Camera Parameter Calibration Using Multi-Checkerboard Single-Shot Imaging

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Solution Overview

Problem

Existing camera calibration methods require multiple adjustments of the checkerboard target's position or posture and multiple image captures, leading to low efficiency and increased error.

Innovation Solution

A method that involves obtaining a calibration image with multiple checkerboards, determining checkerboard corners, generating checkerboards, converting them to a world coordinate system, and calculating camera parameters based on the projection relationship between these corners, allowing for single-shot calibration without repeated adjustments or captures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple adjustments of checkerboard target position or posture are performed to calibrate camera parameters, then the calibration can be completed, but the calibration efficiency is low and time consumption increases

Engineering Contradiction:
Improvecamera parameter calibration accuracyVSAvoidcalibration efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent merges multiple checkerboard targets into a single calibration image, capturing multiple checkerboards in different positions and postures simultaneously. This combines what would traditionally require multiple separate captures into one single shot, thereby improving calibration efficiency while maintaining accuracy

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extends the calibration approach from single checkerboard in single image to multiple checkerboards in one image. By utilizing the dimensional aspect of spatial arrangement within a single image frame, the method captures multiple calibration targets without requiring multiple adjustments or captures

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If multiple image captures are performed to obtain calibration data, then sufficient calibration information is obtained, but the calibration process becomes time-consuming

Engineering Contradiction:
Improvecalibration data sufficiencyVSAvoidcalibration time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Multiple checkerboard targets are merged into a single calibration image, allowing the system to obtain calibration data from multiple positions and postures simultaneously. This eliminates the need for multiple sequential captures, significantly reducing calibration time while ensuring sufficient calibration data is obtained

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If multiple adjustments and captures are performed, then comprehensive calibration data is collected, but error accumulation increases

Engineering Contradiction:
Improvecalibration data comprehensivenessVSAvoidcalibration error rate
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

By capturing multiple checkerboards in a single image, the patent eliminates repeated adjustments and captures that would introduce cumulative errors. The simultaneous capture ensures consistent imaging conditions across all checkerboards, reducing error accumulation while maintaining comprehensive calibration data

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3648055B1Camera parameter calibration method, device, apparatus, and system
Publication Date: 2022.08.03 HANGZHOU HIKVISION DIGITAL TECHNOLOGY CO LTD
  • EP3648055B1 patent drawingFigure 1~2
  • EP3648055B1 patent drawingFigure 3~4
  • EP3648055B1 patent drawingFigure 5

AI summary

Embodiments of the present application provide a method, apparatus, device and system for calibrating parameters of a camera. In this solution, a camera performs image capturing on multiple checkerboard targets to obtain a calibration image, in other words, the calibration image contains multiple checkerboards, and the camera parameters are solved based on the calibration image containing the multiple checkerboards. In a first aspect, the calibration image contains multiple checkerboards, so that it is not necessary to adjust the position or posture of a checkerboard target for multiple times and to capture a calibration image with respect to the checkerboard target for multiple times, thereby improving the calibration efficiency. In a second aspect, the fact of capturing a calibration image with respect to the checkerboard target for multiple times results in a relatively large error for capturing, while this error for capturing is reduced by applying this solution.