English
Related papers

Related papers: A least-squares functional for joint exit wave rec…

200 papers

Metasurfaces provide a compact, flexible, and reliable solution for controlling the wavefront of light. In imaging systems, micro-lens arrays are integrated with pixel matrices to reduce optical crosstalk, enhance photon collection…

We describe a "spatio-spectral" deconvolution algorithm for wide-band imaging in radio interferometry. In contrast with the existing multi-frequency reconstruction algorithms, the proposed method does not rely on a model of the…

Instrumentation and Methods for Astrophysics · Physics 2016-03-01 André Ferrari , Jérémy Deguignet , Chiara Ferrari , David Mary , Antony Schutz , Oleg Smirnov

We propose an approach based on convex relaxations for certifiably optimal robust multiview triangulation. To this end, we extend existing relaxation approaches to non-robust multiview triangulation by incorporating a truncated least…

Computer Vision and Pattern Recognition · Computer Science 2023-04-06 Linus Härenstam-Nielsen , Niclas Zeller , Daniel Cremers

Physics has played a fundamental role in medicine sciences, specially in imaging diagnostic. Currently, image reconstruction techniques are already taught in Physics courses and there is a growing interest in new potential applications. The…

Physics Education · Physics 2013-02-22 Olavo Henrique Menin , Vanessa Rolnik , Alexandre Souto Martinez

Structured illumination microscopy (SIM) achieves superresolution in fluorescence imaging through patterned illumination and computational image reconstruction, yet current methods require bulky, costly modulation optics and high-precision…

Optics · Physics 2024-04-15 Tamal Roy , Peter T. Brown , Douglas P. Shepherd , Lisa V. Poulikakos

Wave-front sensing from focal plane multiple images is a promising technique for high-contrast imaging systems. However, the wave-front error of an optics system can be properly reconstructed only when it is very small. This paper presents…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Jiangpei Dou , Deqing Ren , Yongtian Zhu

We propose a variational regularisation approach for the problem of template-based image reconstruction from indirect, noisy measurements as given, for instance, in X-ray computed tomography. An image is reconstructed from such measurements…

Optimization and Control · Mathematics 2019-04-02 Lukas F. Lang , Sebastian Neumayer , Ozan Öktem , Carola-Bibiane Schönlieb

Positron emission tomographs (PET) do not measure an image directly. Instead, they measure at the boundary of the field-of-view (FOV) of PET tomograph a sinogram that consists of measurements of the sums of all the counts along the lines…

We introduce a novel optimization algorithm for image recovery under learned sparse and low-rank constraints, which we parameterize as weighted extensions of the $\ell_p^p$-vector and $\mathcal S_p^p$ Schatten-matrix quasi-norms for…

Computer Vision and Pattern Recognition · Computer Science 2023-04-21 Stamatios Lefkimmiatis , Iaroslav Koshelev

In this paper we propose spatial filters for a linear regression model which are based on the minimum-variance pseudo-unbiased reduced-rank estimation (MV-PURE) framework. As a sample application, we consider the problem of reconstruction…

Signal Processing · Electrical Eng. & Systems 2024-08-02 Tomasz Piotrowski , Jan Nikadon , David Gutierrez

We introduce a general framework for the reconstruction of periodic multivariate functions from finitely many and possibly noisy linear measurements. The reconstruction task is formulated as a penalized convex optimization problem, taking…

Optimization and Control · Mathematics 2020-12-02 Julien Fageot , Matthieu Simeoni

We employ ptychography, a phase-retrieval imaging technique, to show experimentally for the first time that a partially coherent high-energy matter (electron) wave emanating from an extended source can be decomposed into a set of mutually…

Mesoscale and Nanoscale Physics · Physics 2017-01-04 S. Cao , P. Kok , P. Li , A. M. Maiden , J. M. Rodenburg

Purpose: To introduce a novel method for the recovery of multi-shot diffusion weighted (MS-DW) images from echo-planar imaging (EPI) acquisitions. Methods: Current EPI-based MS-DW reconstruction methods rely on the explicit estimation of…

Medical Physics · Physics 2016-02-24 Merry Mani , Mathews Jacob , Douglas Kelley , Vincent Magnotta

The beam squint effect, which manifests in different steering matrices in different sub-bands, has been widely considered a challenge in millimeter wave (mmWave) multiinput multi-output (MIMO) channel estimation. Existing methods either…

Signal Processing · Electrical Eng. & Systems 2023-06-21 Le Xu , Lei Cheng , Ngai Wong , Yik-Chung Wu , H. Vincent Poor

This paper provides an analysis of the linearized inverse problem in multifrequency electrical impedance tomography. We consider an isotropic conductivity distribution with a finite number of unknown inclusions with different frequency…

Numerical Analysis · Mathematics 2016-10-06 Giovanni S. Alberti , Habib Ammari , Bangti Jin , Jin-Keun Seo , Wenlong Zhang

We describe a generalized formalism, addressing the fundamental problem of reflection and transmission of complex optical waves at a plane dielectric interface. Our formalism involves the application of generalized operator matrices to the…

Optics · Physics 2023-02-28 Anirban Debnath , Nirmal K. Viswanathan

The inverse conductivity problem aims at determining the unknown conductivity inside a bounded domain from boundary measurements. In practical applications, algorithms based on minimizing a regularized residual functional subject to PDE…

Numerical Analysis · Mathematics 2025-10-02 Lefu Cai , Zhixin Liu , Minghui Song , Xianchao Wang

Alternating projection onto convex sets (POCS) provides an iterative procedure to find a signal that satisfies two or more convex constraints when the sets intersect. For nonintersecting constraints, the method of simultaneous projections…

Image and Video Processing · Electrical Eng. & Systems 2026-02-19 Albert R. Yu , Robert J. Marks , Keith E. Schubert , Charles Baylis , Austin Egbert , Adam Goad , Sam Haug

In a scanning transmission electron microscope (STEM), producing a high-resolution image generally requires an electron beam focused to the smallest point possible. However, the magnetic lenses used to focus the beam are unavoidably…

It has been argued that in atomic-resolution transmission electron microscopy (TEM) of sparse weakly scattering structures, such as small biological molecules, multiple electron scattering usually has only a small effect, while the…

Optics · Physics 2021-11-16 T. E. Gureyev , H. M. Quiney , A. Kozlov , D. M. Paganin , G. Schmalz , L. J. Allen