Light Field Imaging for Deflectometry

Light Field Imaging for Deflectometry

Author: Uhlig, David

Publisher: KIT Scientific Publishing

Published: 2023-07-14

Total Pages: 284

ISBN-13: 3731513064

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Optical measurement methods are becoming increasingly important for high-precision production of components and quality assurance. The increasing demand can be met by modern imaging systems with advanced optics, such as light field cameras. This work explores their use in the deflectometric measurement of specular surfaces. It presents improvements in phase unwrapping and calibration techniques, enabling high surface reconstruction accuracies using only a single monocular light field camera.


Book Synopsis Light Field Imaging for Deflectometry by : Uhlig, David

Download or read book Light Field Imaging for Deflectometry written by Uhlig, David and published by KIT Scientific Publishing. This book was released on 2023-07-14 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical measurement methods are becoming increasingly important for high-precision production of components and quality assurance. The increasing demand can be met by modern imaging systems with advanced optics, such as light field cameras. This work explores their use in the deflectometric measurement of specular surfaces. It presents improvements in phase unwrapping and calibration techniques, enabling high surface reconstruction accuracies using only a single monocular light field camera.


Tools for the Paraxial Optical Design of Light Field Imaging Systems

Tools for the Paraxial Optical Design of Light Field Imaging Systems

Author: Lois Mignard-Debise

Publisher:

Published: 2018

Total Pages: 0

ISBN-13:

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Light field imaging is often presented as a revolution of standard imaging. Indeed, it does bring more control to the user over the final image as the spatio-angular dimensions of the light field offer the possibility to change the viewpoint and refocus after the shot and compute the scene depth map.However, it complicates the work of the optical designer of the system for two reasons. The first is that there exist a multitude of different light field acquisition devices, each with its own specific design. The second is that there is no model that relates the camera design to its optical properties of acquisition and that would guide the designer in his task. This thesis addresses these observations by proposing a first-order optical model to represent any light field acquisition device. This model abstracts a light field camera as en equivalent array of virtual cameras that exists in object space and that performs the same sampling of the scene. The model is used to study and compare several light field cameras as well as a light field microscope setup which reveals guidelines for the conception of light field optical systems. The simulations of the model are also validated through experimentation with a light field camera and a light field microscope that was constructed in our laboratory.


Book Synopsis Tools for the Paraxial Optical Design of Light Field Imaging Systems by : Lois Mignard-Debise

Download or read book Tools for the Paraxial Optical Design of Light Field Imaging Systems written by Lois Mignard-Debise and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light field imaging is often presented as a revolution of standard imaging. Indeed, it does bring more control to the user over the final image as the spatio-angular dimensions of the light field offer the possibility to change the viewpoint and refocus after the shot and compute the scene depth map.However, it complicates the work of the optical designer of the system for two reasons. The first is that there exist a multitude of different light field acquisition devices, each with its own specific design. The second is that there is no model that relates the camera design to its optical properties of acquisition and that would guide the designer in his task. This thesis addresses these observations by proposing a first-order optical model to represent any light field acquisition device. This model abstracts a light field camera as en equivalent array of virtual cameras that exists in object space and that performs the same sampling of the scene. The model is used to study and compare several light field cameras as well as a light field microscope setup which reveals guidelines for the conception of light field optical systems. The simulations of the model are also validated through experimentation with a light field camera and a light field microscope that was constructed in our laboratory.


Reconstruction from Spatio-Spectrally Coded Multispectral Light Fields

Reconstruction from Spatio-Spectrally Coded Multispectral Light Fields

Author: Schambach, Maximilian

Publisher: KIT Scientific Publishing

Published: 2022-10-17

Total Pages: 238

ISBN-13: 3731512106

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In dieser Arbeit werden spektral kodierte multispektrale Lichtfelder untersucht, wie sie von einer Lichtfeldkamera mit einem spektral kodierten Mikrolinsenarray aufgenommen werden. Für die Rekonstruktion der kodierten Lichtfelder werden zwei Methoden entwickelt, eine basierend auf den Prinzipien des Compressed Sensing sowie eine Deep Learning Methode. Anhand neuartiger synthetischer und realer Datensätze werden die vorgeschlagenen Rekonstruktionsansätze im Detail evaluiert. -In this work, spatio-spectrally coded multispectral light fields, as taken by a light field camera with a spectrally coded microlens array, are investigated. For the reconstruction of the coded light fields, two methods, one based on the principles of compressed sensing and one deep learning approach, are developed. Using novel synthetic as well as a real-world datasets, the proposed reconstruction approaches are evaluated in detail.


Book Synopsis Reconstruction from Spatio-Spectrally Coded Multispectral Light Fields by : Schambach, Maximilian

Download or read book Reconstruction from Spatio-Spectrally Coded Multispectral Light Fields written by Schambach, Maximilian and published by KIT Scientific Publishing. This book was released on 2022-10-17 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: In dieser Arbeit werden spektral kodierte multispektrale Lichtfelder untersucht, wie sie von einer Lichtfeldkamera mit einem spektral kodierten Mikrolinsenarray aufgenommen werden. Für die Rekonstruktion der kodierten Lichtfelder werden zwei Methoden entwickelt, eine basierend auf den Prinzipien des Compressed Sensing sowie eine Deep Learning Methode. Anhand neuartiger synthetischer und realer Datensätze werden die vorgeschlagenen Rekonstruktionsansätze im Detail evaluiert. -In this work, spatio-spectrally coded multispectral light fields, as taken by a light field camera with a spectrally coded microlens array, are investigated. For the reconstruction of the coded light fields, two methods, one based on the principles of compressed sensing and one deep learning approach, are developed. Using novel synthetic as well as a real-world datasets, the proposed reconstruction approaches are evaluated in detail.


Machine Learning for Camera-Based Monitoring of Laser Welding Processes

Machine Learning for Camera-Based Monitoring of Laser Welding Processes

Author: Hartung, Julia

Publisher: KIT Scientific Publishing

Published: 2024-03-08

Total Pages: 258

ISBN-13: 3731513331

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The increasing use of automated laser welding processes causes high demands on process monitoring. This work demonstrates methods that use a camera mounted on the focussing optics to perform pre-, in-, and post-process monitoring of welding processes. The implementation uses machine learning methods. All algorithms consider the integration into industrial processes. These challenges include a small database, limited industrial manufacturing inference hardware, and user acceptance.


Book Synopsis Machine Learning for Camera-Based Monitoring of Laser Welding Processes by : Hartung, Julia

Download or read book Machine Learning for Camera-Based Monitoring of Laser Welding Processes written by Hartung, Julia and published by KIT Scientific Publishing. This book was released on 2024-03-08 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing use of automated laser welding processes causes high demands on process monitoring. This work demonstrates methods that use a camera mounted on the focussing optics to perform pre-, in-, and post-process monitoring of welding processes. The implementation uses machine learning methods. All algorithms consider the integration into industrial processes. These challenges include a small database, limited industrial manufacturing inference hardware, and user acceptance.


Computational, label, and data efficiency in deep learning for sparse 3D data

Computational, label, and data efficiency in deep learning for sparse 3D data

Author: Li, Lanxiao

Publisher: KIT Scientific Publishing

Published: 2024-05-13

Total Pages: 256

ISBN-13: 3731513463

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Deep learning is widely applied to sparse 3D data to perform challenging tasks, e.g., 3D object detection and semantic segmentation. However, the high performance of deep learning comes with high costs, including computational costs and the effort to capture and label data. This work investigates and improves the efficiency of deep learning for sparse 3D data to overcome the obstacles to the further development of this technology.


Book Synopsis Computational, label, and data efficiency in deep learning for sparse 3D data by : Li, Lanxiao

Download or read book Computational, label, and data efficiency in deep learning for sparse 3D data written by Li, Lanxiao and published by KIT Scientific Publishing. This book was released on 2024-05-13 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deep learning is widely applied to sparse 3D data to perform challenging tasks, e.g., 3D object detection and semantic segmentation. However, the high performance of deep learning comes with high costs, including computational costs and the effort to capture and label data. This work investigates and improves the efficiency of deep learning for sparse 3D data to overcome the obstacles to the further development of this technology.


Advancements in Optical Methods & Digital Image Correlation in Experimental Mechanics, Volume 3

Advancements in Optical Methods & Digital Image Correlation in Experimental Mechanics, Volume 3

Author: Ming-Tzer Lin

Publisher: Springer Nature

Published: 2019-12-04

Total Pages: 130

ISBN-13: 3030300099

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Advancement of Optical Methods & Digital Image Correlation in Experimental Mechanics, Volume 3 of the Proceedings of the 2019 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, the third volume of six from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on a wide range of optical methods ranging from traditional photoelasticity and interferometry to more recent DIC and DVC techniques, and includes papers in the following general technical research areas: DIC Methods & Its Applications Photoelsticity and Interferometry ApplicationsMicro-Optics and Microscopic SystemsMultiscale and New Developments in Optical MethodsDIC and its Applications for Inverse Problems


Book Synopsis Advancements in Optical Methods & Digital Image Correlation in Experimental Mechanics, Volume 3 by : Ming-Tzer Lin

Download or read book Advancements in Optical Methods & Digital Image Correlation in Experimental Mechanics, Volume 3 written by Ming-Tzer Lin and published by Springer Nature. This book was released on 2019-12-04 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advancement of Optical Methods & Digital Image Correlation in Experimental Mechanics, Volume 3 of the Proceedings of the 2019 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, the third volume of six from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on a wide range of optical methods ranging from traditional photoelasticity and interferometry to more recent DIC and DVC techniques, and includes papers in the following general technical research areas: DIC Methods & Its Applications Photoelsticity and Interferometry ApplicationsMicro-Optics and Microscopic SystemsMultiscale and New Developments in Optical MethodsDIC and its Applications for Inverse Problems


Light Field Methods for the Visual Inspection of Transparent Objects

Light Field Methods for the Visual Inspection of Transparent Objects

Author: Meyer, Johannes

Publisher: KIT Scientific Publishing

Published: 2019-08-22

Total Pages: 268

ISBN-13: 3731509121

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Book Synopsis Light Field Methods for the Visual Inspection of Transparent Objects by : Meyer, Johannes

Download or read book Light Field Methods for the Visual Inspection of Transparent Objects written by Meyer, Johannes and published by KIT Scientific Publishing. This book was released on 2019-08-22 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:


Light Field Imaging Applied to Reacting and Microscopic Flows

Light Field Imaging Applied to Reacting and Microscopic Flows

Author:

Publisher:

Published: 2014

Total Pages: 51

ISBN-13:

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Light field imaging, specifically synthetic aperture (SA) refocusing is a method used to combine images from an array of cameras to generate a single image with a narrow depth of field that can be positioned arbitrarily throughout the volume under investigation. Creating a stack of narrow depth of field images at varying locations generates a focal stack that can be sued to find the location of objects in three dimensions. SA refocusing is particularly useful with reconstructing it can also be used for shape reconstruction. This study applies SA refocusing to reacting flows and microscopic flows by performing shape reconstruction and 3D PIV on a flame, and 3D PIV on flow through a micro channel. The reacting flows in particular posed problems with the method. Reconstruction of flame envelope was successful except for significant elongation in the optical axis caused by cameras viewing the flame from primarily one direction. 3D PIV on reacting flows suffered heavily from the index of refraction generated by the flame. The refocusing algorithm used assumed the particles were viewed through a constant refractive index (RI) and does not compensate for variations in the RI. This variation caused apparent motion in the particles that obscured their true locations making the 3D PIV prone to error. A microlens array was placed in the imaging section of the setup to capture a light field from the scene, which was then refocusing using SA refocusing. PIV on these volumes was compared to a CFD simulation on the same channel. Comparisons showed that error was most significant near the boundaries and the step of the channel. The axial velocity in particular had significant error near the step were the axial velocity was highest. Flow-wise velocity, though, appeared accurate with average flow-wise error approximately 20% throughout the channel volume.


Book Synopsis Light Field Imaging Applied to Reacting and Microscopic Flows by :

Download or read book Light Field Imaging Applied to Reacting and Microscopic Flows written by and published by . This book was released on 2014 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light field imaging, specifically synthetic aperture (SA) refocusing is a method used to combine images from an array of cameras to generate a single image with a narrow depth of field that can be positioned arbitrarily throughout the volume under investigation. Creating a stack of narrow depth of field images at varying locations generates a focal stack that can be sued to find the location of objects in three dimensions. SA refocusing is particularly useful with reconstructing it can also be used for shape reconstruction. This study applies SA refocusing to reacting flows and microscopic flows by performing shape reconstruction and 3D PIV on a flame, and 3D PIV on flow through a micro channel. The reacting flows in particular posed problems with the method. Reconstruction of flame envelope was successful except for significant elongation in the optical axis caused by cameras viewing the flame from primarily one direction. 3D PIV on reacting flows suffered heavily from the index of refraction generated by the flame. The refocusing algorithm used assumed the particles were viewed through a constant refractive index (RI) and does not compensate for variations in the RI. This variation caused apparent motion in the particles that obscured their true locations making the 3D PIV prone to error. A microlens array was placed in the imaging section of the setup to capture a light field from the scene, which was then refocusing using SA refocusing. PIV on these volumes was compared to a CFD simulation on the same channel. Comparisons showed that error was most significant near the boundaries and the step of the channel. The axial velocity in particular had significant error near the step were the axial velocity was highest. Flow-wise velocity, though, appeared accurate with average flow-wise error approximately 20% throughout the channel volume.


Integrated Imaging and Vision Techniques for Industrial Inspection

Integrated Imaging and Vision Techniques for Industrial Inspection

Author: Zheng Liu

Publisher: Springer

Published: 2015-09-24

Total Pages: 541

ISBN-13: 1447167414

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This pioneering text/reference presents a detailed focus on the use of machine vision techniques in industrial inspection applications. An internationally renowned selection of experts provide insights on a range of inspection tasks, drawn from their cutting-edge work in academia and industry, covering practical issues of vision system integration for real-world applications. Topics and features: presents a comprehensive review of state-of-the-art hardware and software tools for machine vision, and the evolution of algorithms for industrial inspection; includes in-depth descriptions of advanced inspection methodologies and machine vision technologies for specific needs; discusses the latest developments and future trends in imaging and vision techniques for industrial inspection tasks; provides a focus on imaging and vision system integration, implementation, and optimization; describes the pitfalls and barriers to developing successful inspection systems for smooth and efficient manufacturing process.


Book Synopsis Integrated Imaging and Vision Techniques for Industrial Inspection by : Zheng Liu

Download or read book Integrated Imaging and Vision Techniques for Industrial Inspection written by Zheng Liu and published by Springer. This book was released on 2015-09-24 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: This pioneering text/reference presents a detailed focus on the use of machine vision techniques in industrial inspection applications. An internationally renowned selection of experts provide insights on a range of inspection tasks, drawn from their cutting-edge work in academia and industry, covering practical issues of vision system integration for real-world applications. Topics and features: presents a comprehensive review of state-of-the-art hardware and software tools for machine vision, and the evolution of algorithms for industrial inspection; includes in-depth descriptions of advanced inspection methodologies and machine vision technologies for specific needs; discusses the latest developments and future trends in imaging and vision techniques for industrial inspection tasks; provides a focus on imaging and vision system integration, implementation, and optimization; describes the pitfalls and barriers to developing successful inspection systems for smooth and efficient manufacturing process.


Machine Vision

Machine Vision

Author: Jürgen Beyerer

Publisher: Springer

Published: 2015-10-01

Total Pages: 802

ISBN-13: 3662477947

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The book offers a thorough introduction to machine vision. It is organized in two parts. The first part covers the image acquisition, which is the crucial component of most automated visual inspection systems. All important methods are described in great detail and are presented with a reasoned structure. The second part deals with the modeling and processing of image signals and pays particular regard to methods, which are relevant for automated visual inspection.


Book Synopsis Machine Vision by : Jürgen Beyerer

Download or read book Machine Vision written by Jürgen Beyerer and published by Springer. This book was released on 2015-10-01 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book offers a thorough introduction to machine vision. It is organized in two parts. The first part covers the image acquisition, which is the crucial component of most automated visual inspection systems. All important methods are described in great detail and are presented with a reasoned structure. The second part deals with the modeling and processing of image signals and pays particular regard to methods, which are relevant for automated visual inspection.