Intensity Scaling Maps for Multi-Projector Display Calibration

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Solution Overview

Problem

Existing multi-projector display systems face challenges in achieving seamless alignment and brightness uniformity, particularly in bright environments, due to color and luminosity variance across projectors and geometric inconsistencies in the display surface, requiring complex and costly manual calibration methods.

Innovation Solution

The system generates intensity scaling maps for each projector to adjust pixel intensities based on distance from non-overlap regions, allowing for automated calibration and seamless composite projection across multiple projectors, reducing visible seams and brightness inconsistencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If manual calibration methods are used to align multiple projectors, then pixel and color alignment can be achieved, but the process becomes complex and time-consuming

Engineering Contradiction:

Improvepixel alignment precisionVSAvoidcalibration time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The system performs self-calibration by automatically capturing images of the projection surface, detecting projector positions and overlap regions, and computing intensity scaling maps without requiring manual intervention. The calibration process is autonomous, eliminating the need for operators to physically adjust projector placements or manually configure alignment parameters.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical adjustment of projector positions with an automated computational system that uses image processing and algorithms to determine optimal intensity scaling. Instead of physically moving projectors to achieve alignment, the system processes digital images and applies computational corrections to intensity values.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Area of stationary object

If multiple projectors are used to create large displays, then display area increases, but brightness uniformity deteriorates in overlap regions

Engineering Contradiction:

Improvedisplay areaVSAvoidbrightness uniformity

Core Design Contradiction:

Area of stationary objectVSIllumination intensity

Solution Approach 1:

The system applies different intensity scaling values to different spatial regions of the projection. Specifically, pixels in overlap regions receive reduced intensity scaling factors compared to pixels in non-overlap regions. This local differentiation ensures that brightness uniformity is maintained across the entire display area while accommodating the additive nature of light in overlapping projector beams.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent dynamically adjusts the intensity parameter of projector pixels based on their spatial location and overlap status. By computing distance metrics from non-overlap regions and applying corresponding intensity scaling factors, the system transforms the uniform intensity output of projectors into a spatially varying intensity distribution that compensates for overlap effects.

Inventive Principle:

Principle #35Parameter changes

3Loss of time

If automated calibration is implemented, then calibration time is reduced, but measurement precision requirements increase

Engineering Contradiction:

Improvecalibration timeVSAvoidprojector position detection precision

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

The system introduces an intermediary image capture device (camera) that photographs the projection surface to indirectly measure projector positions and overlap regions. This intermediary approach allows the system to obtain precise spatial information without requiring direct sensor measurements from each projector, thereby reducing measurement precision requirements while maintaining calibration speed.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent transitions from direct spatial measurement in physical space to image space representation. By capturing the projection surface as a 2D image and analyzing pixel intensities and patterns in this dimensional transformation, the system can accurately determine projector positions and overlap regions using computationally efficient image processing techniques rather than precise physical measurements.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS8102332B2Intensity scaling for multi-projector displays

Publication Date: 2012.01.24 SEIKO EPSON CORP

AI summary

Methods having corresponding apparatus and computer-readable media comprise: receiving a first digital image representing a first composite projection, wherein each first composite projection comprises a plurality of overlapping component projections, wherein each of the component projections is generated by a respective projector; and generating one or more respective first intensity scaling maps for each of the projectors, comprising, for each of the first intensity scaling maps, identifying a displayed non-overlap projection region for the projector associated with the first intensity scaling map based on the first digital image, and generating a first intensity scaling map for the projector, comprising determining a distance to the nearest pixel within the displayed non-overlap region of the projector for each pixel outside the non-overlap region of the projector, and assigning a first intensity scaling value to each pixel outside the displayed non-overlap region of the projector based on the respective distance.