Publications

Additional information about our display technology can be found in the following selected publications.

2006

D. Cotting and M. Gross,
Interactive Environment-Aware Display Bubbles,
Proc. of ACM UIST 2006,
ACM Press, pp. 245-254.

We present a novel display metaphor which extends traditional tabletop projections in collaborative environments by introducing freeform, environment-aware display representations and a matching set of interaction schemes. For that purpose, we map personalized widgets or ordinary computer applications that have been designed for a conventional, rectangular layout into space-efficient bubbles whose warping is performed with a potential-based physics approach. With a set of interaction operators based on laser pointer tracking, these freeform displays can be transformed and elastically deformed using focus and context visualization techniques. We also provide operations for intuitive instantiation of bubbles, cloning, cut & pasting, deletion and grouping in an interactive way, and we allow for user-drawn annotations and text entry using a projected keyboard. Additionally, an optional environment-aware adaptivity of the displays is achieved by imperceptible, realtime scanning of the projection geometry. Subsequently, collision-responses of the bubbles with non-optimal surface parts are computed in a rigid body simulation. The extraction of the projection surface properties runs concurrently with the main application of the system. Our approach is entirely based on off-the-shelf, low-cost hardware including DLP-projectors and FireWire cameras.

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2005

D. Cotting, R. Ziegler, M. Gross, and H. Fuchs,
Adaptive Instant Displays: Continuously Calibrated Projections Using Per-Pixel Light Control,
Proc. of Eurographics 2005,
Eurographics Association, pp. 705-714.

We present a framework for achieving user-defined on-demand displays in setups containing bricks of movable cameras and DLP-projectors. A dynamic calibration procedure is introduced, which handles cameras and projectors in a unified way and allows continuous flexible setup changes, while seamless projection alignment and blending is performed simultaneously. For interaction, an intuitive laser pointer based technique is developed, which can be combined with real-time 3D information acquired from the scene. All these tasks can be performed concurrently with the display of a user-chosen application in a non-disturbing way. This is achieved by using an imperceptible structured light approach enabling pixel-based surface light control suited for a wide range of computer graphics and vision algorithms. To ensure scalability of light control in the same working space, multiple projectors are multiplexed.

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Presentation
Movie

D. Cotting, M. Naef, M. Gross, and H. Fuchs,
Imperceptible Patterns for Reliable Acquisition of Mixed Reality Environments,
Proc. of Intl. Workshop on Image Analysis for Multimedia Interactive Services 2005.

Projection-based mixed and augmented reality settings often require concurrent optical camera acquisition. Unfortunately, the grabbed images frequently capture the projected imagery in addition to the desired scenery, introducing undesired interference and complicating image analysis. To efficiently improve signal-to-noise ratio, we present a method allowing the acquisition to take place under controlled illumination conditions. By exploiting the micro-mirror modulation pattern used by Digital Light Processing (DLP) projectors, a pixel-level control of light can be achieved. Since the patterns are imperceptible to the human eye and only slightly degrade the projected images, structured light techniques are introduced into humaninhabited mixed and augmented reality environments, where they often were too intrusive previously. This extended abstract gives an overview of the proposed embedding and illustrates feasibility and usefulness of the approach with representative example applications.

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Presentation


2004
D. Cotting, M. Naef, M. Gross, and H. Fuchs, Embedding Imperceptible Patterns into Projected Images for Simultaneous Acquisition and Display, Proc. of IEEE/ACM International Symposium on Mixed and Augmented Reality 2004, IEEE Computer Society Press, pp. 100-109.

We introduce a method to imperceptibly embed arbitrary binary patterns into ordinary color images displayed by unmodified off-the-shelf Digital Light Processing (DLP) projectors. The encoded images are visible only to cameras synchronized with the projectors and exposed for a short interval, while the original images appear only minimally degraded to the human eye. To achieve this goal, we analyze and exploit the micro-mirror modulation pattern used by the projection technology to generate intensity levels for each pixel and color channel. Our real-time embedding process maps the user’s original color image values to the nearest values whose camera-perceived intensities are the ones desired by the binary image to be embedded. The color differences caused by this mapping process are compensated by error-diffusion dithering. The non-intrusive nature of our novel approach allows simultaneous (immersive) display and acquisition under controlled lighting conditions, as defined on a pixel level by the binary patterns. We therefore introduce structured light techniques into human-inhabited mixed and augmented reality environments, where they previously often were too intrusive.

Paper
Presentation
Movie