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Holographic coherent X-ray imaging enables nanoscale imaging of biological cells and tissues, rendering both phase and absorption contrast, i.e. real and imaginary parts of the refractive index. Unlike the standard model, which assumes a…

Analysis of PDEs · Mathematics 2026-05-29 Thorsten Hohage , Milad Karimi , Björn Müller

Conventional dual-frequency fringe projection algorithm often suffers from phase unwrapping failure when the frequency ratio between the high frequency and the low one is too large. Zhang et.al. proposed an enhanced two-frequency…

Computer Vision and Pattern Recognition · Computer Science 2017-06-28 Guangliang Du , Minmin Wang , Canlin Zhou , Shuchun Si , Hui Li , Zhenkun Lei , Yanjie Li

In this lecture, we describe a number of advanced gain calibration techniques. In particular, self-calibration is an important tool in interferometric imaging at all wavelengths. It allows the observer to determine and remove residual phase…

Instrumentation and Methods for Astrophysics · Physics 2018-05-15 Crystal L. Brogan , Todd R. Hunter , Ed B. Fomalont

A critical challenge in measuring the power spectrum of 21cm emission from cosmic reionization is compensating for the frequency dependence of an interferometer's sampling pattern, which can cause smooth-spectrum foregrounds to appear…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Aaron R. Parsons , Jonathan C. Pober , James E. Aguirre , Christopher L. Carilli , Daniel C. Jacobs , David F. Moore

Portrait harmonization aims to composite a subject into a new background, adjusting its lighting and color to ensure harmony with the background scene. Existing harmonization techniques often only focus on adjusting the global color and…

Computer Vision and Pattern Recognition · Computer Science 2024-04-09 Mengwei Ren , Wei Xiong , Jae Shin Yoon , Zhixin Shu , Jianming Zhang , HyunJoon Jung , Guido Gerig , He Zhang

Starting from an elementary model and refining it to take into account more realistic effects, we discuss the limitations and advantages of matter-wave interferometry in different configurations. We focus on the possibility to apply this…

Quantum Physics · Physics 2015-09-02 Simone Sala , Fabrizio Castelli , Marco Giammarchi , Stefano Siccardi , Stefano Olivares

An inverse source reconstruction (ISR) based 3-D near-field (NF) passive radar microwave imaging method utilizing modulated signals is presented. The modulated signals from a non-cooperative transmitter are scattered by the targets of…

Image and Video Processing · Electrical Eng. & Systems 2026-05-06 Quanfeng Wang , Alexander H. Paulus , Thomas F. Eibert

Biological soft tissues encountered in clinical and pre-clinical imaging mainly consist of light element atoms, and their composition is nearly uniform with little density variation. Thus, x-ray attenuation imaging suffers from low image…

Medical Physics · Physics 2011-06-28 Wenxiang Cong , Atsushi Momose , Ge Wang

Context. The next generation of space-borne instruments dedicated to the direct detection of exoplanets requires unprecedented levels of wavefront control precision. Coronagraphic wavefront sensing techniques for these instruments must…

Instrumentation and Methods for Astrophysics · Physics 2018-07-20 Olivier Herscovici-Schiller , Laurent M. Mugnier , Pierre Baudoz , Raphaël Galicher , Jean-François Sauvage , Baptiste Paul

Phase unwrapping is a key problem in many coherent imaging systems, such as synthetic aperture radar (SAR) interferometry. A general formulation for redundant integration of finite differences for phase unwrapping (Costantini et al., 2010)…

Other Computer Science · Computer Science 2018-05-04 Ravi Lanka

High contrast matter-wave interferometry is essential in various fundamental quantum mechanical experiments as well as for technical applications. Thereby, contrast and sensitivity are typically reduced by decoherence and dephasing effects.…

Quantum Physics · Physics 2015-11-18 Andreas Günther , Alexander Rembold , Georg Schütz , Alexander Stibor

We outline some basics of imaging using both fully-coherent and partially-coherent X-ray beams, with an emphasis on phase-contrast imaging. We open with some of the basic notions of X-ray imaging, including the vacuum wave equations and the…

Image and Video Processing · Electrical Eng. & Systems 2021-11-16 David M. Paganin , Daniele Pelliccia

This paper presents an innovative in-pixel contrast enhancement circuit that performs image processing directly within the pixel circuit. The circuit can be tuned for different modes of operation. In foreground enhancement mode, it…

Computer Vision and Pattern Recognition · Computer Science 2024-10-24 Md Rahatul Islam Udoy , Md Mazharul Islam , Elijah Johnson , Ahmedullah Aziz

X-ray micro tomography is a non-destructive, three-dimensional inspection technique applied across a vast range of fields and disciplines, ranging from research to industrial, encompassing engineering, biology and medical research.…

Space-based coronagraphs for future earth-like planet detection will require focal plane wavefront control techniques to achieve the necessary contrast levels. These correction algorithms are iterative and the control methods require an…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Tyler D. Groff , N. Jeremy Kasdin

Recovering images from optical interferometric observations is one of the major challenges in the field. Unlike the case of observations at radio wavelengths, in the optical the atmospheric turbulence changes the phases on a very short time…

We report on a new x-ray imaging method, which combines the high spatial resolution of coherent diffraction imaging with the ability of dark field microscopy to map grains within thick polycrystalline specimens. An x-ray objective serves to…

Instrumentation and Detectors · Physics 2020-07-15 Anders Filsøe Pedersen , Virginie Chamard , Carsten Detlefs , Tao Zhou , Dina Carbone , Henning Friis Poulsen

The single sideband (SSB) framework of analytical electron ptychography can account for the presence of residual geometrical aberrations induced by the probe-forming lens. However, the accuracy of this aberration correction method is highly…

In many areas of imaging science, it is difficult to measure the phase of linear measurements. As such, one often wishes to reconstruct a signal from intensity measurements, that is, perform phase retrieval. In this paper, we provide a…

Information Theory · Computer Science 2013-09-13 Boris Alexeev , Afonso S. Bandeira , Matthew Fickus , Dustin G. Mixon

X-ray dark-field imaging creates a representation of the sample where contrast is generated by subresolution features within the volume under inspection. These are detected by a local measurement of the radiation field's angular…