摘要
随着科学技术的高速发展以及信息量的急速膨胀,在大规模信息可视化、虚拟现实和仿真、数字影院、展览展示、会议及教育等诸多领域,人们对显示技术的要求越来越高。主要需求表现为高的分辨率、大的显示尺寸和强的沉浸感。由于单台投影仪支持分辨率有限,对多台投影仪输出画面进行拼接来构建多投影显示系统已经成为一个备受关注的研究热点。
目前多投影显示系统根据实现方式可分为硬件实现和软件实现。专业硬件产品处理能力强,系统可伸缩性好,但往往针对一种应用场合,价格不菲。国内外研究小组开发的多投影显示系统在非专业硬件基础上利用软件实现各种功能,例如几何和颜色校正,边缘融合,远程交互等。软件实现往往系统功能丰富,价格低廉。目前,基于专业硬件的多投影系统的主要问题为:对于VGA模拟信号,系统缺乏对VGA采集信号进行高质量的颜色校正,难以消除多投影拼接画面色度和亮度的不一致;缺乏对每类应用进行灵活配置,多配置间难以动态切换;当系统输入信号种类较多,每类包含大量的信号采集窗口时,现有系统未提供面向任务的多窗口管理机制。
本文给出了一套基于多窗口管理的多投影显示系统。与现有基于专业硬件的多投影系统相比,本文系统具有如下优势:
●利用软件方式实现系统的各种功能,扩展性较好,且系统采用非专业硬件,系统成本较专业硬件产品价格低。
●内置多个处理模块,能对采集得到的信号数据进行相关处理。模块与模块之间能自由组合成处理流水线。另外,能动态管理信号处理所需参数,对同一类型参数提供多套配置,并能在多配置之间动态切换。
●提供类似于Windows的系统桌面和任务栏,用户通过简单的鼠标操作即可实现复杂的布局管理。提供应用场合配置管理功能,支持多个应用场合以及应用场合之间的动态切换。
实验数据和实际应用表明本文系统能在主流硬件环境下实现对各类外接信号源的实时捕获,在大部分应用场合下绘制达到实时水平。面向任务的多窗口控制端简化了用户操作,提高了系统的可用性。
With rapid development of science and technology and explosion of information, user requirements of display technology are also getting higher and higher, especially in fields of large-scale information visualization, virtual reality and emulation,digital cinema, exhibition industry, conference and education,etc.And main requirements are on high resolution, large display area and deep immersion. Due to the limitations of display size and computing resource, single channel is hard to meet the requirements of massive information visualization, so using several projectors to construct multi-projector display system is becoming much more popular.
Current multi-projector display systems can be divided into two categories in terms of their realization manner:the hardware manner and the software manner. Professional hardware products have powerful processing ability, and they are very flexible.However, they are designed for only one application, and they are very expensive.Multi-projector display systems developed by research teams both home and abroad are realized in software manner. They provide a rich set of features, e.g., geometry and color calibration, edge blending, remote control and only use non-professional hardwares.In contrast to hardware realization,software realization can provide more features at a relatively lower price.Currently, the limitations of hardware realization are:for non-overlapped VGA analog signals, existing systems don't support high-quality color calibration to solve chrominance variation and luminance nonuniformity; existing systems don't support flexible profile management for multiple applications and cannot switch among them at runtime; when there are many input signals, and for each input signal, there are a number of windows, existing systems don't support task-oriented multi-window management.
This thesis provided a system called multi-window-management-based multi-projector display system.In contrast to existing display systems based on professional hardwares, the advantages are:
●Provide system features in software realization manner with good scalability. Due to the using of non-professional hardwares, the cost is relatively lower than professional hardware products.
●Provide a large set of signal processing modules, which can be combined with each other freely into pipelines with different processing functions. What's more, support flexible profile management for processing parameters.For each type of signal, support multiple parameter profiles and runtime switching among them.
●Provide desktop manager and taskbar similar with Windows. So that users can easily manage complex windows layout by interacting with the interface. Support profile management for multiple applications, and can switch application profiles at runtime.
Experiment results and practical applications have shown that our system can capture various signals in real time, and reach real-time rendering for most applications.And task-oriented multi-window remote controller simplifies user interactions, making system easier to use.
引文
[AG06]Access Grid.http://www.accessgrid.org/[R/OL].Last accessed on May,2010.
[Alimo07]ALIMOHIDEEN J.Design and implementation of SAGE display controller[D].Thesis Project for Master of Science in Computer Science 2007.
[Ball05]BALL R, NORTH C. Analysis of user behavior on high-resolution tiled displays[A].In:INTERACT 2005,2005:350-363.
[Bern08]BERNSTEIN M,SHRAGER J, WINOGRAD T. Taskpose-Exploring Fluid Boundaries in an Associative Window Visualization[A].In: Proceedings of UIST[C].2008:231-234.
[Chen01]CHEN H, CLARK D W, LIU Z, et al. Software environments for cluster-based display systems[A].In:IEEE/ACM International Symposium on Cluster Computing and the Grid[C].2001.
[Chen02]CHEN H, SUKTHANKAR R et al.Scalable Alignment of Large-Format Multi-Projector Displays Using Camera Homography Trees[A].In: Proceedings of IEEE Visualization.2002:339-346.
[Debevec97] DEBEVEC P, and MALIK J.Recovering high dynamic range radiance maps from photographs[A].In:Proceedings of SIGGRAPH[C].1997: 369-378.
[Expose10]Apple Computer Expose, Inc.http://www.apple.com.Last accessed on May,2010.
[Gvitech10] Gvitech FreeWindow多视窗无缝显示系统.http://www.gvitech.c om/gvi/cn/products2.asp?id=2[R/OL].Last accessed on May,20 10.
[Hender86]HENDERSON DA, CARD S. Rooms:The use of multiple virtual workspaces to reduce space contention in a window-based graphical user interface[J].ACM Transactions on Graphics.vol.5,no. 3,1986:211-243.
[Hereld00]HERELD M, JUDSON I R, STEVENS R L. Introduction to building projection-based tiled display systems[J].IEEE Computer Graphics and Applications.vol.20,2000:22-28.
[Hump02]HUMPHREYS G, HOUSTON M, NG R et al. Chormium:a stream-processing framework for interactive rendering on clusters[A].In Proceddings of the 29th Annual Conference Computer Graphics and Interactive Techniques[C].2002:693-702.
[Jeong06]JEONG B, RENAMBOT L, JAGODIC R, et al.High-performance dynamic graphics streaming for scalable adaptive graphics environment[A].In:ACM/IEEE Supercomputing[C].Nov,2006.
[Jeong07]JEONG B. Collaborative Visualization Architecture in Scalable Adaptive Graphics Environment[A].In:IBM Visualization and Graphics Student Symposium,TJ Watson Research-Hawthorne and Yorktown,New York:2007.
[Jiang07a]JIANG Z, LUO X, MAO Y, et al.Interactive browsing of large images on multi-projector display wall system[A].In:12th International Conference on Human-Computer Interaction[C].LNCS, vol.4551, 2007:827-836.
[Jiang07b]JIANG Z, MAO Y, QIN B, et al.A multi-projector display wall system for windows desktop applications[J].Journal of Computational Information System.2007.
[Jiang07c]JIANG Z, MAO Y, QIN B, et al.A high resolution video display system by seamlessly tiling multiple projectors[A].In:IEEE International Conference on Multimedia and Expo[C].2007:2070-2073.
[Jiang07d]JIANG Z, JIANG N, MAO Y, et al.A multi-projector display wall system driven by chromium framework on PC cluster[A].In: Proceedings of 12th International Conference on Human-Computer Interaction[J],2007.
[Kapte03]KAPTELININ V. UMEA:Translating interaction histories into project contexts[A].In:Proceedings of CHI[C].2003:353-360.
[Kim05]KIM JaeYoun, KIM JongWon.Decomposable decoding and display structure for scalable media visulization over advanced coolaborative environments[J].SPIE ITCOM'2005:Multimedia Systems and Applications Ⅷ,vol.6195,2005:458-466.
[Leigh08]LEIGH J, BROWN M D. Cyber-commons:merging real and virtual worlds[J].Commnications of the ACM.vol 51,no.1,2008:82-85.
[Li00]LI K,CHEN H, CHEN Y, et al. Eearly experiences and challenges in building and using a scalable display wall system[J].IEEE Computer Graphics and Applications,vol 20,2000:29-37.
[Li05]LI K, HIBBS M, WALLANCE G et al.Dynamic scalable visualization for collaborative scientific applications[A].In:Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium[C].Apr.2005.
[Ni06]NI T, SCHMIDT G S, STAADT O G, et al. A survey of large high-resolution display technologies, techniques, and applications[A].In:Proceedings of IEEE Virtual Reality[C].Mar. 2006:223-236.
[Oliver06a]OLIVER N,SMITH G et al.SWISH:Semantic analysis of window titles and switching history[A].In:Proceedings of IUI[C].2006:194-201.
[Oliver06b] OLIVER N, CZERWINSKI M et al.RelAltTab:Assisting users in switching windows[A].In:Proceedings of IUI[C].2006:385-388.
[Raij03]RAIJ A, GILL G, MAJUMDER A, et al.PixelFlex2:a comprehensive, automatic, casually-aligned multi-projector display[A].In: Proceedings of PCS[C].2003:203-211.
[Rober04]ROBERTSON G, HORVITZ E et al.Scalable Fabric:Flexible Task Management[A].In:Proceedings of AVI[C].2004:85-89.
[Rober05]ROBERTSON G, CZERWINSKI M, BAUDISH P et al.The large-display user experience[J].IEEE Computer Graphics and Applications,vol. 25,no 4,2005:44-51.
[Singh04]SINGH R, JEONG B, RENAMBOT L, et al.TeraVision:a distributed, scalable, high resolution graphics streaming system[A].In: Proceedings of IEEE Cluster[C].2004.
[Smith03]SMITH G, BAUDISCH P, ROBERTSON G et al.GroupBar:The TaskBar Evolved[A].In:Proceedings of OZCHI[C].2003:34-43.
[Sony08]Sony SXRD Projector. http://www.sony.com/[R/OL].Last accessed on May,2010.
[Standford01] Interactive Workspace.http://iwork.stanford.edu/[R/OL].Last accessed on May,2010.
[Stumpf05]STUMPF S, BAO X et al.Predicting user tasks:I know what you're doing![A].In:Proceedings of AAAI[C].2005.
[Tash06]TASHMAN C. WindowScape:A Task Oriented Window Manager[A]. In:Proceedings of UIST[C].2006:77-80.
[Wallace03] WALLACE G, CHEN H, LI K. Color gamut matching for tiled display walls[A].In:Proceedings of IPTS[C].2003:293-302.
[3DP10]3D Perception.http://www.gvitech.com/gvi/cn/products2.asp?id =2[R/OL].Last accessed on May,2010.
[何07]何跃明.多投影大屏幕系统的自动构建方法[D].杭州:浙江大学,2007.
[华图科技10]华图科技China Graphics.http://www.chinagraphics.com/type.a sp?pid=221&tit=zzcp&cateID=276&ParentStr=|221|&name=%A2% F1%2E%CD%BC%CF%F1%B4%A6%CO%ED%C6%F7[R/OL].Last acc essed on May,2010.
[林03]林柏伟.PC架构的多投影面沉浸式虚拟环境及其应用[D].杭州:浙江大学,2003.
[陶08]陶俊仪.面向多通道输出系统的远程交互显示技术[D].上海:复旦大学,2008.
[王07]王修晖,华炜,林海等.面向多投影显示墙的画面校正技术[J].软件学报,vol.18,no.11,2007:2955-2964.
[张09]张磊.基于视频捕获卡的多投影显示系统[D].上海:复旦大学,2009.