Dual-Light Camera Calibration via Optical Reference Markers

Solution Overview

Problem

Dual-light cameras, which combine thermal and visible light imaging, face challenges in aligning images due to physical displacement and angle variations, leading to inaccurate fusion of images captured by separate sensors, making traditional mechanical alignment expensive and unreliable.

Innovation Solution

An imaging calibration method that acquires and processes thermal and visible light images using calibration frames to generate parameters for adjusting the position of thermal imaging images within visible light images, allowing for accurate alignment and fusion without relying on physical displacement or angle adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If mechanical alignment is used to align sensors or cameras, then alignment precision is improved, but manufacturing cost and complexity increase significantly

Engineering Contradiction:

Improvealignment precisionVSAvoidmanufacturing complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical alignment system with an optical calibration system. Instead of physically adjusting sensor positions mechanically, the invention uses optical fields (laser lines) and image processing to detect and compensate for alignment deviations. The calibration frame with laser-projected lines provides optical reference markers that are captured by sensors, and software algorithms calculate compensation parameters to achieve precise alignment without mechanical adjustments.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a calibration frame as an intermediary object between the sensors and the target scene. This calibration frame contains laser-projected line patterns that serve as reference markers. By capturing images of these intermediate markers, the system can indirectly measure and correct alignment deviations between sensors, avoiding direct mechanical alignment of the sensors themselves.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If mechanical alignment is used to align sensors or cameras, then alignment precision is improved, but reliability decreases due to potential displacement during use

Engineering Contradiction:

Improvealignment precisionVSAvoidalignment stability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent performs preliminary calibration before actual operation to establish compensation parameters. The calibration frame is positioned in advance, laser lines are projected, and images are captured to calculate the alignment deviation between sensors. These pre-calculated compensation parameters are stored and applied during normal operation, allowing the system to maintain accurate alignment without relying on permanent mechanical adjustments that may shift over time.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical alignment system with an optical calibration system. Instead of physically adjusting sensor positions mechanically, the invention uses optical fields (laser lines) and image processing to detect and compensate for alignment deviations. The calibration frame with laser-projected lines provides optical reference markers that are captured by sensors, and software algorithms calculate compensation parameters to achieve precise alignment without mechanical adjustments.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If separate sensors or cameras are used for thermal and visible light imaging, then functional versatility is improved, but image alignment becomes difficult due to physical displacement

Engineering Contradiction:

Improvedual-light imaging capabilityVSAvoidimage alignment accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent introduces a calibration frame as an intermediary object between the sensors and the target scene. This calibration frame contains laser-projected line patterns that serve as reference markers. By capturing images of these intermediate markers, the system can indirectly measure and correct alignment deviations between sensors, avoiding direct mechanical alignment of the sensors themselves.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical alignment system with an optical calibration system. Instead of physically adjusting sensor positions mechanically, the invention uses optical fields (laser lines) and image processing to detect and compensate for alignment deviations. The calibration frame with laser-projected lines provides optical reference markers that are captured by sensors, and software algorithms calculate compensation parameters to achieve precise alignment without mechanical adjustments.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS11995867B2Method and apparatus for imaging calibration, and dual-light camera

Publication Date: 2024.05.28 AUTEL ROBOTICS CO LTD

AI summary

Embodiments of the present invention discloses an imaging calibration method and apparatus for a dual-light camera and a dual-light camera. A thermal imaging image including a first calibration frame image and a visible light image including a second calibration frame image are acquired. The first calibration frame image and the second calibration frame image are images of a same calibration frame respectively photographed by a thermal imaging camera and a visible light camera. First position information of the first calibration frame image in the thermal imaging image and second position information of the second calibration frame in the visible light image are acquired. Calibration parameters are generated according to the first position information and the second position information. A position of the thermal imaging image synthesized in the visible light image in the visible light image is adjusted according to the calibration parameters.