This book provides a comprehensive guide to 3D Light-Field camera based imaging, exploring the working principles, developments and its applications in fluid mechanics and aerodynamics measurements. It begins by discussing the fundamentals of Light-Field imaging and theoretical resolution analysis, before touching upon the detailed optics design and micro-lens array assembly. Subsequently, Light-Field calibration methods that compensate for optical distortions and establish the relations between the image and real-word 3D coordinates are covered. This is followed by Light-Field 3D reconstruction algorithms which are elaborated for micrometer-scale particles and centimeter-scale physical models. Last but not least, implementations of the preceding procedures to selected fundamental and applied flow measurement scenarios are provided at the end of the book.
Development and Application of Light-Field Cameras in Fluid Measurements gives an in-depth analysis of each topic discussed, making it ideal as both an introductory and reference guide for researchers and postgraduates interested in 3D flow measurements.
Author(s): Shengxian Shi, T. H. New
Publisher: Springer
Year: 2022
Language: English
Pages: 226
City: Singapore
Preface
Contents
Contributors
Abbreviations
Symbols
1 Introduction
The Light-field
Capturing Light-field
Would Light-field Imaging be Beneficial for PIV?
References
2 Light-field Camera Working Principles
Introduction
Principles of Conventional Imaging
Imaging Principles of Unfocused Light-field Camera
Imaging Principles of Focused Light-field Camera
Synthetic Image Generation and Point Source Response
Light-field Camera Design
Microlens Array
Embedded-MLA Light-field Camera
Relayed-MLA Light-field Camera
Microlens Calibration
Summary
References
3 Volumetric Calibration for Light-field Camera with Regular and Scheimpflug Lens
Calibration for Light-field Camera with Regular Lens
Determination of Plenoptic Disc Feature Diameter and Centre
Calculation of the Weighting Coefficient
Simulation Studies
Calibration Experiment
Calibration for Light-field Camera with Scheimpflug Lens
Plenoptic Disk Feature Extraction
Calibration for Optical Distortions
Calibration Experiment
References
4 Light-field Particle Image Velocimetry
Introduction
Dense Ray Tracing-based MART 3D Reconstruction of Light-field Particle Images
Reconstructed 3D Particle Elongations
Reconstruction Quality and Speed
Reconstruction Accuracy Under Unsteady Flow Conditions
Experimental Validations
Comparison with Tomo-PIV
Synthetic Particle Image Generation and Analysis
Dual-Camera LF-PIV
Initial Validation of Dual Camera Principles
Effects of Particle Density and Separation Angle
Validations with Simulation and Experiment
References
5 Simultaneous 3D Surface Geometry and Pressure Distribution Measurement
Introduction
Pressure Estimation from Central Perspective Images
3D Model Geometry Reconstruction from Single Light-field Image
Application of Light-field PSP to Mach 5 Wind Tunnel Experiment
References
6 Light-field PIV Implementation and Case Studies
Introduction
Adverse Pressure-Gradient Turbulent Boundary Layers
Impinging Jets
Linear Cascades
Supersonic Jets
References
7 Future Developments of Light-field-Based Measurements
Light-field Multi-spectral Radiation Thermometry
3D Geometry Measurements
Droplet and Splash Measurements
3D Flame Structure Reconstructions
3D Background Oriented Schlieren
Summary
References
List of Formulas
