Projector Keystone Correction via Marker Image Analysis

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Solution Overview

Problem

Current technologies face challenges in efficiently reducing keystone distortion in projection images when the projector's position changes relative to the projection surface, especially in retail settings, and in ensuring video content can be displayed at arbitrary positions without distortion, especially when projection light is obstructed by shop items.

Innovation Solution

An image generation method and system that uses a portable device to take images of the projection surface with a marker image projected, generates distortion correction parameters, displays the projection area, allows users to position video content, and corrects the image to reduce distortion, enabling video content to be placed at any position within the projection area with appropriate size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If keystone distortion correction is performed using marker images and positional relationships, then projection image distortion is reduced, but the workload increases significantly when projection screen position changes

Engineering Contradiction:

Improveprojection image distortion correctionVSAvoidworkload for distortion correction

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The system automatically detects the projection surface position and performs distortion correction without requiring manual marker placement or complex calculations by the user. The projector itself captures images of the projection surface and autonomously computes correction parameters, making the system self-configuring when the projection screen moves to new positions.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the traditional mechanical/optical marker-based distortion correction system with an image processing-based system. Instead of using physical markers and geometric calculations, the system uses digital image capture, processing, and automated parameter generation to achieve distortion correction, significantly reducing manual workload.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If projection light is blocked by goods, furniture, or fixtures, then expected decorative effect cannot be obtained, but restricting video content to unblocked areas reduces flexibility

Engineering Contradiction:

Improvedecorative effectVSAvoidvideo content placement flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system performs preliminary detection of the projection surface area and identifies unblocked regions before video content is displayed. By pre-mapping the usable projection area and storing this information, the system can automatically adapt video content placement to avoid blocked regions, maintaining both decorative effectiveness and placement flexibility.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts video content placement based on real-time detection of blocked areas. When goods, furniture, or fixtures obstruct the projection light, the system automatically modifies the display area and repositions video content within the remaining unblocked regions, ensuring the decorative effect is maintained while adapting to changing environmental conditions.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If video content is disposed at arbitrary positions in the projection area, then user flexibility is improved, but maintaining appropriate size and minimal distortion becomes more difficult

Engineering Contradiction:

Improvevideo content position selectionVSAvoidvideo content size and distortion control

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system uses feedback from captured images of the projection surface to automatically calculate optimal video content size and position. By continuously monitoring the actual projection area and distortion characteristics, the system adjusts video content parameters to maintain appropriate sizing and minimal distortion regardless of the user-selected position within the projection area.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system automatically changes video content parameters (position, size, aspect ratio) based on the detected projection surface characteristics and selected display area. When a user chooses an arbitrary position within the unblocked projection area, the system computes the appropriate parameter adjustments needed to maintain proper video content dimensions and minimize distortion at that specific location.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11503261B2Image generation method, image generation system, and non-transitory computer-readable storage medium storing program

Publication Date: 2022.11.15 SEIKO EPSON CORP

AI summary

A processing device generates a marker image to use as a reference for correcting a shape of a projection image projected on a projection surface from a projector, takes a taken image of the projection surface using the imaging device from an imaging position different from an observation position from which the projection surface is observed, generates a parameter for reducing a distortion of the projection image based on the marker image included in the taken image, displays an area image representing a range wherein projection can be performed on the projection surface on the display device, disposes a video content at an indicating position in the area image with an input to the input device, generates an original image including the video content, and corrects the original image thereby generating an input image for input to a projector configured to project the projection image.