Automatically Reconfigurable Arrays of Projectors for Wide-Area Display

Principal Investigator: Henry Fuchs
Funding Agencies: Lawrence Livermore National Laboratories / University of California
Agency Number: B504967

Abstract
The goal of this project is to develop a dynamically reconfigurable multi-projector display system. We envision a system composed of ceiling-mounted projectors, each with computer-controlled pan, tilt and zoom adjustments and a set of cameras for closed-loop system calibration and control. Such a system offers 1) automatic reconfigurability for different area, resolution and brightness tradeoffs, 2) rendering performance without degradation under a variety of configurations, and 3) straight-forward realization from off-the-shelf components. Such a reconfigurable system would allow users, for example, to transition easily between wide-area, multi-wall display for group "slide" presentations, and a higher-resolution, brighter, single-wall display for 3D scientific visualization. Current wide-area rear-projector display systems require tedious mechanical alignment, are rarely reconfigurable, and typically require substantial structural modifications for the projector optical path behind the display surface.

The proposed system is composed of many individually controlled light projectors, the collection of which functions as a single logical display. Using front projection, the light projectors tile the display surface at any desired zoom scale in a configuration that can be completely controlled by the user. For a particular selection of zoom settings and projector locations, the system automatically calibrates and displays graphical data. Specifically, we will emphasize configurations where many projectors cover a wall in an array at very high pixel resolutions. Within this paradigm we can implement displays with high-resolution insets.

We will address the four core technical problems of calibration, reconfigurability, rendering performance, and construction from off-the-shelf hardware. We will implement solutions to these technical tasks and evaluate their performance as the system is constructed. We will accomplish the calibration of the reconfigurable system via cameras that observe the projected display and adjust the representation of the display environment accordingly. The system will reconfigure itself via serial-line control of zoom and mirror-based control of the direction of projection. The algorithms for rendering that we develop will display imagery with the calibrated set of projectors, making the overall display visually seamless and achieving performance similar to that of a single projector. The final system will be constructed from off the-shelf hardware,making the prototype that we will demonstrate easily reproducible at other sites.