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Related papers: Electron Fourier ptychography for phase reconstruc…

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This paper discusses the reconstruction of partially sampled spectrum-images to accelerate the acquisition in scanning transmission electron microscopy (STEM). The problem of image reconstruction has been widely considered in the literature…

Image and Video Processing · Electrical Eng. & Systems 2020-02-05 Etienne Monier , Thomas Oberlin , Nathalie Brun , Xiaoyan Li , Marcel Tencé , Nicolas Dobigeon

Measurements of coherent radiation at accelerators typically give the absolute value of the beam profile Fourier transform but not its phase. Phase reconstruction techniques such as Hilbert transform or Kramers Kronig reconstruction are…

Accelerator Physics · Physics 2015-12-07 Nicolas Delerue , Joanna Barros , Oleg Bezshyyko , Vitalii Khodnevych

Measurements of coherent radiation at accelerators typically give the absolute value of the beam profile Fourier transform but not its phase. Phase reconstruction techniques such as Hilbert transform or Kramers Kronig reconstruction are…

In recent work [P. Grohs and M. Rathmair. Stable Gabor Phase Retrieval and Spectral Clustering. Communications on Pure and Applied Mathematics (2018)] the instabilities of the Gabor phase retrieval problem, i.e., the problem of…

Functional Analysis · Mathematics 2019-03-05 Philipp Grohs , Martin Rathmair

The Fractional Fourier Transform (FRT) corresponds to an arbitrary-angle rotation in the phase space, e.g. the time-frequency (TF) space, and generalizes the fundamentally important Fourier Transform. FRT applications range from classical…

Optics · Physics 2024-03-06 Michał Lipka , Michał Parniak

Faraday tomography offers crucial information on the magnetized astronomical objects, such as quasars, galaxies, or galaxy clusters, by observing its magnetoionic media. The observed linear polarization spectrum is inverse Fourier…

Instrumentation and Methods for Astrophysics · Physics 2020-11-24 Suchetha Cooray , Tsutomu T. Takeuchi , Takuya Akahori , Yoshimitsu Miyashita , Shinsuke Ideguchi , Keitaro Takahashi , Kiyotomo Ichiki

Iterative projection algorithms are successfully being used as a substitute of lenses to recombine, numerically rather than optically, light scattered by illuminated objects. Images obtained computationally allow aberration-free…

Optics · Physics 2007-05-23 S. Marchesini

Phase retrieval consists in the recovery of an unknown signal from phaseless measurements of its usually complex-valued Fourier transform. Without further assumptions, this problem is notorious to be severe ill posed such that the recovery…

Information Theory · Computer Science 2023-01-19 Robert Beinert , Saghar Rezaei

We report the development of deep learning coherent electron diffractive imaging at sub-angstrom resolution using convolutional neural networks (CNNs) trained with only simulated data. We experimentally demonstrate this method by applying…

Materials Science · Physics 2022-04-19 Dillan J. Chang , Colum M. O'Leary , Cong Su , Salman Kahn , Alex Zettl , Jim Ciston , Peter Ercius , Jianwei Miao

We study the problem of recovering the phase from magnitude measurements; specifically, we wish to reconstruct a complex-valued signal x of C^n about which we have phaseless samples of the form y_r = |< a_r,x >|^2, r = 1,2,...,m (knowledge…

Information Theory · Computer Science 2016-11-17 Emmanuel Candes , Xiaodong Li , Mahdi Soltanolkotabi

Microscopic fringe projection profilometry is a powerful 3D measurement technique with a theoretical measurement accuracy better than one micron provided that the measured targets can be imaged with good fringe visibility. However,…

Image and Video Processing · Electrical Eng. & Systems 2019-06-26 Yan Hu , Qian Chen , Yichao Liang , Shijie Feng , Tianyang Tao , Chao Zuo

We introduce a framework for the reconstruction of the amplitude, phase and polarisation of an optical vector-field using calibration measurements acquired by an imaging device with an unknown linear transformation. By incorporating…

An extension may be proposed to the intensity interferometer of Hanbury Brown and Twiss to provide the Fourier phase measurement by the use of third-order intensity correlations. It is well known that interferometric reconstruction of…

Astrophysics · Physics 2008-06-14 B. E. Zhilyaev

To study the fundamental physics of complex multiphase flow systems using advanced measurement techniques, especially the electrical capacitance tomography (ECT) approach, this article carries out an initial literature review of the ECT…

Computer Vision and Pattern Recognition · Computer Science 2015-10-16 Kezhi Li

Ptychography is an imaging technique which involves a sample being illuminated by a coherent, localized probe of illumination. When the probe interacts with the sample, the light is diffracted and a diffraction pattern is detected. Then the…

Numerical Analysis · Mathematics 2023-01-31 Mark Iwen , Michael Perlmutter , Mark Philip Roach

Instruments to visualize transient structural changes of inhomogeneous materials on the nanometer scale with atomic spatial and temporal resolution are demanded to advance materials science, bioscience, and fusion sciences. One such…

Accelerator Physics · Physics 2017-03-20 X. Shen , R. K. Li , U. Lundström , T. J. Lane , A. H. Reid , S. P. Weathersby , X. J. Wang

High-resolution imaging in the terahertz (THz) spectral range remains fundamentally constrained by the limited numerical apertures of currently existing state-of-the-art imagers, which restricts its applicability across many fields, such as…

Phase retrieval in optical imaging refers to the recovery of a complex signal from phaseless data acquired in the form of its diffraction patterns. These patterns are acquired through a system with a coherent light source that employs a…

We address the problem of signal reconstruction from intensity measurements with respect to a measurement frame. This non-convex inverse problem is known as phase retrieval. The case considered in this paper concerns phaseless measurements…

Functional Analysis · Mathematics 2019-02-13 Goetz E. Pfander , Palina Salanevich

Electron scattering on liquid samples has been enabled recently by the development of ultrathin liquid sheet technologies. The data treatment of liquid-phase electron scattering has been mostly reliant on methodologies developed for gas…