Lateral Chromatic Aberration Correction via Design-Error Component Separation

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Solution Overview

Problem

Existing image processing technologies fail to accurately correct lateral chromatic aberration caused by manufacturing errors in image capturing optical systems, leading to degraded image quality and increased data storage requirements.

Innovation Solution

An image processing apparatus that separates and corrects lateral chromatic aberration into components based on design values and manufacturing errors, using a combination of rotationally symmetric and asymmetric components, allowing for high-accuracy correction with reduced data storage by interpolating shift components from fewer measurement conditions and representing rotationally symmetric components with lower-order polynomials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the lateral chromatic aberration is corrected by image processing based on previously stored data, then the color shift in the object image is reduced, but the correction accuracy deteriorates when manufacturing errors cause changes in the lateral chromatic aberration

Engineering Contradiction:
Improvecorrection accuracyVSAvoidlateral chromatic aberration consistency
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent segments the lateral chromatic aberration correction data into multiple components: a first component representing the design value and a second component representing the manufacturing error. This segmentation allows the system to store and process correction data in a structured manner, improving correction accuracy by addressing different sources of aberration separately while maintaining efficient data storage.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the real aberration amount is measured for each lens parameter at the time of manufacture to reflect manufacturing errors, then the correction accuracy improves, but the mass productivity decreases and manufacturing cost increases

Engineering Contradiction:
Improvecorrection accuracyVSAvoidmass productivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent extracts only the essential manufacturing error component from the complete lateral chromatic aberration data. By separating and storing only the second component that represents manufacturing errors, the system achieves accurate correction without requiring comprehensive measurement of all lens parameters, thereby maintaining mass productivity while improving correction accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the parameter representation by decomposing the lateral chromatic aberration into distinct components (design value component and manufacturing error component). This parameter transformation allows the system to work with simplified data structures that require less measurement information while maintaining high correction accuracy.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the correction amount is stored for each pixel to adequately correct the lateral chromatic aberration, then the correction accuracy improves, but the correction data amount increases

Engineering Contradiction:
Improvecorrection accuracyVSAvoidcorrection data amount
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by differentiating the correction approach for different regions and components. The first component (design value) and second component (manufacturing error) are handled with different data structures and storage requirements. This allows efficient data storage by applying appropriate correction strategies to different parts of the aberration problem without requiring full pixel-level data for all components.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3236651B1Image processing apparatus, image capturing apparatus, lens apparatus, image processing method, and program
Publication Date: 2020.06.10 CANON KK
  • EP3236651B1 patent drawingFigure 1A~1E
  • EP3236651B1 patent drawingFigure 2
  • EP3236651B1 patent drawingFigure 3

AI summary

An image processing apparatus (104) includes an acquirer (104b) configured to acquire information related to a lateral chromatic aberration, and a corrector (104c) configured to correct an image to reduce the lateral chromatic aberration based on the information related to the lateral chromatic aberration, the information related to the lateral chromatic aberration includes a first component related to a design value, and a second component related to a manufacturing error, each of the first component and the second component is a rotationally symmetric component.