IMAGE DISTORTION CORRECTION FOR BIPRISM-BASED SINGLE-LENS STEREOVISION SYSTEM

Ph.DDOCTOR OF PHILOSOPH

Analysis and optimization of the stereo-system with a four-mirror adapter

Stereo imaging is becoming an important diagnostic tool in many practical applications throughout the industries. In the diagnostic procedure two views are used to provide in-depth information of the observing object. The conventional two-synchronized-camera systems, used in most applications, pose difficulty to people new to the applications, especially when off-the-shelf cameras have to be used. In this article, several commonly used single camera stereo systems are reviewed and studied. The stereo system with a four-mirror adapter in particular is analyzed, whereafter an improvement is made to achieve the maximum field of view (FOV) of the stereo system with the four-mirror adapter

Computational Cameras: Approaches, Benefits and Limits

A computational camera uses a combination of optics and software to produce images that cannot be taken with traditional cameras. In the last decade, computational imaging has emerged as a vibrant field of research. A wide variety of computational cameras have been demonstrated - some designed to achieve new imaging functionalities and others to reduce the complexity of traditional imaging. In this article, we describe how computational cameras have evolved and present a taxonomy for the technical approaches they use. We explore the benefits and limits of computational imaging, and describe how it is related to the adjacent and overlapping fields of digital imaging, computational photography and computational image sensors

Optimal calibration of a prism-based videoendoscopic system for precise 3D measurements

Modern videoendoscopes are capable of performing precise three-dimensional (3D) measurements of hard-to-reach elements. An attachable prism-based stereo adapter allows one to register images from two different viewpoints using a single sensor and apply stereoscopic methods. The key condition for achieving high measurement accuracy is the optimal choice of a mathematical model for calibration and 3D reconstruction procedures. In this paper, the conventional pinhole camera models with polynomial distortion approximation were analyzed and compared to the ray tracing model based on the vector form of Snell’s law. We, first, conducted a series of experiments using an industrial videoendoscope and utilized the criteria based on the measurement error of a segment length to evaluate the mathematical models considered. The experimental results confirmed a theoretical conclusion that the ray tracing model outperforms the pinhole models in a wide range of working distances. The results may be useful for the development of new stereoscopic measurement tools and algorithms for remote visual inspection in industrial and medical applications.The Russian Science Foundation (project #7-19-01355) financially supported the work. The authors thank A. Naumov, A. Shurygin and D. Khokhlov for continuous technical support

Single-lens multi-ocular stereovision using prism

Ph.DDOCTOR OF PHILOSOPH

Holography

This book depicts some differences from the typical scientific and technological literature on the theoretical study of holography and its applications. It offers topics that are not very commercial nor known, which will allow a different view of the field of optics. This is evident in chapters such as "Electron Holography of Magnetic Materials", "Polarization Holographic Gratings in Polymer Dispersed Formed Liquid Crystals", and "Digital Holography: Computer-generated Holograms and Diffractive Optics in Scalar Diffraction Domain". The readers will gain a different view of the application areas of holography and the wide range of possible directions that can guide research in the fields of optics

Depth recovery and parameter analysis using single-lens prism based stereovision system

Ph.DDOCTOR OF PHILOSOPH

An integrated python-based open-source Digital Image Correlation Software for in-plane and out-of-plane measurements (Part 2)

Funding Information: The authors would like to acknowledge Fundação para a Ciência e a Tecnologia (FCT-MCTES) throughout the project PTDC/EMD-EMD/1230/2021 (AneurysmTool) and UIDB/00667/2020 (UNIDEMI) and the support provided by the Brazilian Government funding agencies CAPES, Brazil , FAPERJ, Brazil and CNPq, Brazil . Publisher Copyright: © 2022 The AuthorsThis work presents an out-of-the-box python-based open-source 3D Digital Image Correlation (3D-DIC) software for both in-plane and out-of-plane full-field measurements, denoted by iCorrVision-3D. The software includes an integrated stereo grabber for image acquisition, stereo calibration, numerical stereo correlation and post-processing modules. The main objective is to provide a complete integrated 3D-DIC system for users. All important DIC setting parameters can be easily controlled by the user from an intuitive graphical interface. For instance, the interpolation strategy and correlation techniques that are usually not open for users are available for modifications in iCorrVision-3D. The proposed software can be used in a great number of applications in engineering. Results indicated that the iCorrVision-3D software is robust and accurate in reconstructing the 3D shape of objects and in evaluating the out-of-plane full-field displacement of specimens being tested.publishersversionpublishe