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We retrieve depth information (moments) of an object using partially coherent fields and defocus induced holographic contrast. Our analysis leads to a form of tomography that does not require sample or source rotation. The tomography method…

Optics · Physics 2016-06-22 M. A. Beltran , T. C. Petersen , M. J. Kitchen , D. M. Paganin

The ill-posed problem of phase retrieval in optics, using one or more intensity measurements, has a multitude of applications using electromagnetic or matter waves. Many phase retrieval algorithms are computed on pixel arrays using discrete…

Image and Video Processing · Electrical Eng. & Systems 2022-09-21 J. A. Pollock , K. S. Morgan , L. C. P. Croton , M. K. Croughan , G. Ruben , N. Yagi , H. Sekiguchi , M. J. Kitchen

We derive an original direct imaging method of an object. It is based on topological derivatives, and aims at inverting the amplitude of waves that are retropropagated after laser illuminations.

Numerical Analysis · Mathematics 2010-12-02 Jean-Baptiste Bellet , Gérard Berginc

In radio astronomy, holography is a commonly used technique to create an image of the electric field distribution in the aperture of a dish antenna. The image is used to detect imperfections in the reflector surface. Similarly, holography…

Instrumentation and Methods for Astrophysics · Physics 2021-06-09 U. Kiefner , R. B. Wayth , D. B. Davidson , M. Sokolowski

Optoacoustic tomography image reconstruction has been a problem of interest in recent years. By exploiting the exceptional generative power of the recently proposed diffusion models we consider a scheme which is based on a conditional…

Image and Video Processing · Electrical Eng. & Systems 2024-11-26 Martin G. Gonzalez , Matias Vera , Leonardo Rey Vega

Many complex systems can be reduced to their key components through spectrally decomposing matrices that capture their dynamics. These matrices can in turn be constructed from data, often by least-squares fitting: examples of algorithms to…

Numerical Analysis · Mathematics 2026-05-18 Caroline Wormell

Quantitative phase imaging has become a topic of considerable interest in the microscopy community. We have recently described one such technique based on the use of a partitioned detection aperture, which can be operated in a single shot…

Optics · Physics 2015-10-20 Roman Barankov , Jean-Charles Baritaux , Jerome Mertz

Reconfigurable reflectors have a significant potential in future telecommunication systems, and approaches to the design and realization of full and tunable reflection control are now actively studied. Reflectarrays, being the classical…

Applied Physics · Physics 2023-06-28 Fu Liu , Do-Hoon Kwon , Sergei A. Tretyakov

We develop and implement a compressive reconstruction method for tomographic recovery of refractive index distribution for weakly attenuating objects in a microfocus X-ray system. This is achieved through the development of a discretized…

Efficient imaging of biomolecules, 2D materials and electromagnetic fields depends on retrieval of the phase of transmitted electrons. We demonstrate a method to measure phase in a scanning transmission electron microscope using a…

Analysis of signals defined on complex topologies modeled by graphs is a topic of increasing interest. Signal decomposition plays a crucial role in the representation and processing of such information, in particular, to process graph…

Signal Processing · Electrical Eng. & Systems 2025-02-18 Harry H. Behjat , Carl-Fredrik Westin , Rik Ossenkoppele , Dimitri Van De Ville

The scattering transform is a non-linear signal representation method based on cascaded wavelet transform magnitudes. In this paper we introduce phase scattering, a novel approach where we use phase derivatives in a scattering procedure. We…

Sound · Computer Science 2024-07-09 Daniel Haider , Peter Balazs , Nicki Holighaus

We consider the imaging problem of the reconstruction of a three-dimensional object via optical diffraction tomography under the assumptions of the Born approximation. Our focus lies in the situation that a rigid object performs an…

Numerical Analysis · Mathematics 2024-07-11 Robert Beinert , Michael Quellmalz

Ptychography is a computational method of microscopy that recovers high-resolution transmission images of samples from a series of diffraction patterns. While conventional phase retrieval algorithms can iteratively recover the images, they…

Image and Video Processing · Electrical Eng. & Systems 2024-10-24 Ryuma Nakahata , Shehtab Zaman , Mingyuan Zhang , Fake Lu , Kenneth Chiu

This paper addresses the challenge of spectral-spatial feature extraction for hyperspectral image classification by introducing a novel tensor-based framework. The proposed approach incorporates circular convolution into a tensor structure…

Computer Vision and Pattern Recognition · Computer Science 2024-12-10 Yuemei Ren , Liang Liao , Stephen John Maybank , Yanning Zhang , Xin Liu

We describe a technique for improving the response of a telescope chopping secondary mirror assembly by using a signal processing method based on the Lucy deconvolution technique. This technique is general and could be used for any systems,…

Astrophysics · Physics 2009-11-10 Martin Houde , Lynn C. Holt , Hiroshige Yoshida , Patrick M. Nelson

Learned progressive image compression is gaining momentum as it allows improved image reconstruction as more bits are decoded at the receiver. We propose a progressive image compression method in which an image is first represented as a…

Computer Vision and Pattern Recognition · Computer Science 2025-01-13 Alberto Presta , Enzo Tartaglione , Attilio Fiandrotti , Marco Grangetto , Pamela Cosman

We present a simple but effective method to extract the reflectivity spectra from the interference signals with a large NA white light interferometry. Numerical simulations and experiments have demonstrated the effectiveness of our method.…

Optics · Physics 2025-03-11 Cheng Chen , Lixuan Xu , Rong Su

Fourier Ptychography is a recently proposed imaging technique that yields high-resolution images by computationally transcending the diffraction blur of an optical system. At the crux of this method is the phase retrieval algorithm, which…

Computer Vision and Pattern Recognition · Computer Science 2018-05-10 Lokesh Boominathan , Mayug Maniparambil , Honey Gupta , Rahul Baburajan , Kaushik Mitra

The problem of phase retrieval is a classic one in optics and arises when one is interested in recovering an unknown signal from the magnitude (intensity) of its Fourier transform. While there have existed quite a few approaches to phase…

Information Theory · Computer Science 2015-10-28 Kishore Jaganathan , Yonina C. Eldar , Babak Hassibi
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