Camera-Specific Optical Center Measurement for Lens Distortion Correction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing camera calibration techniques, such as checkerboard calibration, are tedious and may result in inaccurate distortion correction due to variations in optical alignment between the lens and image sensor, especially in large volumes of cameras, leading to manufacturing inefficiencies and increased costs.

Innovation Solution

A camera-specific optical center measurement approach is used to correct distortion by measuring the actual optical center of each camera relative to its image sensor, allowing for high-accuracy distortion correction without structured calibration techniques, and storing this data for individual cameras to ensure consistent and efficient manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional checkerboard calibration techniques are used, then distortion correction can be achieved, but the process is tedious and time-consuming

Engineering Contradiction:
Improvedistortion correction accuracyVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts the essential calibration information by measuring only the optical center position using a laser alignment tool, eliminating the need for complex structured calibration patterns like checkerboards. This extraction of the critical parameter (optical center) alone enables sufficient distortion correction without the time-consuming full calibration process.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs self-calibration by automatically measuring the optical center and computing distortion correction parameters without requiring manual intervention or complex calibration procedures. The camera system can determine its own distortion characteristics through automated optical center measurement and coordinate transformation.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If traditional calibration techniques are used, then distortion correction can be achieved, but manufacturing costs increase

Engineering Contradiction:
Improvedistortion correction accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent extracts only the essential calibration parameter (optical center position) using simple laser alignment tools, eliminating the need for expensive complex calibration equipment and procedures. This selective extraction of critical information reduces manufacturing costs while maintaining sufficient distortion correction accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system uses inexpensive laser alignment tools and simple coordinate measurement methods instead of expensive specialized calibration equipment. The approach replaces costly traditional calibration systems with affordable alternatives that achieve the same functional result.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Productivity

If traditional calibration techniques are used, then distortion correction can be achieved, but accuracy decreases due to optical alignment variations

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoiddistortion correction accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies local quality by measuring and correcting distortion specifically at the optical center location rather than attempting uniform calibration across the entire field of view. By focusing calibration efforts on the critical optical center region and using coordinate transformations tailored to each camera's specific alignment, the system achieves high accuracy despite manufacturing variations.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system changes the calibration parameter from complex multi-parameter traditional calibration to a simplified optical center position measurement. By transforming the problem to measure only the optical center coordinates and using these to derive distortion correction parameters through mathematical transformation, the system achieves both high accuracy and manufacturing efficiency.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3994875B1Camera-specific distortion correction
Publication Date: 2025.08.27 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3994875B1 patent drawingFigure 1
  • EP3994875B1 patent drawingFigure 2
  • EP3994875B1 patent drawingFigure 3

AI summary

A camera includes an image sensor, a lens, memory, and a controller. The lens is positioned to direct object light from a scene onto the image sensor. The memory is configured to store a camera-specific optical center of the lens relative to the image sensor. The camera-specific optical center is measured after a position of the lens is center fixed relative to a position of the image sensor. The controller is configured to acquire a raw image of the scene via the image sensor and generate a distortion corrected image from the raw image based on at least the camera-specific optical center.