{Related Work: With Abstracts}

Ahrens, J. P., K. Li, et al. (2000). Next-Generation Visualization Displays: The Research Challenges of Building Tiled Displays (panel session). Visualization, Salt Lake City, UT, IEEE.

Alphonse, G. A. and J. Lubin (1992). Psychophysical Requirements for Tiled Large Screen Displays. High-Resolution Displays and Project Systems, San Jose, CA, USA, SPIE.
The types of flaws susceptible to affect image quality in tiled displays are identified, and psychophysical thresholds for their detectability are prescribed. Bright seams are not tolerable, and completely dark seams have a threshold of 3.5 arcsec. Tile luminosity variability threshold is less than 1% in some instances. Chromaticity variabilities must be kept well below 1% for one jnd discrimination in certain regions of the spectrum, and vernier misalignments must be about 5 arcsec. Despite these stringent requirements, tiling remains a viable way of making large displays.

Ashdown, M. and P. Robinson (2004). A Personal Projected Display. MultiMedia, New York, NY, ACM.
User interfaces using windows, keyboard and mouse have been in use for over 30 years, but only offer limited facilities to the user. Conventional displays are small, at least compared with a physical desk; conventional input devices restrict both manual expression and cognitive flexibility; remote collaboration is a poor shadow of sitting in the same room. We show how recent technological advances in large display devices and input devices can address these problems. The Escritoire is a desk-based interface using overlapping projectors to create a large display with a high resolution region in the centre for detailed work. Two pens provide bimanual input over the entire area, and an interface like physical paper addresses some of the affordances not provided by the conventional user interface. Multiple desks can be connected to allow remote collaboration. The system has been tested with single users and collaborating pairs.

Ashdown, M., K. Oka, et al. (2005). Combining Head Tracking and Mouse Input for a GUI on Multiple Monitors. CHI, Portland, OR, ACM.
The use of multiple LCD monitors is becoming popular as prices are reduced, but this creates problems for window management and switching between applications. For a single monitor, eye tracking can be combined with the mouse to reduce the amount of mouse movement, but with several monitors the head is moved through a large range of positions and angles which makes eye tracking difficult. We thus use head tracking to switch the mouse pointer between monitors and use the mouse to move within each monitor. In our experiment users required significantly less mouse movement with the tracking system, and preferred using it, although task time actually increased. A graphical prompt (flashing star) prevented the user losing the pointer when switching monitors. We present discussions on our results and ideas for further developments.

Ball, R. and C. North (2005). Effects of Tiled High-Resolution Display on Basic Visualization and Navigation Tasks. CHI, Portland, Oregon, ACM.
Large high-resolution screens are becoming increasingly available and less expensive. This creates potential advantages for data visualization in that more dense data and fine details are viewable at once. Also, less navigation may be needed to see more data. However, little work has been done to determine the effectiveness of large high-resolution displays, especially for basic low-level data visualization and navigation tasks. This paper describes an exploratory study on the effects of a large tiled display with a resolution of 3840x3072 as compared to two smaller displays (1560x2048 and 1280x1024). We conclude that, with finely detailed data, higher resolution displays that use physical navigation significantly outperform smaller displays that use pan and zoom navigation. Qualitatively, we also conclude that use of the larger display is less stressful and creates a better sense of confidence than the smaller displays.

Baudisch, P., N. Good, et al. (2002). Keeping Things in Context: A Comparative Evaluation of Focus Plus Context Screens, Overviews, and Zooming. CHI, Minneapolis, Minnesota, USA, ACM.
Users working with documents that are too large and detailed to fit on the user's screen (e.g. chip designs) have the choice between zooming or applying appropriate visualization techniques. In this paper, we present a comparison of three such techniques. The first, focus plus context screens, are wall-size low-resolution displays with an embedded high-resolution display region. This technique is compared with overview plus detail and zooming/panning. We interviewed fourteen visual surveillance and design professionals from different areas (graphic design, chip design, air traffic control, etc.) in order to create a representative sample of tasks to be used in two experimental comparison studies. In the first experiment, subjects using focus plus context screens to extract information from large static documents completed the two experimental tasks on average 21% and 36% faster than when they used the other interfaces. In the second experiment, focus plus context screens allowed subjects to reduce their error rate in a driving simulation to less than one third of the error rate of the competing overview plus detail setup.

Baudisch, P., E. Cutrell, et al. (2003). Drag- and -Pop and Drag- and -Pick: Techniques for Accessing Remote Screen Content on Touch- and Pen- operated Systems. INTERACT.
Abstract: Drag-and-pop and drag-and-pick are interaction techniques designed for users of pen- and touch- operated display systems. They provide users with access to screen content that would otherwise be impossible or hard to reach, e.g., because it is located behind a bezel or far away from the user. Drag-and-pop is an extension of traditional drag-and-drop. As the user starts dragging an icon towards some target icon, drag-and-pop responds by temporarily moving potential target icons towards the user’s current cursor location, thereby allowing the user to interact with these icons using comparably small hand movements. Drag-and-Pick extends the drag-and-pop interaction style such that it allows activating icons, e.g., to open folders or launch applications. In this paper, we report the results of a user study comparing drag-and-pop with traditional drag-and-drop on a 15’ (4.50m) wide interactive display wall. Participants where able to file icons up to 3.7 times faster when using the drag-and-pop interface.

Baudisch, P., E. Cutrell, et al. (2004). Mouse Ether: Accelerating the Acquisition of Targets Across Multi-Monitor Displays. CHI, Vienna, Austria, ACM.
When acquiring a target located on a different screen, multi-monitor users face a challenge: differences in resolution and vertical and horizontal offsets between screens cause the mouse pointer to get warped, making the attempt to acquire the target difficult. Mouse ether eliminates warping effects by applying appropriate transformations to all mouse move events. In our user study, mouse ether improved participants' performance on a target acquisition task across two screens running at different resolutions by up to 28%. 7 of the 8 participants also strongly preferred using mouse ether to the control.

Benko, H. and S. Feiner (2005). Multi-Monitor Mouse. CHI, Portland, OR, ACM.
Multiple-monitor computer configurations significantly increase the distances that users must traverse with the mouse when interacting with existing applications, resulting in increased time and effort. We introduce the Multi-Monitor Mouse (M3) technique, which virtually simulates having one mouse pointer per monitor when using a single physical mouse device. M3 allows for conventional control of the mouse within each monitor's screen, while permitting immediate warping across monitors when desired to increase mouse traversal speed. We report the results of a user study in which we compared three implementations of M3 and two cursor placement strategies. Our results suggest that using M3 significantly increases interaction speed in a multi-monitor environment. All eight study participants strongly preferred M3 to the regular mouse behavior.

Cartwright, W. (1997). "New Media and Their Application to the Production of Map Products." Computers & Geosciences 23(4): 447-456.
The use of animations, multimedia and computer graphics is now commonplace in the spatial sciences. Usually users are required only to have access to sophisticated and powerful computer equipment and peripherals to use effectively such contemporary offerings. The range of electronic displays used for spatial information visualization can be enlarged through the application of other available devices, from domestic televisions to Internet services, making it possible to access spatial information in ways and with equipment that is familiar. However, many users, may be unable to comprehend the real information being displayed with these new tools due to a lack of "ground truthing". "Ground truthing" in this context refers to additional data and information that ensure that the user, especially the novice appreciates that depicted phenomena are real and do occur at some actual location at some point of time. "Ground truthing" of the depiction of spatial information nay be achieved by linking electronic map displays to "real" locations through the use of the Internet and the World Wide Web. This paper gives an overview of the various types of products that could be developed for the delivery of spatial information in a different manner that complements the methods now in popular use and proposes the use of projects on CD-ROM and the World Wide Web that could be linked to mapping displays to provide "electronic ground truthing".

Czerwinski, M., D. S. Tan, et al. (2002). Women Take a Wider View. CHI, Minneapolis, MN, ACM.
Published reports suggest that males significantly outperform females in navigating virtual environments. A novel navigation technique reported in CHI 2001, when combined with a large display and wide field of view, appeared to reduce that gender bias. That work has been extended with two navigation studies in order to understand the finding under carefully controlled conditions. The first study replicated the finding that a wide field of view coupled with a large display benefits both male and female users and reduces gender bias. The second study suggested that wide fields of view on a large display were useful to females despite a more densely populated virtual world. Implications for design of virtual worlds and large displays are discussed. Specifically, women take a wider field of view to achieve similar virtual environment navigation performance to men.

Czerwinski, M., G. Smith, et al. (2003). Toward Characterizing the Productivity Benefits of Very Large Displays. INTERACT.
Larger display surfaces are becoming increasingly available due to multi-monitor capability built into many systems, in addition to the rapid decrease in their costs. However, little is known about the performance benefits of using these larger surfaces compared to traditional single-monitor displays. In addition, it is not clear that current software designs and interaction techniques have been properly tuned for these larger surfaces. A preliminary user study was carried out to provide some initial evidence about the benefits of large versus small display surfaces for complex, multi-application office work. Significant benefits were observed in the use of a prototype, larger display, in addition to significant positive user preference and satisfaction with its use over a small display. In addition, design guidelines for enhancing user interaction across large display surfaces were identified. User productivity could be significantly enhanced in future graphical user interface designs if
developed with these findings in mind.

Eick, S. G. and A. F. Karr (2002). "Visual Scalability." Journal of Computational & Graphical Statistics 11(1): 22-43.
Visual scalability is the capability of visualization tools effectively to display large datasets, in terms of either the number or the dimension of individual data elements. This article defines and structures the problem of visual scalability, with special emphasis on the role of visualization as a means of access to details of the data. This is done abstractly in terms of responses that measure the business or scientific impact of visualizations and factors that affect the responses, and concretely in terms of measures of visual scalability and factors inuencing them. We assess both current capabilities and future prospects along a number of dimensions. Our approach for increasing visual scalability includes improved visual metaphors, interactivity and perspectives that link multiple views.

Funkhouser, T. and K. Li (2000). "Onto the Wall: Large Displays." Special issue of Computer Graphics and Applications 20(4).

Guimbretiere, F., M. Stone, et al. (2001). Fluit Interaction with High-resolution Wall-size Displays. UIST, Orlando, FL, ACM.
This paper describes new interaction techniques for direct pen-based interaction on the Interactive Mural, a large (6'x3.5') high resolution (64 dpi) display. They have been tested in a digital brainstorming tool that has been used by groups of professional product designers. Our "interactive
wall" metaphor for interaction has been guided by several goals: to support both free-hand sketching and high-resolution materials, such as images, 3D models and GUI application windows; to present a visual appearance that does not clutter the content with control devices; and to support fluid interaction, which minimizes the amount of attention demanded and interruption due to the mechanics of the interface. We have adapted and extended techniques that were developed for electronic whiteboards and generalized the use of the FlowMenu to execute a wide variety of actions in a single pen stroke, While these techniques were designed for a brainstorming tool, they are very general and can be used in a wide variety of application domains using interactive surfaces.

Humphreys, G. and P. Hanrahan (1999). A Distributed Graphics System for Large Tiled Displays. Visualization, San Francisco, CA, IEEE.
Recent interest in large displays has led to renewed development of tiled displays, which are comprised of several individual displays arranged in an array and used as one large logical display. Stanford's “Interactive Mural” is an example of such a display, using an overlapping four by two array of projectors that back-project onto a diffuse screen to form a 6' by 2' display area with a resolution of over 60 dpi. Writing software to make effective use of the large display space is a challenge because normal window system interaction metaphors break down. One promising approach is to switch to immersive applications; another approach, the one we are investigating, is to emulate office, conference room or studio environments which use the space to display a collection of visual material to support group activities.In this paper we describe a virtual graphics system that is designed to support multiple simultaneous rendering streams from both local and remote sites. The system abstracts the physical number of computers, graphics subsystems and projectors used to create the display. We provide performance measurements to show that the system scales well and thus supports a variety of different hardware configurations. The system is also interesting because it uses transparent “layers,” instead of windows, to manage the screen.

Humphreys, G., M. Eldridge, et al. (2001). WireGL: A Scalable Graphics System for Clusters. Computer Graphics and Interactive Techniques, ACM.
We describe WireGL, a system for scalable interactive rendering on a cluster of workstations. WireGL provides the familiar OpenGL API to each node in a cluster, virtualizing multiple graphics accelerators into a sort-first parallel renderer with a parallel interface. We also describe techniques for reassembling an output image from a set of tiles distributed over a cluster. Using flexible display management, WireGL can drive a variety of output devices, from standalone displays to tiled display walls. By combining the power of virtual graphics, the familiarity and ordered semantics of OpenGL, and the scalability of clusters, we are able to create time-varying visualizations that sustain rendering performance over 70,000,000 triangles per second at interactive refresh rates using 16 compute nodes and 16 rendering nodes.

Humphreys, G., M. Houston, et al. (2002). Chromium: A Stream-Processing Framework for Interactive Rendering on Clusters. Computer Graphics and Interactive Techniques, San Antonio, Texas, ACM.
We describe Chromium, a system for manipulating streams of graphics API commands on clusters of workstations. Chromium's stream filters can be arranged to create sort-first and sort-last parallel graphics architectures that, in many cases, support the same applications while using only commodity graphics accelerators. In addition, these stream filters can be extended programmatically, allowing the user to customize the stream transformations performed by nodes in a cluster. Because our stream processing mechanism is completely general, any cluster-parallel rendering algorithm can be either implemented on top of or embedded in Chromium. In this paper, we give examples of real-world applications that use Chromium to achieve good scalability on clusters of workstations, and describe other potential uses of this stream processing technology. By completely abstracting the underlying graphics architecture, network topology, and API command processing semantics, we allow a variety of applications to run in different environments.

Jedrysik, P. A., J. A. Moore, et al. (2000). Interactive Displays for Command and Control. Aerospace, Big Sky, MT, USA, IEEE.
(Abstract from related pdf: The Interactive DataWall) The increasingly complex battlefield environment drives the requirement for the presentation and interactive control of the endless stream of information arriving from a diverse collection of sensors deployed on a variety of platforms. At best, the situational awareness picture is fragmented without the benefit of data fusion and correlation to present a true picture of the battlespace from all information sources. Collaboration and interaction is also needed for operators within a control center and among remote geographic locations. The need to display and manipulate real-time multimedia data in a battlefield operations control center is critical to the Joint Commander directing air, land, naval and space assets. The Interactive DataWall being developed by the Advanced Displays and Intelligent Interfaces (ADII) technology team of the Information Directorate of the Air Force Research Laboratory (AFRL/IF) in Rome, New York is a strong contender for solving the information management problems facing the 21st century military commander. It provides an ultra high-resolution large screen display with wireless interaction. Commercial off-the-shelf technology has been combined with specialized hardware and software developed in-house to provide a unique capability for multimedia data display and control.

Khan, A., G. Fitzmaurice, et al. (2004). A Remote Control Interface for Large Displays. UIST, Sante Fe, NM, ACM.
We describe a new widget and interaction technique, known as a "Frisbee," for interacting with areas of a large display that are difficult or impossible to access directly. A frisbee is simply a portal to another part of the display. It consists of a local "telescope" and a remote "target". The remote data surrounded by the target is drawn in the telescope and interactions performed within it are applied on the remote data. In this paper we define the behavior of frisbees, show unique affordances of the widget, and discuss design characteristics. We have implemented a test application and report on an experiment that shows the benefit of using the frisbee on a large display. Our results suggest that the frisbee is preferred over walking back and forth to the local and remote spaces at a distance of 4.5 feet.

Mackinlay, J. D. and J. Heer (2004). Wideband Displays: Mitigating Multiple Monitor Seams. CHI, Vienna, Austria, ACM.
Wideband displays fill our field of view, creating new opportunities to develop effective visual interfaces. Although multiple monitors are becoming an affordable way to create wideband displays, the resulting seams create gaps in words and divide diagonal lines into nonaligned segments. We present several novel user interface techniques for creating seam-aware applications, showing that vendors need not wait for affordable seamless displays to exploit the potential of wideband displays.

Po, B. A., B. D. Fisher, et al. (2005). Comparing Cursor Orientations for Mouse, Pointer, and Pen Interaction. CHI, Portland, Oregon, ACM.
Most graphical user interfaces provide visual cursors to facilitate interaction with input devices such as mice, pointers, and pens. These cursors often include directional cues that could influence the stimulus-response compatibility of user input. We conducted a controlled evaluation of four cursor orientations and an orientation-neutral cursor in a circular menu selection task. Mouse interaction on a desktop, pointer (i.e. wand) interaction on a large screen, and pen interaction on a Tablet PC were evaluated. Our results suggest that choosing appropriate cursors is especially important for pointer interaction, but may be less important for mice or pens. Cursors oriented toward the lower-right corner of a display yielded the poorest performance overall while orientation-neutral cursors were generally the best. Advantages were found for orientations aligned with the direction of movement. We discuss these results and suggest guidelines for the appropriate use of cursors in various input and display configurations.

Sandstrom, T. A., C. Henze, et al. (2003). The Hyperwall. CMV, London, IEEE.
This paper describes the hyperwall, a visualization cluster that uses coordinated visualizations for interactive exploration of multidimensional data and simulations. The system strongly leverages the human eye-brain system with a generous 7x7 array of flat panel LCD screens powered by a Beowulf cluster. With each screen backed by a workstation class PC, graphic and compute intensive applications can be applied to a broad range of data in parallel. Navigational tools are presented that allow for investigation of high-dimensional data spaces.

Shedd, B. (2003). Exploding the Frame: Designing for Wall-Size Computer Displays. Information Visualization, IEEE.
High-resolution wall-size digital displays present significant new and different visual space to show and see imagery. I have been working with two wall-size digital displays at Princeton University for five years and directing and producing IMAX films for a decade, and I have noted some unique design considerations for creating effective visual images when they are spread across entire walls. I suggest these "frameless" screens -where images are so large we need to look around to see the entire field - need different ways of thinking about image design and visualization. Presenting such things as scale and detail take on new meaning when they can be displayed life-size and not shown in the context of one or many small frames such as we see everywhere. These design ideas will be of use for pervasive computing, interface research and design, interactive design, control design, representations of massive data sets, and creating effective displays of data for research and education.

Slocum, T. A., C. Blok, et al. (2001). "Cognitive and Usability Issues in Geovisualization." Cartography and Geographic Information Science 28(1): 61-75.
This article highlights the progression of visualizing geospatial data and the need for these to fit within a cognitive framework. Developments in hardware and software have led to (and will continue to stimulate) numerous novel methods for visualizing geospatial data. It is the authors’ belief that these novel methods will be of little use if they are not developed within a theoretical cognitive framework and iteratively tested using usability engineering principles. This article argues that cognitive and usability issues should be considered in the context of six major research themes: 1) geospatial virtual environments (GeoVEs); 2) dynamic representations (including animated and interactive maps); 3) metaphors and schemata in user interface design; 4) individual and group differences; 5) collaborative geovisualization; and 6) evaluating the effectiveness of geovisualization methods.

Staadt, O. G., J. Walker, et al. (2003). A Survey and Performance Analysis of Software Platforms for Interactive Cluster-Based Multi-Screen Rendering. Workshop on Virtual Environments, Zurich, Switzerland, ACM.
We present a survey of different software architectures designed to render on a tiled display. We provide an in-depth analysis of three selected systems, including their implementation of data distribution, sort-first rendering, and overall usability. We use various test cases to analyze the performance of these three systems.

Su, R. and B. P. Bailey (2005). Put Them Where? Towards Guidelines for Positioning Large Displays in Interactive Workspaces. INTERACT, Rome, Italy.
Multiple large displays are being increasingly used in interactive workspaces to enhance individual and group work. However, little research has
been conducted to determine whether various configurations of large displays impact users or their tasks differently. We show that such an impact exists, and take steps towards developing guidelines for how to effectively arrange large displays in interactive workspaces. For two large displays, we manipulated their physical separation, angle between them, and symmetry when facing each other and measured time on task, subjective workload, and satisfaction for application relocation tasks. From the results, we produced three useful guidelines: (i) displays
can be separated on a horizontal plane up to a subtended visual angle of 45, (ii) a display should not be placed behind a user, but if necessary, it should be offset relative to the user, and (iii) displays should be positioned at a 45 angle relative to each other rather than being orthogonal. As the use of large displays is increasing, these guidelines should have a broad, practical impact.

Swaminathan, K. and S. Sato (1997). "Interaction Design for Large Displays." Interactions 4(1): 15-24.
We think that large displays will become commonplace for home and office computers before the turn of the century. And interface design for large displays will require new ways of thinking about human-computer interaction. At Andersen Consulting’s Center for Strategic Technology Research, we recently built a demonstration prototype called Prairie that works with a display size of almost 6 feet by 3 feet and a resolution of 2400 by 1200 pixels (see Figure 1). In this paper, we use the Prairie system to illustrate many of the design issues that arise when designing for a large display.

Tan, D., D. Gergle, et al. (2003). With Similar Visual Angles, Larger Displays Improve Spatial Performance. CHI.
Large wall-sized displays are becoming prevalent. Although researchers have articulated qualitative benefits of group work on large displays, little work has been done to quantify the benefits for individual users. We ran two studies comparing the performance of users working on a large projected wall display to that of users working on a standard desktop monitor. In these studies, we held the visual angle constant by adjusting the viewing distance to each of the displays. Results from the first study indicate that although there was no significant difference in performance on a reading comprehension task, users performed about 26% better on a spatial orientation task done on the large display. Results from the second study suggest that the large display affords a greater sense of presence, allowing users to treat the spatial task as an egocentric rather than an exocentric rotation. We discuss future work to extend our findings and formulate design principles for computer interfaces and physical workspaces.

Tan, D. S. and M. Czerwinski (2003). Effects of Visual Separation and Physical Discontinuities when Distributing Information across Multiple Displays. INTERACT, IOS Press.
Systems that include multiple integrated displays distributed throughout the working environment are
becoming prevalent. Compared to traditional desktop displays, information presented on such systems is typically separated at much wider visual angles. Additionally, since displays are often placed at different depths or are framed by physical bezels, they introduce physical discontinuities in the presentation of information. In this paper, we describe a study that utilizes a divided attention paradigm to explore the effects of visual separation and physical discontinuities when distributing information across multiple displays. Results show reliable, though small, detrimental effects when information is separated within the visual field, but only when coupled with an offset in depth. Surprisingly, physical discontinuities such as monitor bezels and even separation in depth alone do not seem to affect performance on the set of tasks tested. Following the findings, we provide recommendations for the design of hardware and software in multiple display environments.

Tan, D., D. Gergle, et al. (2004). Physically Large Displays Improve Path Integration in 3D Virtual Navigation Tasks. CHI, Vienna, Austria, ACM.
Previous results have shown that users perform better on spatial orientation tasks involving static 2D scenes when working on physically large displays as compared to small ones. This was found to be true even when the displays presented the same images at equivalent visual angles. Further investigation has suggested that large displays may provide a greater sense of presence, which biases users into adopting more efficient strategies to perform tasks. In this work, we extend those findings, demonstrating that users are more effective at performing 3D virtual navigation tasks on large displays. We also show that even though interacting with the environment affects performance, effects induced by interactivity are independent of those induced by physical display size. Together, these findings allow us to derive guidelines for the design and presentation of interactive 3D environments on physically large displays.

Tse, E. and S. Greenberg (2004). Rapidly Prototyping Single Display Groupware throught the SDG Toolkit. Australasian User Interface, Dunedin, New Zealand, ACM.
Researchers in Single Display Groupware (SDG) explore how multiple users share a single display such as a computer monitor, a large wall display, or an electronic tabletop display. Yet today's personal computers are designed with the assumption that one person interacts with the display at a time. Thus researchers and programmers face considerable hurdles if they wish to develop SDG. Our solution is the SDGToolkit, a toolkit for rapidly prototyping SDG. SDGToolkit automatically captures and manages multiple mice and keyboards, and presents them to the programmer as uniquely identified input events relative to either the whole screen or a particular window. It transparently provides multiple cursors, one for each mouse. To handle orientation issues for tabletop displays (i.e., people seated across from one another), programmers can specify a participant's seating angle, which automatically rotates the cursor and translates input coordinates so the mouse behaves correctly. Finally, SDGToolkit provides an SDG-aware widget class layer that significantly eases how programmers create novel graphical components that recognize and respond to multiple inputs.

Wei, B., C. Silva, et al. (2000). "Visualization Research with Large Displays [analysis of communication networks and services]." Computer Graphics and Applications 20(4): 50-54.
We describe our research at AT&T Infolab on using large displays to interactively analyze and visualize AT&T's communication networks and services.

Yang, R., D. Gotz, et al. (2001). PixelFlex: A Reconfigurable Multi-Projector Display System. Visualization, San Diego, CA, IEEE.
This paper presents PixelFlex - a spatially reconfigurable multi-projector display system. The PixelFlex system is composed of ceiling-mounted projectors, each with computer-controlled pan, tilt, zoom and focus; and a camera for closed-loop calibration. Working collectively, these controllable projectors function as a single logical display capable of being easily modified into a variety of spatial formats of differing pixel density, size and shape. New layouts are automatically calibrated within minutes to generate the accurate warping and blending functions needed to produce seamless imagery across planar display surfaces, thus giving the user the flexibility to quickly create, save and restore multiple screen configurations. Overall, PixelFlex provides a new level of automatic reconfigurability and usage, departing from the static, one-size-fits-all design of traditional large format displays. As a front-projection system, PixelFlex can be installed in most environments with space constraints and requires little or no post-installation mechanical maintenance because of the closed-loop calibration.