Camera Calibration Assessment Using Statistical and Systematic Error Metrics

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Solution Overview

Problem

Camera calibration methods face challenges in accurately determining model parameters and assessing errors, particularly systematic errors and residual parameter uncertainties, which require expert knowledge and complex experiments, limiting their usability by laypersons and affecting the precision of subsequent processing steps.

Innovation Solution

A method and system for assessing camera calibration that provides two quality measures: a statistical error metric based on the uncertainty of model parameters and a systematic error measure, allowing for the quantification of both types of errors using a matrix that describes the mapping error and detector noise, enabling direct feedback for improving calibration processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If expert knowledge and complex control experiments are used to assess camera calibration, then measurement precision is improved, but device complexity and ease of operation deteriorate

Engineering Contradiction:
Improvecalibration accuracyVSAvoidcomplexity of calibration process
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The calibration assessment method enables the camera system to self-evaluate its calibration quality using automatically computed quality measures (RMSE and uncertainty metric) derived from calibration images and parameters, eliminating the need for expert intervention and complex control experiments while maintaining high measurement precision

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical control experiments and expert judgment with automated computational methods that calculate calibration quality metrics directly from image data and model parameters, substituting physical experimentation with mathematical processing

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

2Measurement precision

If expert knowledge and complex control experiments are used to assess camera calibration, then measurement precision is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvecalibration accuracyVSAvoidusability by laypersons
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system automatically computes calibration quality measures and provides direct feedback without requiring user expertise, enabling laypersons to perform and assess calibration by simply capturing calibration images and allowing the automated processing to evaluate results using RMSE and uncertainty metrics

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements automated feedback mechanisms that provide direct quality assessment results to users, enabling them to understand calibration quality without expert knowledge and make informed decisions about whether additional calibration images are needed

Inventive Principle:
Principle #23Feedback

3Productivity

If fewer measurements are taken during calibration, then productivity is improved, but measurement precision deteriorates due to high residual parameter uncertainties

Engineering Contradiction:
Improvecalibration speedVSAvoidparameter uncertainty
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The uncertainty metric provides immediate feedback on the quality of calibration data, enabling automated determination of whether additional calibration images are necessary, thus optimizing the trade-off between calibration speed and precision without requiring fixed numbers of measurements

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The method allows for adaptive calibration where the number of measurements is adjusted based on quality metrics - using fewer measurements when quality is sufficient and adding measurements only when the uncertainty metric indicates improvement is needed

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS11748910B2Method for assessing a camera calibration
Publication Date: 2023.09.05 ROBERT BOSCH GMBH
  • US11748910B2 patent drawing
  • US11748910B2 patent drawing
  • US11748910B2 patent drawing

AI summary

A method for assessing a camera calibration, in which a first quality measure is ascertained. A statistical error is assessed using the first quality measure. An expected value for a mapping error is ascertained. Optimal model parameters and their covariance matrix initially are accessed. A matrix of a mapping error is then determined. Finally, the expected value of the mapping error is ascertained.