Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
29
result(s) for
"Holography Computer programs."
Sort by:
Digital holography
This book presents a substantial description of the principles and applications of digital holography.
The first part of the book deals with mathematical basics and the linear filtering theory necessary to approach the topic. The next part describes the fundamentals of diffraction theory and exhaustively details the numerical computation of diffracted fields using FFT algorithms. A thorough presentation of the principles of holography and digital holography, including digital color holography, is proposed in the third part.
A special section is devoted to the algorithms and methods for the numerical reconstruction of holograms. There is also a chapter devoted to digital holographic interferometry with applications in holographic microscopy, quantitative phase contrast imaging, multidimensional deformation investigations, surface shape measurements, fluid mechanics, refractive index investigations, synthetic aperture imaging and information encrypting.
Keys so as to understand the differences between digital holography and speckle interferometry and examples of software for hologram reconstructions are also treated in brief.
eBook
Application of holography and augmented reality based technology to visualize the internal structure of the dental root – a proof of concept
Background
The Augmented Reality (AR) blends digital information with the real world. Thanks to cameras, sensors, and displays it can supplement the physical world with holographic images. Nowadays, the applications of AR range from navigated surgery to vehicle navigation.
Development
The purpose of this feasibility study was to develop an AR holographic system implementing Vertucci’s classification of dental root morphology to facilitate the study of tooth anatomy. It was tailored to run on the AR HoloLens 2 (Microsoft) glasses. The 3D tooth models were created in Autodesk Maya and exported to Unity software. The holograms of dental roots can be projected in a natural setting of the dental office. The application allowed to display 3D objects in such a way that they could be rotated, zoomed in/out, and penetrated. The advantage of the proposed approach was that students could learn a 3D internal anatomy of the teeth without environmental visual restrictions.
Conclusions
It is feasible to visualize internal dental root anatomy with AR holographic system. AR holograms seem to be attractive adjunct for learning of root anatomy.
Journal Article
HoToPy: a toolbox for X‐ray holo‐tomography in Python
We present a Python toolbox for holographic and tomographic X‐ray imaging. It comprises a collection of phase retrieval algorithms for the deeply holographic and direct contrast imaging regimes, including non‐linear approaches and extended choices of regularization, constraint sets and optimizers, all implemented with a unified and intuitive interface. Moreover, it features auxiliary functions for (tomographic) alignment, image processing and simulation of imaging experiments. The capability of the toolbox is illustrated by an example of a catalytic nanoparticle, imaged in the deeply holographic regime at the `GINIX' instrument of the P10 beamline at the PETRA III storage ring (DESY, Hamburg, Germany). Due to its modular design, the toolbox can be used for algorithmic development and benchmarking in a lean and flexible manner, or be interfaced and integrated in the reconstruction pipeline of other synchrotron or X‐ray free‐electron laser instruments for phase imaging based on propagation. We present HoToPy, a toolbox for X‐ray holo‐tomography in Python. It offers state‐of‐the‐art phase retrieval methods for synchrotron and laboratory sources as well as tomographic reconstruction and alignment methods.
Journal Article
New methods of removing debris and high-throughput counting of cyst nematode eggs extracted from field soil
The soybean cyst nematode (SCN), Heterodera glycines, is the most damaging pathogen of soybeans in the United States. To assess the severity of nematode infestations in the field, SCN egg population densities are determined. Cysts (dead females) of the nematode must be extracted from soil samples and then ground to extract the eggs within. Sucrose centrifugation commonly is used to separate debris from suspensions of extracted nematode eggs. We present a method using OptiPrep as a density gradient medium with improved separation and recovery of extracted eggs compared to the sucrose centrifugation technique. Also, computerized methods were developed to automate the identification and counting of nematode eggs from the processed samples. In one approach, a high-resolution scanner was used to take static images of extracted eggs and debris on filter papers, and a deep learning network was trained to identify and count the eggs among the debris. In the second approach, a lensless imaging setup was developed using off-the-shelf components, and the processed egg samples were passed through a microfluidic flow chip made from double-sided adhesive tape. Holographic videos were recorded of the passing eggs and debris, and the videos were reconstructed and processed by custom software program to obtain egg counts. The performance of the software programs for egg counting was characterized with SCN-infested soil collected from two farms, and the results using these methods were compared with those obtained through manual counting.
Journal Article
DryMass: handling and analyzing quantitative phase microscopy images of spherical, cell-sized objects
Background
Quantitative phase imaging (QPI) is an established tool for the marker-free classification and quantitative characterization of biological samples. For spherical objects, such as cells in suspension, microgel beads, or liquid droplets, a single QPI image is sufficient to extract the radius and the average refractive index. This technique is invaluable, as it allows the characterization of large sample populations at high measurement rates. However, until now, no universal software existed that could perform this type of analysis. Besides the choice of imaging modality and the variety in imaging software, the main difficulty has been to automate the entire analysis pipeline from raw data to ensemble statistics.
Results
We present DryMass, a powerful tool for QPI that covers all relevant steps from loading experimental data (multiple file formats supported), computing the phase data (built-in, automated hologram analysis), performing phase background corrections (offset, tilt, second order polynomial) to fitting scattering models (light projection, Rytov approximation, Mie simulations) to spherical phase objects for the extraction of dry mass, radius, and average refractive index. The major contribution of DryMass is a user-convenient, reliable, reproducible, and automated analysis pipeline for an arbitrary number of QPI datasets of arbitrary sizes.
Conclusion
DryMass is a leap forward for data analysis in QPI, as it not only makes it easier to visualize raw QPI data and reproduce previous results in the field, but it also opens up QPI analysis to users without a background in programming or phase imaging.
Journal Article
Strain Measurement in Single Crystals by 4D-ED
A new method is presented to measure strain over a large area of a single crystal. The 4D-ED data are collected by recording a 2D diffraction pattern at each position in the 2D area of the TEM lamella scanned by the electron beam of STEM. Data processing is completed with a new computer program (available free of charge) that runs under the Windows operating system. Previously published similar methods are either commercial or need special hardware (electron holography) or are based on HRTEM, which involves limitations with respect to the size of the field of view. All these limitations are overcome by our approach. The presence of defects results in small local changes in orientation that change the subset of experimentally available diffraction spots in the individual patterns. Our method is based on a new principle, namely fitting a lattice to (a subset of) measured diffraction spots to improve the precision of the measurement. Although a spot to be measured may be missing in some of the patterns even the missing spot can be precisely measured by the lattice determined from the available spots. Application is exemplified by heavily boron-doped silicon with intended usage as a low-temperature superconductor in qubits.
Journal Article
A Toolbox for Isophase-Curvature Guided Computation of Metrology Holograms
We describe the algorithmic foundations of an open-source numerical toolbox, written in the Octave language, for the creation of computer-generated binary and multi-level holograms used in interferometric form error measurements of complex aspheric and free-form precision surfaces and wavefronts. In a typical measurement setup for this type of surface, a hologram is used to generate a test wavefront that has the design shape of the surface, which is then compared to a fabricated part using an imaging laser interferometer. The optical function of the hologram in the measurement is generally modeled with optical ray-tracing software and it can be encapsulated by a scalar optical phase function φ : R2 →R. The toolbox converts phase functions into equivalent binary holograms that generate the desired test wavefronts for an interferometric form error measurement. The algorithms in this toolbox take advantage of the relationship between the local properties of phase functions and the local geometry (curvature) of isophase lines. It forms the core of an effcient algorithm for the computation of optical holograms. Holograms are created in a format that can be processed by most laser-or e-beam lithography systems. While the toolbox is chiefy aimed at the creation of hologram layouts needed for measurements of precision surfaces and wavefronts, we show that the isophase-following algorithm is easily extended to phase functions with singularities and discontinuities. Such phase functions result in holograms with zone bifurcation and they can be used to generate helical wavefronts. Light beams with helical wavefronts have applications beyond surface and wavefront metrology. The toolbox also includes a family of functions for the effcient estimation and evaluation of Zernike polynomials, which are widely used in optical applications.
Journal Article
Hands-On Accelerator Physics Using MATLAB
Hands-On Accelerator Physics Using MATLAB®, Second Edition, provides a broad introduction into the physics and the technology of particle accelerators from synchrotron light sources to high-energy colliders. It covers the design of beam optics, magnets, and radio-frequency systems, followed by a discussion of beam instrumentation and correction algorithms. Later chapters deal with the interaction of beams with targets, the emission of synchrotron radiation, and intensity limitations. Chapters discussing running and future accelerators round up the presentation. Theoretical concepts and the design of key components are explained with the help of MATLAB code. Practical topics, such as beam size measurements, magnet construction and measurements, and radio-frequency measurements are explored in student labs that do not require access to an accelerator. This unique approach provides a look at what goes on \"\"under the hood\"\" inside modern accelerators and presents readers with the tools to perform their independent investigations on the computer or in student labs. This book will be of interest to graduate students, post-graduate researchers studying accelerator physics, as well as engineers entering the field. The second edition features a new chapter on future accelerators and several new sections on polarization, neutrino beams, testing of superconducting cavities, and matching in longitudinal phase space, among others. The MATLAB code was updated to be consistent with the recent release of R2024a. All code is available from the book’s GitHub site at https://github.com/volkziem/HandsOnAccelerators2nd. Key features: Provides a broad introduction into physics of particle accelerators from synchrotron light sources to high-energy colliders. Discusses technical subsystems, including magnets, radio-frequency engineering, instrumentation and diagnostics, correction of imperfections, control, vacuum, and cryogenics. Illustrates key concepts with sample code in MATLAB.
eBook
Product Authentication Using QR Codes: A Mobile Application to Combat Counterfeiting
Counterfeiting is one of the biggest challenges for the authenticity of genuine products. An estimated average of 8–9 % trade consists of counterfeit goods that create a loss of revenue. To combat this situation, the product manufacturers use hologram and barcodes. The issue of genuine product remains the primary challenge in the market. With emerging trends in mobile and wireless technology, Quick Response (QR) codes provide a robust technique to fight the practice of counterfeiting the products. Apart from being used extensively in marketing and information transfer applications, the QR codes and encrypted QR codes are primarily used in security and privacy applications. Many web applications use QR codes for secure login where the user need not remember his/her login ID and password. The encrypted unique user ID is verified at the server using QR codes. Our proposed approach uses QR codes based on 2-dimensional codes (such as 19 Aztec, Data Matrix, etc.) to authenticate the product. This approach simplifies the size of QR code, and minimizes the complexity of encoding and decoding in QR code.
Journal Article