Lens Distortion Correction With Pseudo Calibration Images

Solution Overview

Problem

Existing methods for aligning a camera and a calibration chart for lens distortion correction in image compositing are inaccurate due to the lack of distortion information acquisition and manual position alignment, leading to deviations in peripheral views, especially with lenses having significant aberrations.

Innovation Solution

An information processing apparatus and method that includes acquiring a captured image of a calibration chart, a reference image, and lens distortion information, generating a pseudo image reflecting the distortion, and compositing it with the captured image to facilitate precise alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a grid-like calibration chart is captured and lens distortion amount is calculated using a dedicated application, then lens distortion correction becomes possible, but accurate position alignment between the chart and camera is difficult to achieve due to manual visual alignment

Engineering Contradiction:

Improvelens distortion measurement accuracyVSAvoidposition alignment accuracy

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent creates a pseudo image that copies the distortion characteristics of the lens by applying the measured distortion amount to a reference image of the calibration chart. This pseudo image serves as a visual guide that already incorporates the lens distortion, allowing the user to align the camera with the chart more accurately by comparing the captured image with the distorted reference image.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent introduces a composite image as an intermediary that combines the captured image and the pseudo image. This composite image displays both the actual captured image and the reference image with distortion applied, serving as a mediator that guides the user to achieve accurate alignment between the camera and calibration chart by visual comparison.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If position alignment is performed visually by the user, then the alignment process is simple to operate, but accurate alignment is not achieved leading to deviations in peripheral views

Engineering Contradiction:

Improvealignment operation simplicityVSAvoidposition alignment accuracy

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent creates a pseudo image that copies the distortion characteristics of the lens by applying the measured distortion amount to a reference image of the calibration chart. This pseudo image serves as a visual guide that already incorporates the lens distortion, allowing the user to align the camera with the chart more accurately by comparing the captured image with the distorted reference image.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent introduces a composite image as an intermediary that combines the captured image and the pseudo image. This composite image displays both the actual captured image and the reference image with distortion applied, serving as a mediator that guides the user to achieve accurate alignment between the camera and calibration chart by visual comparison.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If distortion information is acquired from camera metadata, then distortion correction is streamlined, but this method is not available for all image capturing lenses

Engineering Contradiction:

Improvedistortion correction efficiencyVSAvoidlens compatibility

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent performs preliminary measurement of the lens distortion amount by capturing an image of the calibration chart and calculating the distortion using a dedicated application. This measured distortion information is then stored and reused for generating pseudo images in future operations, eliminating the need to repeat the measurement process and enabling the system to work with lenses that do not provide distortion information in metadata.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12412305B2Information processing apparatus, information processing method, image capturing apparatus, storage medium for correcting lens distortion aberrations

Publication Date: 2025.09.09 CANON KK

AI summary

An information processing apparatus comprises a first acquisition unit that acquires a captured image obtained by capturing an image of a chart for calibration, a second acquisition unit that acquires a reference image which is an image of the chart that serves as a reference, a third acquisition unit that acquires information on distortion aberration of a lens used to capture the captured image, a first generation unit that generates a pseudo image which is an image obtained by reflecting the distortion aberration in the reference image, based on the reference image and the information on distortion aberration, and a second generation unit that generates a composite image obtained by compositing the captured image and the pseudo image.