Multi-Projector Display Correction via Regional Segmentation

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Solution Overview

Problem

Existing multi-projection systems face challenges in adjusting display quality across an entire screen due to limited correction precision, as current methods focus on center projector adjustments and require extensive gamma correction processes involving test images for uniform RGB shades.

Innovation Solution

An output control apparatus that extracts display characteristics from test patterns projected onto the entire projection surface, calculates correction values using continuous sampling points, and applies these corrections to improve display quality efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If correction is performed only at center positions of projectors, then adjustment process is simplified, but correction precision is lowered

Engineering Contradiction:
Improveadjustment process simplicityVSAvoidcorrection precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The projection screen is divided into multiple measurement regions (center region and corner regions), and correction is performed independently for each region. This segmentation allows comprehensive coverage of the entire screen while maintaining systematic organization of the correction process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different correction values are calculated and applied for different regions of the projection screen. The correction characteristics are optimized locally for each region (center vs. corners) rather than applying a uniform correction across the entire screen, thereby improving overall correction precision.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If gamma correction is performed with uniform RGB shade test images, then color accuracy is improved, but adjustment time increases significantly

Engineering Contradiction:
Improvecolor accuracyVSAvoidadjustment time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

Brightness correction is performed first as a preliminary step before gamma correction. By pre-adjusting brightness to match across projectors, the subsequent gamma correction process becomes more efficient and requires less iterative adjustment, thereby reducing total adjustment time while maintaining color accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The method performs brightness correction to a sufficient degree (matching center region brightness) before proceeding to gamma correction. This partial completion of brightness adjustment reduces the workload for the subsequent gamma correction step, optimizing the overall adjustment process efficiency.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If correction values are calculated from entire projection surface data, then display quality across the screen is improved, but data processing complexity increases

Engineering Contradiction:
Improvedisplay qualityVSAvoiddata processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The projection surface is segmented into distinct measurement regions (center and corners), with sampling points distributed within each region. This segmentation simplifies data processing by organizing measurements into manageable regional datasets while still capturing comprehensive screen-wide characteristics.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The method uses continuous sampling points within measurement regions to obtain comprehensive display characteristics. By strategically selecting continuous sampling locations and adjusting measurement parameters (number of sampling points, region definitions), the system achieves high display quality assessment without excessive processing complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2999219B1Output control apparatus and output control system
Publication Date: 2019.03.06 RICOH CO LTD
  • EP2999219B1 patent drawingFigure 1
  • EP2999219B1 patent drawingFigure 2
  • EP2999219B1 patent drawingFigure 3

AI summary

An output control apparatus configured to control color information of projection image data to be output to one or more output devices, includes a display characteristic extraction unit configured to extract a display characteristic of the output device from test patterns having been output from the output device, and including at least one of gradation information, brightness information, and chromaticity information; a correction value calculation unit configured to calculate a correction value of the output device, based on the display characteristic obtained by the display characteristic extraction unit; and a correction unit configured to correct the projection image data to be output to the output device, based on the correction value calculated by the correction value calculation unit.