Camera-Projector Recalibration Using Reduced Test Patterns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The process of projection mapping onto three-dimensional surfaces is complex due to the need for precise calibration of multiple projectors, which requires numerous calibration test patterns and can be time-consuming, especially when system perturbations occur, such as thermal effects or movement of the projector, camera, or surface.
Innovation Solution
A method and system that use a reduced set of test patterns to recalibrate camera-projector correspondences, including a first recalibration mode with a single test pattern and a second mode with two test patterns, allowing for efficient recalibration by projecting specific patterns onto the surface and using estimation functions to determine updated correspondences between camera and projector points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a full set of ten or more test patterns is used for calibration, then measurement precision and reliability of camera-projector correspondences are improved, but loss of time and productivity deteriorate
Solution Approach 1:
The patent applies partial action by using only a reduced subset of test patterns (e.g., 2-5 patterns instead of 10+) for recalibration operations. The system determines that full calibration is not always necessary - a partial recalibration with fewer patterns suffices for maintaining adequate precision while significantly reducing time loss during perturbations or drift corrections.
Solution Approach 2:
The patent implements dynamic calibration strategy where the system adapts between full calibration mode (using all test patterns) and reduced recalibration mode (using fewer patterns) based on operational needs. The controller dynamically selects the appropriate calibration depth, transitioning from comprehensive initial calibration to faster periodic recalibrations using subsets of patterns.
2Manufacturing precision
If numerous test patterns are projected for calibration, then manufacturing precision of projector alignment is improved, but productivity and ease of operation worsen
Solution Approach 1:
The system uses partial action by projecting only the necessary subset of test patterns required for maintaining projector alignment precision. Instead of always projecting all 10+ patterns, the controller selects minimal subsets (2-5 patterns) for recalibration, thereby maintaining manufacturing precision while avoiding excessive productivity loss.
Solution Approach 2:
The calibration process is segmented into distinct phases: initial full calibration using all test patterns to establish baseline precision, followed by periodic recalibration using segmented subsets of patterns. This segmentation allows the system to maintain precision requirements while improving overall productivity through faster incremental updates.
3Reliability
If a full calibration is performed frequently to correct system drift, then reliability of projection mapping is improved, but loss of time and productivity deteriorate
Solution Approach 1:
The patent applies partial action for reliability maintenance by using reduced test pattern subsets for frequent recalibration operations. The system achieves adequate reliability correction for thermal drift and movement perturbations using only 2-5 patterns instead of full sets, significantly reducing the time penalty of frequent reliability checks and corrections.
Solution Approach 2:
The system implements periodic recalibration using reduced test pattern sets at optimized intervals. Rather than continuous full calibration or ad-hoc recalibration, the controller performs periodic updates using minimal patterns, balancing reliability maintenance with time efficiency. This periodic partial recalibration prevents drift accumulation while minimizing interruption to projection mapping operations.
Data Source
AI summary
A device, system and method for generating updated camera-projector correspondences from a reduced set of test patterns is provided. When a predetermined correspondences between projector points and camera points in an initial relative position of a projector and a camera have been previously determined, a recalibration therebetween may occur by projecting a single test pattern derived from the predetermined correspondences to estimate movement therebetween. When the movement is too great to be estimated by a single test pattern, another test pattern may be projected to determine an estimation function for the movement and in particular, estimate movement of one or more camera points in the projected images due to relative movement of the projector and the camera from the initial relative position to a current relative position.