, higher resolution, and drastically decreased in price. Yet projection mapping has not crossed the chasm into mainstream use. The largest remaining challenge for projection mapping is that content creation is very difficult and time consuming. Content for projection mapping is still created via a tedious manual process by warping a 2D video file onto a 3D physical object using existing tools (e.g. Adobe Photoshop) which are not made for defining animated interactive effects on 3D object surfaces. With existing tools, content must be created for each specific display object, and cannot be re-used across experiences. For each object the artist wants to animate, the artist must manually create a custom texture for that specific object, and warp the texture to the physical object. This limits projection mapped experiences to controlled environments and static scenes. If the artist wants to project onto a different object from the original, they must start from scratch creating custom content for that object. This manual content creation process is time consuming, expensive and doesn't scale. This thesis explores new methods for creating projection mapping content. Our goal is to make projection mapping easier, cheaper and more scalable. We explore methods for adaptive projection mapping, which enables artists to create content once, and that content adapts based on the color and geometry of the display surface. Content can be created once, and re-used on any surface. This thesis is composed of three proof-of-concept prototypes, exploring new methods for content creation for projection mapping. IllumiRoom expands video game content beyond the television screen and into the physical world using a standard video projector to surround a television with projected light. IllumiRoom works in any living room, the projected content dynamically adapts based on the color and geometry of the room. RoomAlive expands on this idea, using multiple projectors to cover an entire living room in input/output pixels and dynamically adapts gaming experiences to fill an entire room. Finally, Projectibles focuses on the physical aspect of projection mapping. Projectibles optimizes the display surface color to increase the contrast and resolution of the overall experience, enabling artists to design the physical object along with the virtual content. The proof-of-concept prototypes presented in this thesis are aimed at the not-to-distant future. The projects in this thesis are not theoretical concepts, but fully working prototype systems that demonstrate the practicality of projection mapping to create immersive experiences. It is the sincere hope of the author that these experiences quickly move of the lab and into the real world

Multiple viewers in projection-based multi-screen immersive environments

Projection-based immersive virtual environments are very powerful tools to work on engineering and scientific problems involving teams of researchers. These environments enable the development of virtual representations of a problem domain in which multiple users can simultaneously share a virtual experience, providing a unique infrastructure for team work. The current limitation for effective teamwork is that these systems support only a single viewpoint, usually corresponding to a user wearing a head tracking device. This thesis presents a hardware and software design to enable multiple simultaneous viewpoints in a multi-screen immersive environment. This system is designed to be flexible and easily scalable, preparing for future expansion to additional users when the underlying technologies allow it. The design extends the commonly used single user time-multiplexed stereo viewing model to multiple users. This research also extends existing development tools to support our multiple viewer virtual design. This work also focuses on extending existing applications to multiple viewer environments. A design and implementation of the system is presented in detail. This system enables two users viewing stereoscopic images or four users viewing monoscopic images to simultaneously view the correct images projected on the screen from their tracked viewpoint

Algorithms for a multi-projector CAVE system

With regards to facilitating development of VR applications, the main pur- pose of ALIVE is to reduce the amount of attention that the application developer has to dedicate to the issues that were described previously. In this project we aim to abstract the user from dealing with: Input devices. Display number and layout. De nition of the virtual cameras. Synchronization issues between cluster nodes. Notably missing from the list are 3D sound rendering and synchroniza- tion for non-deterministic algorithms. These problems are out of the scope of this project and will be addressed in the future. Summarizing the objectives of this project, we list: Provide an abstraction API, that facilitates development and deploy- ment of VR applications. Create a polygon renderer application based on the proposed API

Journal of Telecommunications and Information Technology, 2012, nr 1

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