Tiled Display Research Articles

P‐260L: Late‐News Poster: Design of Multi‐Screen RGBW LCDs for Information Displays

AbstractA 2×2 module prototype is developed with four 15‐inch RGBW LCDs. Transmittance of LCD is increased with the low resolution, that is, qXGA(512×RG×384×BW). Using a new RGBW conversion algorithm, white and R/G/B luminance are increased 270% and 130% respectively in comparison with the 15‐inch conventional RGB LCD. An electronics system is implemented and a GUI is developed to support the hardware image control for tiled display.

36.4: A Novel Seamless Tiling Technology for High Resolution OLED Displays

AbstractA novel seamless tiling technology for high resolution OLED displays is described. This technology is mainly based on geometric arrangement of each pixels and optical path control of OLED displays. Computer simulations have been used to find and confirm the best conditions for seamless OLED displays. A 2 × 1 tiled, 72ppi resolution, 8″ diagonal size AM‐OLED seamless tiled display prototype was fabricated.

RESEARCH OF NESTED PARALLEL PIPELINES ON PARALLEL GRAPHICS RENDERING SYSTEM

Existing parallel graphics rendering systems only support single level parallel rendering pipeline. This paper presents a novel high performance parallel graphics rendering architecture on PC-Cluster supporting tiled display wall. It employs a hybrid sort-first and sort-last architecture based on a new rendering and scheduling structure, called dynamic rendering team (DRT as abbreviation), which is composed of multiple PCs instead of single PC to act as a rendering node. Each DRT responds for a certain projector area in the tiled display wall and all DRTs form a outer level parallel rendering pipeline natively. Inside separate DRT there is an optimized parallel Rendering-Composing-Display (R-C-D) pipeline reconstructing the serial workflow to parallel one. The Optimized parallel R-C-D pipeline along with the outer parallel rendering pipelines among DRTs forms a special nested parallel pipeline architecture, which promotes the whole rendering performance of our system greatly. Experiments show that parallel rendering system with the proposed architecture and nested parallel rendering pipelines, called Parallel-SG, can render over 13M triangles at an average speed of 12 frames per second without any accelerating technologies on a tile-display wall of 5*3 projectors array.

전 분류 기법과 후 분류 기법의 조합을 통한 효율적 병렬 타일 가시화 알고리듬 개발

본 논문에서는 고해상도 타일 가시화 시스템의 성능 향상을 위해 전 분류 기법과 후 분류 기법을 조합하여 두 가지 병렬-타일 가시화 알고리듬을 제안하였다. 전 분류에서는 디스플레이 리스트와 시각 절두체 선별 기법을 이용하였으며, 후 분류에서는 선 탐색 부분 후 분류기법을 이용하였다. 벤치마킹 테스트를 통해 제안된 두 병렬-타일 가시화 기법의 성능을 고찰하였으며, 이 결과를 기반으로 제안된 두 가지 병렬-타일 가시화 알고리듬 중에서 주어진 가시화 모델에 대해 더 효율적인 알고리듬을 선정하는 방안을 제시하였다. To improve the performance of tiled display system, two parallel tiled display algorithms are proposed by combining the sort-first and the sort-last sorting methods. In the proposed algorithms, the view frustum culling is employed along with the OpenGL display list for the sort-first sorting, and the pre-detection sort-last sparse sorting method is used for sort-last sorting. Through the benchmarking tests, the performances of two proposed algorithms are investigated. Based on the observations, it is suggested how to select an optimal algorithm among the two proposed parallel tiled display algorithms for the given visualization model.

3차원 사용자 인터페이스 장비와 PC 클러스터 환경 타일 가시화 시스템의 효율적인 연동

본 논문에서는 3차원 사용자 인터페이스를 PC 클러스터에 기반한 타일 가시화 시스템에 효율적으로 연동시킬 수 있는 방법을 제안하였다. 사용자 편의성을 증대하기 위해 개발된 3차원 사용자 인터페이스 소프트웨어에는 모델 자세조종 명령어를 비롯한 각종 메뉴가 포함되어있으며, 3차원 사용자 인터페이스 장비에서 발생되는 신호 잡음을 없애기 위해 박스형 필터를 사용하였다. 또한 타일 가시화 시스템과 3차원 사용자 인터페이스 사이에서 신호 대기로 인해 발생하는 모델 운동 지연 문제를 해결하기 위해 비동기식 통신형태에 기반한 새로운 ‘통신 분리’ 알고리듬을 제안하였으며, 검증 테스트를 통해 제안된 방안의 효율성을 확인하였다. In this paper, an efficient technique is proposed to integrate the 3D user interface with the tiled display system in PC cluster environment. In the developed 3D user interface software, various menus are provided to increase the user friendliness of the interface, including the several model-control-commands. To eliminate the noise produced from the 3D user interface devices, the box filtering algorithm is employed. Further, a communication splitting algorithm, which is a kind of asynchronous communication method, is proposed to reduce the motion delay between the 3D interface and the tiled display system, and its efficiency is validated through the benchmarking tests.

Spatially uniform colors for projectors and tiled displays

Abstract— A major issue when setting up multi‐projector tiled displays is the spatial non‐uniformity of the color throughout the display's area. Indeed, the chromatic properties do not only vary between two different projectors, but also between different spatial locations inside the displaying area of one single projector. A new method for calibrating the colors of a tiled display is presented. An iterative algorithm to construct a correction table which makes the luminance uniform over the projected area of one single projector is presented first. This so‐called intra‐projector calibration uses a standard camera as a luminance measuring device and can be processed in parallel for all projectors. Once the color inside each projector is spatially uniform, the set of displayable colors — the color gamut — of each projector is measured. On the basis of these measurements, the goal of the inter‐projector calibration is to find an optimal gamut shared by all the projectors. Finding the optimal color gamut displayable by n projectors in time O(n) is shown, and the color conversion from one specific color gamut to the common global gamut is derived. The method of testing it on a tiled display consisting of 48 projectors with large chrominance shifts was experimentally validated.

Garuda: A Scalable Tiled Display Wall Using Commodity PCs

Cluster-based tiled display walls can provide cost-effective and scalable displays with high resolution and a large display area. The software to drive them needs to scale too if arbitrarily large displays are to be built. Chromium is a popular software API used to construct such displays. Chromium transparently renders any OpenGL application to a tiled display by partitioning and sending individual OpenGL primitives to each client per frame. Visualization applications often deal with massive geometric data with millions of primitives. Transmitting them every frame results in huge network requirements that adversely affect the scalability of the system. In this paper, we present Garuda, a client-server-based display wall framework that uses off-the-shelf hardware and a standard network. Garuda is scalable to large tile configurations and massive environments. It can transparently render any application built using the Open Scene Graph (OSG) API to a tiled display without any modification by the user. The Garuda server uses an object-based scene structure represented using a scene graph. The server determines the objects visible to each display tile using a novel adaptive algorithm that culls the scene graph to a hierarchy of frustums. Required parts of the scene graph are transmitted to the clients, which cache them to exploit the interframe redundancy. A multicast-based protocol is used to transmit the geometry to exploit the spatial redundancy present in tiled display systems. A geometry push philosophy from the server helps keep the clients in sync with one another. Neither the server nor a client needs to render the entire scene, making the system suitable for interactive rendering of massive models. Transparent rendering is achieved by intercepting the cull, draw, and swap functions of OSG and replacing them with our own. We demonstrate the performance and scalability of the Garuda system for different configurations of display wall. We also show that the server and network loads grow sublinearly with the increase in the number of tiles, which makes our scheme suitable to construct very large displays.

An exhibition storytelling with the use of tiled display

An exhibition storytelling with the use of tiled display

Dynamic visualization of high resolution GIS dataset on multi-panel display using ArcGIS engine

Geographic information systems (GIS) and remote sensing (RS) have been used extensively in many land surveying and natural resources management applications. With ever-advancing technology, geospatial data collection is done at increasingly wide extent and finer resolution. A single remotely-sensed image and other raster data can easily exceed a gigabyte (GB), which further challenges the storage, manipulation, and visualization of such data even on high-end computer systems. One approach to processing and handling display of these huge datasets is through clustered computing and rendering. In this project, we proposed and implemented a multi-panel visualization mechanism that allows dynamic visualization of large, high resolution GIS datasets using ESRI ® ArcGIS ® Engine. The multi-panel display system is composed of a seven-personal computer (PC) (or seven-node) cluster. Six PCs (referred to as, render nodes or client nodes) display output forming the tiled display and the seventh PC (master node) serves as the master control. The client nodes are controlled by the master node to achieve synchronous visualization of GIS data rendered in the ESRI ® ArcScene ® environment, which is installed on each of the client nodes. The system is capable of all of the navigation functions offered in the ArcScene ® environment and it can be easily expanded to include more nodes and display tiles. The detailed implementation strategy and the latest visualization techniques are discussed in this paper.

Lessons learned from building and calibrating the ICWall, a stereo tiled display

AbstractImplementation of stereo tiled displays is a rather demanding task. In this article we want to share the lessons we have learned during the design and construction of the ICWall tiled display. This large display, used in a classroom setting, is a high‐resolution stereo tiled display (2 × 8 tiles), built from low‐cost commodity components. The overall image is produced by an array of projectors. When building such a system, a key challenge is to align the projector images. We describe our automated approach for alignment/calibration of the left‐ and right‐eye stereo images. We provide measurements that show accuracy of this procedure. We explain and compare two calibration approaches: a single‐pass and a two‐pass rendering method to align the tiled images. We explain how to provide seamless image on the tiled display and which issues have to be solved. We also discuss the depth perception issues on the ICWall for the large audiences. Another important aspect, is the architecture of the software used for PC‐cluster‐based rendering. We describe Aura, the parallel scene graph API that is used for rendering on our tiled display. Copyright © 2007 John Wiley & Sons, Ltd.

4.2: Self‐Calibrating Tiled Displays

AbstractThis paper presents seamless tiled displays via completely distributed network of projector‐camera systems that calibrates itself without any user intervention. This makes projection‐based tiled displays very easy to deploy and maintain. The decentralized calibration methodology presented to achieve this also enables advanced capabilities like scalability, reconfigurability and fault‐tolerance.

SimWall: a practical user-friendly stereo tiled display wall system

SimWall is a user-friendly, stereo tiled display wall system composed of 18 commodity projectors operated by a Linux graphics cluster. Collaborating together, these projectors work as a single logical display capable of giving a high-resolution show, large-scale, and passive stereo scene. In order to avoid tedious system setup and maintenance, software-based automatic geometry and photometric calibration are used. The software calibration is integrated to the system seamlessly by an on-card transform method and is transparent to users. To end-users, SimWall works just as a common PC, but provides super computing, rendering and displaying ability. In addition, SimWall has stereoscopic function that gives users a semi-immersive experience in polarized passive way. This paper presents system architecture, implementation, and other technical issues such as hardware constraints, projectors alignment, geometry and photometric calibration, implementation of passive stereo, and development of overall soft- ware environment.

Tiled stereo display system for immersive telemeeting

In this paper, we present an efficient tiled stereo display system for tangible meeting. For tangible meeting, it is important to provide immersive display with high resolution image to cover up the field of view and provide to the local user the same environment as that of remote site. To achieve these, a high resolution image needs to be transmitted for reconstruction of remote world, and it should be displayed using a tiled display. However, it is hard to transmit high resolution image in real time due to the limit of network bandwidth, and so we receive multiple images and reconstruct a remote world with received images in advance. Then, we update only a specific area where remote user exists by receiving low resolution image in realtime. We synthesize the transmitted image to the existing environmental map of remote world and display it as a stereo image. For this, we developed a new system which supports GPU based real time warping and blending, automatic feature extraction using machine vision technique.

Screen Calibration Techniques for Multi-Projector Tiled Display Wall

Multi-Projector tiled display wall is thought to be an effective technique to tackle the conflict between the increasing demands for super-resolution display and the resolution limitations of a single display equipment,but currently there lack of normal forms and normalized methods to support screen calibration with a high precision and high reliability.This paper tries to solve this problem with a new color calibration scheme.The main problems in screen calibration and the existing solutions are introduced first.Then the screen calibration process and geometry calibration methods are listed.After that,evaluation criterions for screen calibration are discussed,and a generalized color model for projectors color calibration and a visual seamlessness algorithm are presented in detail. Only employing a digital camera,the new scheme can build tiled display walls with high-precision visual seamlessness,which results in higher construction efficiency and lower maintenance cost.The methods have been verified and applied in a variety of tiled display wall,and have shown great theoretical and practical significance for building and maintain tiled display walls.

The Perceptual Scalability of Visualization

Larger, higher resolution displays can be used to increase the scalability of information visualizations. But just how much can scalability increase using larger displays before hitting human perceptual or cognitive limits? Are the same visualization techniques that are good on a single monitor also the techniques that are best when they are scaled up using large, high-resolution displays? To answer these questions we performed a controlled experiment on user performance time, accuracy, and subjective workload when scaling up data quantity with different space-time-attribute visualizations using a large, tiled display. Twelve college students used small multiples, embedded bar matrices, and embedded time-series graphs either on a 2 megapixel (Mp) display or with data scaled up using a 32 Mp tiled display. Participants performed various overview and detail tasks on geospatially-referenced multidimensional time-series data. Results showed that current designs are perceptually scalable because they result in a decrease in task completion time when normalized per number of data attributes along with no decrease in accuracy. It appears that, for the visualizations selected for this study, the relative comparison between designs is generally consistent between display sizes. However, results also suggest that encoding is more important on a smaller display while spatial grouping is more important on a larger display. Some suggestions for designers are provided based on our experience designing visualizations for large displays.

초대형 해석 결과의 분석을 위한 고해상도 타일 가시화 시스템 개발

본 논문에서는 저가의 클러스터 컴퓨터 시스템과 저해상도 영상장비들을 이용하여 초대형 해석 데이터를 정밀하게 분석할 수 있는 고해상도 타일 가시화 시스템을 개발하였다. 타일 가시화 하드웨어 구축 시 유의점을 고찰하고, 화면왜곡 현상을 제거할 수 있는 빔프로젝터 위치조절장치를 설계/제작하였다. 타일 가시화 소프트웨어 개발에서 그래픽 사용자 인터페이스와 렌더링을 위해서는 Qt와 OpenGL 라이브러리를 이용하였다. 또한 LAM-MPI 라이브러리를 통해 각각의 클러스터 컴퓨터 노드로부터 얻게 되는 조각적인 화면들을 전체의 한 화면으로 동기화시켜 왜곡 없는 전체 타일 영상을 만들도록 하였다. In this paper, a tiled display system is developed to get a high-resolution image in visualization of large-scale structural analysis data with low-resolution display devices and low-cost cluster computer system. Concerning the hardware system, some of the crucial points are investigated, and a new beam-projector positioner is designed and manufactured to resolve the keystone phenomena which result in distorted image. In the development of tiled display software, Qt and OpenGL are utilized for GUI and rendering, respectively. To obtain the entire tiled image, LAM-MPI is utilized to synchronize the several sub-images produced from each cluster computer node.

Photometric and Chromatic Calibration for Multi-Projector Tiled Displays

Photometric and Chromatic Calibration for Multi-Projector Tiled Displays

The VarrierTMautostereoscopic virtual reality display

Virtual reality (VR) has long been hampered by the gear needed to make the experience possible; specifically, stereo glasses and tracking devices. Autostereoscopic display devices are gaining popularity by freeing the user from stereo glasses, however few qualify as VR displays. The Electronic Visualization Laboratory (EVL) at the University of Illinois at Chicago (UIC) has designed and produced a large scale, high resolution head-tracked barrier-strip autostereoscopic display system that produces a VR immersive experience without requiring the user to wear any encumbrances. The resulting system, called Varrier, is a passive parallax barrier 35-panel tiled display that produces a wide field of view, head-tracked VR experience. This paper presents background material related to parallax barrier autostereoscopy, provides system configuration and construction details, examines Varrier interleaving algorithms used to produce the stereo images, introduces calibration and testing, and discusses the camera-based tracking subsystem.

Modeling Color Properties of Tiled Displays

Abstract The concept of tiled displays can be successful only if such displays are made to look like a single display perceptually. The two issues that need to be solved to achieve this goal are geometric correction and color seamlessness of images spanning across tiles. Geometric correction algorithms borrow pin‐hole camera models to model projector display geometry. In this paper, we introduce an abstract modeling function that describes the color seen by a viewer when displayed by a display device. Though this function can be used to model color displayed by any common display device, in this paper, we use it to model color in multiprojector display systems. We use the model to explain the reasons for different types of color variations in a multiprojector display, to compare different color correction algorithms, and to derive such algorithms directly from the model.

59.5L: Late‐News Paper: A 68‐inch SVGA 4×4 Tiled Display

AbstractIn this paper, we describe recent advances in the production and performance of a seamless tiled display technology. A new automated method to produce arrays of optical light guides has been implemented in the development of a 68‐inch 16‐tile SVGA (800×600) display.