Projector Area Correction via Image Capture and RANSAC

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Solution Overview

Problem

Manual correction of projector projection areas in theaters is inaccurate and costly due to frequent misplacement caused by vibrations, leading to suboptimal projection of content on screens and walls.

Innovation Solution

An automated method and system using a photographing device to capture images of the projection surface with a structured light pattern, applying RANSAC technique for matching pixel coordinates, and utilizing a laser level to extract and correct the effective projection area, ensuring accurate alignment and obstruction removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual correction of projection area is performed by an engineer, then the work can be done with simple equipment, but the accuracy of correction is lowered and manpower cost increases

Engineering Contradiction:
Improveprojection area correction accuracyVSAvoidcorrection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces manual mechanical adjustment operations with an automated optical measurement system. A photographing device captures images of the projection surface, and a processor automatically calculates correction values through image processing and coordinate mapping, eliminating the need for manual visual inspection and physical adjustment by engineers.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a digital copy of the projection surface by photographing it with a photographing device. This captured image serves as a digital replica that can be processed, analyzed, and measured without physically touching or disturbing the actual projection surface, enabling precise automated correction.

Inventive Principle:
Principle #26Copying

2Reliability

If frequent projection area correction is performed manually, then projector misplacement issues are addressed, but the manpower and cost consumed increase

Engineering Contradiction:
Improveprojection service reliabilityVSAvoidcorrection operation efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system enables self-service correction by automatically detecting projector misplacement and calculating correction parameters without human intervention. The photographing device and processor work autonomously to identify the projection area, compute transformation matrices, and generate correction data, making the system self-correcting and eliminating repeated manual labor.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements a feedback mechanism where the photographing device continuously monitors the projection surface, detects deviations from the correct projection area, and feeds this information back to the correction system. This closed-loop approach automatically addresses misplacement issues as they occur, maintaining high reliability without requiring frequent manual interventions.

Inventive Principle:
Principle #23Feedback

3Productivity

If automated correction using photographing device is implemented, then correction accuracy and efficiency improve, but the device complexity and initial cost increase

Engineering Contradiction:
Improvecorrection operation speedVSAvoidautomated correction system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The photographing device serves multiple functions: it captures the projection surface for correction, verifies projection quality, and can potentially be used for other theater monitoring tasks. This multi-functionality justifies the added device complexity by providing broader utility beyond simple correction operations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces a processor as an intermediary between the photographing device and the projector control system. This intermediary component handles the complex image processing and coordinate transformation calculations, isolating the complexity from both the photographing device and the projector, and enabling automated correction through a dedicated computational layer.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Achieves high-quality automatic correction of projector areas with reduced manpower and costs, effectively removing obstructions and ensuring precise alignment across large-scale theaters with multiple surfaces.

Implementation Method 1

acquiring a first projection surface image photographed by a photographing device

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

mapping each pair of pixel coordinates of a projection area in the first projection surface image to each pair of pixel coordinates of a projection area projected by a projector

Methodology Applied
Scientific EffectLight projection: Light

Data Source

PatentEP3539288B1Method of automatically correcting projection area based on image photographed by photographing device and system therefor
Publication Date: 2022.08.03 CJ CGV
  • EP3539288B1 patent drawingFigure 1
  • EP3539288B1 patent drawingFigure 2
  • EP3539288B1 patent drawingFigure 3

AI summary

The present invention relates to automatic correction of an area on which contents are projected by a projector, i.e., a so- called projection area, in a theater, and specifically, to a method and system for automatically correcting a projection area by photographing a projection area in the theater using a photographing device such as a camera or the like, and matching the image photographed like this, coordinates of a projection area projected by the projector and finally a contents image projected on a projection surface such as a screen, a wall or the like so that eventually the contents image may be properly output in an effective projection area of a projection surface in the theater.