Evaluating and Improving Image Quality of Tiled Displays

Tiled displays are created by grouping multiple displays together to form one very large display. These tiled displays are often the only suitable option for displaying very large images but suffer from a grid distortion caused by gaps between each sub-display’s active region. This grid distortion is fundamentally different from other, well-studied, image distortions (e.g., blur, noise, compression) and the impact of these grid distortions has thus far not been studied. This research addresses this lack of attention by investigating the grid distortion’s quality impact and creating perceptual algorithms to reduce this impact. We measure the quality impact of the grid distortion by creating two new image quality assessment (IQA) databases for tiled images. These databases provide significant insight into the unique characteristics of the grid distortion and provide a baseline against which to measure the performance of current IQA metrics. We use these databases to show that current metrics do not adequately reflect the quality impact of the grid distortions, and we create a new metric specifically for tiled images that statistically (with 95% confidence) outperforms current metrics. We improve perceived tiled display image quality by creating new image-correction algorithms based on elements of the human visual system (HVS). These correction techniques modify the perceived quality of the displayed images without directly modifying the static grid distortion. These algorithms are shown, through the use of a third subjective user study, to clearly and consistently improve the perceived quality of tiled images.1 yea

Using high resolution displays for high resolution cardiac data

The ability to perform fast, accurate, high resolution visualization is fundamental to improving our understanding of anatomical data. As the volumes of data increase from improvements in scanning technology, the methods applied to rendering and visualization must evolve. In this paper we address the interactive display of data from high resolution MRI scanning of a rabbit heart and subsequent histological imaging. We describe a visualization environment involving a tiled LCD panel display wall and associated software which provide an interactive and intuitive user interface. The oView software is an OpenGL application which is written for the VRJuggler environment. This environment abstracts displays and devices away from the application itself, aiding portability between different systems, from desktop PCs to multi-tiled display walls. Portability between display walls has been demonstrated through its use on walls at both Leeds and Oxford Universities. We discuss important factors to be considered for interactive 2D display of large 3D datasets, including the use of intuitive input devices and level of detail aspects

A multi-projector CAVE system with commodity hardware and gesture-based interaction

Spatially-immersive systems such as CAVEs provide users with surrounding worlds by projecting 3D models on multiple screens around the viewer. Compared to alternative immersive systems such as HMDs, CAVE systems are a powerful tool for collaborative inspection of virtual environments due to better use of peripheral vision, less sensitivity to tracking errors, and higher communication possibilities among users. Unfortunately, traditional CAVE setups require sophisticated equipment including stereo-ready projectors and tracking systems with high acquisition and maintenance costs. In this paper we present the design and construction of a passive-stereo, four-wall CAVE system based on commodity hardware. Our system works with any mix of a wide range of projector models that can be replaced independently at any time, and achieves high resolution and brightness at a minimum cost. The key ingredients of our CAVE are a self-calibration approach that guarantees continuity across the screen, as well as a gesture-based interaction approach based on a clever combination of skeletal data from multiple Kinect sensors.Preprin

Analyzing autostereoscopic environment confgurations for the design of videogames

Stereoscopic devices are becoming more popular every day. The 3D visualization that these displays ofer is being used by videogame designers to enhance the user’s game experience. Autostereoscopic monitors ofer the possibility of obtaining this 3D visualization without the need for extra device. This fact makes them more attractive to videogame developers. However, the confguration of the cameras that make it possible to obtain an immersive 3D visualization inside the game is still an open problem. In this paper, some system confgurations that create autostereoscopic visualization in a 3D game engine were evaluated to obtain a good accommodation of the user experience with the game. To achieve this, user tests that take into account the movement of the player were carried out to evaluate diferent camera confgurations, namely, dynamic and static converging optical axis and parallel optical axis. The purpose of these tests is to evaluate the user experience regarding visual discomfort resulting from the movement of the objects, with the purpose of assessing the preference for one confguration or the other. The results show that the users tend to have a preference trend for the parallel optical axis confguration set. This confguration seems to be optimal because the area where the moving objects are focused is deeper than in the other confgurations

Perception and Mitigation of Artifacts in a Flat Panel Tiled Display System

Flat panel displays continue to dominate the display market. Larger, higher resolution flat panel displays are now in demand for scientific, business, and entertainment purposes. Manufacturing such large displays is currently difficult and expensive. Alternately, larger displays can be constructed by tiling smaller flat panel displays. While this approach may prove to be more cost effective, appropriate measures must be taken to achieve visual seamlessness and uniformity. In this project we conducted a set of experiments to study the perception and mitigation of image artifacts in tiled display systems. In the first experiment we used a prototype tiled display to investigate its current viability and to understand what critical perceptible visual artifacts exist in this system. Based on word frequencies of the survey responses, the most disruptive artifacts perceived were ranked. On the basis of these findings, we conducted a second experiment to test the effectiveness of image processing algorithms designed to mitigate some of the most distracting artifacts without changing the physical properties of the display system. Still images were processed using several algorithms and evaluated by observers using magnitude scaling. Participants in the experiment noticed statistically significant improvement in image quality from one of the two algorithms. Similar testing should be conducted to evaluate the effectiveness of the algorithms on video content. While much work still needs to be done, the contributions of this project should enable the development of an image processing pipeline to mitigate perceived artifacts in flat panel display systems and provide the groundwork for extending such a pipeline to realtime applications

Imaging and visualization at the University of Missouri--Columbia

"The following group of faculty helped prepare this document for MU’s Cyberinfrastructure (CI) Council as part of the 2016 updates to MU’s CI Plan. ... Bimal Balakrishnan, Tommi White, Teresa Lever, David Larsen, Kannappan Palaniappan, Filiz Bunyak, and Chi-Ren ShyuThe document includes a long-term vision for a Show-Me Center for Imaging and Visualization (see page 7). For consistency, with the other parts of the CI Plan, one and three year objectives are provided. This document is designed to help update the CI Plan, and help advance the growing momentum for a imaging and visualization center to support faculty and students from a wide-variety of discipline, and advance a variety of innovative collaborations.Imaging and Visualization and the University of Missouri (MU) -- Return on Proposed Investment -- Imaging and Visualization Needs and Recommendations -- Cross connections with other areas of emphasis in the MU Cyberinfrastructure Plan -- One Year Objectives -- Three to Five Year Objectives -- The Big Picture: the Show-Me Center for Imaging and Visualization. Physical Space ; Where to Start and Why ; Visualization Related ; Infrastructure needed at MU ; Computation, Data Storage and Networking needs ; Management, Staffing, Training and Support ; Needed expertise -- Appendix A: Faculty Perspectives on the Importance of Visualization on Research and Teaching at MU -- Appendix B: Comparable Imaging Facilities -- Appendix C: Visualization Centers at Major Research Universities