Virtual Correspondence Points for 3D Light-Triangulation Calibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional calibration methods for 3D imaging systems based on light triangulation rely on accurately manufactured calibration targets with physical reference features, which are prone to manufacturing limitations, lens distortions, and unwanted reconstruction artifacts, leading to unstable depth measurements and triangulation artifacts.
Innovation Solution
Utilize virtual intersections between real world lines and image sensor lines derived from multiple images of a calibration object's surfaces, eliminating the need for physical reference features and simplifying the calibration process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If physical reference features are used on calibration targets, then calibration points can be identified, but manufacturing limitations and lens distortions cause unstable depth measurements and triangulation artifacts
Solution Approach 1:
The patent replaces physical reference features with virtual reference features that are computed from the intersection of light plane equations and surface equations. These virtual features are derived mathematically rather than physically manufactured, eliminating manufacturing limitations and lens distortion effects that plague physical calibration targets.
Solution Approach 2:
The patent substitutes the mechanical/physical calibration target with a computational approach using equations of light planes and surfaces. Instead of relying on physical features that suffer from manufacturing tolerances and optical distortions, the system uses mathematical intersections to define calibration points, replacing physical measurement with computational geometry.
2Measurement precision
If complex calibration targets with physical reference features are manufactured, then accurate calibration points can be obtained, but the manufacturing process becomes more difficult and time-consuming
Solution Approach 1:
The patent creates virtual copies of reference features through mathematical computation rather than physical fabrication. By computing intersections of light planes with known surface equations, the system generates calibration points without needing to manufacture complex physical targets, dramatically simplifying the calibration process.
Solution Approach 2:
The patent changes the fundamental parameter definition from physical feature coordinates to mathematical intersection points. This parameter transformation allows calibration to be performed using computational geometry rather than physical manufacturing, converting a fabrication problem into a calculation problem that can be solved with standard equations.
3Ease of operation
If physical reference features are used, then calibration can be performed, but lens distortions and perspective effects introduce measurement errors
Solution Approach 1:
The patent replaces the optical measurement path that is subject to lens distortions with a direct mathematical computation. By calculating calibration points as intersections of light plane equations with surface equations in 3D space, the system bypasses the image formation process entirely, eliminating perspective effects and lens distortion from the calibration measurement.
Solution Approach 2:
The patent introduces mathematical equations of light planes and surfaces as intermediaries between the physical light source and the calibration points. These equations serve as a mediator that directly relates the light geometry to spatial coordinates without requiring image capture and processing, thereby eliminating optical distortion effects.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces negative effects associated with physical reference features, allowing for more accurate and stable 3D imaging by using simpler, easier-to-manufacture calibration objects and improving the mapping between image sensor and real world coordinates.
Implementation Method 1
reflected light resulting from said light plane intersecting with and thereby causing reflections from a surface
Implementation Method 2
imaging by said camera of reflected light resulting from said light plane intersecting with and thereby causing reflections from a surface
Data Source
AI summary
Method and device(s) for provision of a pair of real world and image sensor correspondence points for use in calibration of an imaging system (405) for three dimensional imaging based on light triangulation. Said real world point (514-1; 529-1) being provided (801) as a first virtual intersection between a first real world line (512a; 527a) and a second real world line (512b; 527b). Said image sensor point (544-1; 554-1) being provided (802) as a second virtual intersection between a first image line (542a; 552a) and a second image line (542b; 552b). A first image (540a; 550a) by the imaging system comprises captured light that images the first real world line (512a; 527a) and a second image (540b; 550b) by the imaging system comprises captured light that images the second real world line (512b; 527b). The first image line (542a; 552a) corresponds to positions of intensity peaks of said captured light in the first image (540a; 550a) and the second image line (542b; 552b) corresponds to positions of intensity peaks of said captured light in the second image (540b; 550b).