Camera-Projector Calibration for Surface Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing projector systems face challenges in accurately aligning projected images with markings on non-traditional surfaces, such as sports fields or game boards, due to variations in surface geometry and markings.

Innovation Solution

A camera-projector calibration system that uses a computing device to generate pose data and determine the positions of markings on the surface, allowing for precise alignment of projected images by superimposing a template image onto a camera image and applying a correction model to ensure accurate alignment with surface features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional projector systems are used on non-traditional surfaces, then the system complexity remains low, but the alignment precision between projected images and surface markings deteriorates

Engineering Contradiction:
Improvealignment precisionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system captures an image of the marked surface using a camera, detects the positions and orientations of markings, compares them with template marking positions, and uses this feedback to calculate transformation parameters that align the projected image with the actual surface markings, thereby resolving the alignment precision issue

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual mechanical alignment methods with an automated computer vision system that uses image processing, feature detection, and computational geometry to automatically determine alignment parameters, improving precision while managing system complexity through software-based solutions

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

2Adaptability or versatility

If the system accommodates variations in surface geometry, then the adaptability improves, but the calibration process complexity increases

Engineering Contradiction:
Improvesurface geometry adaptabilityVSAvoidcalibration process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system handles diverse surface geometries by computing transformation parameters (rotation, translation, scaling, perspective correction) that adapt the projected image to match the detected marking configurations, allowing the same hardware to work across different surfaces without physical modifications

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The calibration system is designed to handle multiple types of markings (circles, squares, triangles) and various surface geometries (flat, curved, angled) using a unified approach based on feature detection and transformation calculations, making the system universally applicable to different projection scenarios

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If iterative alignment algorithms are used, then the alignment accuracy improves, but the calibration time increases

Engineering Contradiction:
Improvealignment accuracyVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary detection of marking positions and orientations before calculating the final transformation parameters, allowing for a direct computation approach rather than iterative refinement, thus reducing calibration time while maintaining accuracy

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent skips the traditional iterative alignment process by using direct geometric calculations based on detected marking features, rapidly computing transformation parameters in a single step rather than through multiple iterative cycles, thereby reducing calibration time

Inventive Principle:
Principle #21Skipping (Rushing through)

Data Source

PatentEP3322182B1System and method for projecting images on a marked surface
Publication Date: 2024.08.14 CHRISTIE DIGITAL SYSTEMS USA INC
  • EP3322182B1 patent drawingFigure 1
  • EP3322182B1 patent drawingFigure 2
  • EP3322182B1 patent drawingFigure 3

AI summary

A system (200), method and computer readable medium for projecting images on a marked surface (215). The system includes a memory storage unit (222), a projector (207), a camera (214), an input device (225) for receiving input data to align correspondence points in a template image with features on the marked surface (215), a computing device (201) for calculating a correction model, and a rendering device for generating image data. The method involves projecting a template image to generate a camera image, receiving input data, calculating a correction model based on the input data and generating and projecting image data. The computer readable medium is encoded with codes to direct a processor to carry out the method.