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Optical focusing through/inside scattering media, like multimode fiber and biological tissues, has significant impact in biomedicine yet considered challenging due to strong scattering nature of light. Previously, promising progress has…

We describe a new algorithm for reconstruction of Differential Emission Measures (DEMs) in the solar corona. Although a number of such algorithms currently exist, they can have difficulty converging for some cases, and can be complex, slow,…

Solar and Stellar Astrophysics · Physics 2020-12-11 Joseph Plowman , Amir Caspi

Metaoptics are thin, planar surfaces consisting of many subwavelength optical resonators that can be designed to simultaneously control the amplitude, phase, and polarization to arbitrarily shape an optical wavefront much in the same manner…

A novel framework to construct an efficient sensing (measurement) matrix, called mixed adaptive-random (MAR) matrix, is introduced for directly acquiring a compressed image representation. The mixed sampling (sensing) procedure hybridizes…

Information Theory · Computer Science 2015-04-07 Jun Yang , Wei E. I. Sha , Hongyang Chao , Zhu Jin

Inverse design of metasurfaces for the joint optimization of optical modulation and algorithmic decoding in computational optics presents significant challenges, especially in applications such as hyperspectral imaging. We introduce a…

Image and Video Processing · Electrical Eng. & Systems 2025-10-28 Rongzhou Chen , Haitao Nie , Shuo Zhu , Yaping Zhao , Chutian Wang , Edmund Y. Lam

Recent advances in depth sensing technologies allow fast electronic maneuvering of the laser beam, as opposed to fixed mechanical rotations. This will enable future sensors, in principle, to vary in real-time the sampling pattern. We…

Computer Vision and Pattern Recognition · Computer Science 2022-05-23 Ilya Tcenov , Guy Gilboa

We propose an iterative solution method for the 3D high-frequency Helmholtz equation that exploits a contour integral formulation of spectral projectors. In this framework, the solution in certain invariant subspaces is approximated by…

Numerical Analysis · Mathematics 2018-11-30 Xiao Liu , Yuanzhe Xi , Yousef Saad , Maarten V. de Hoop

Undersampling the k-space during MR acquisitions saves time, however results in an ill-posed inversion problem, leading to an infinite set of images as possible solutions. Traditionally, this is tackled as a reconstruction problem by…

Image and Video Processing · Electrical Eng. & Systems 2022-02-10 Kerem C. Tezcan , Neerav Karani , Christian F. Baumgartner , Ender Konukoglu

A novel and highly efficient computational framework for reconstructing binary-type images suitable for models of various complexity seen in diverse biomedical applications is developed and validated. Efficiency in computational speed and…

Optimization and Control · Mathematics 2024-02-09 Paul R. Arbic , Vladislav Bukshtynov

To reduce scanning time and/or improve spatial/temporal resolution in some MRI applications, parallel MRI (pMRI) acquisition techniques with multiple coils acquisition have emerged since the early 1990s as powerful 3D imaging methods that…

Optimization and Control · Mathematics 2009-09-03 Lotfi Chaari , Jean-Christophe Pesquet , Philippe Ciuciu , Amel Benazza-Benyahia

Computed Tomography (CT) reconstruction of objects with cylindrical symmetry can be performed with a single projection. When the measured rays are parallel, and the axis of symmetry is perpendicular to the optical axis, the data can be…

Medical Physics · Physics 2024-10-15 Kyle M. Champley , Ibrahim Oksuz , Matthew G. Bisbee , Joseph W. Tringe , Brian Maddox

In this letter, we present a novel low-complexity adaptive beamforming technique using a stochastic gradient algorithm to avoid matrix inversions. The proposed method exploits algorithms based on the maximum entropy power spectrum (MEPS) to…

Information Theory · Computer Science 2020-12-29 S. Mohammadzadeh , V. H. Nascimento , R. C. de Lamare

Mathematical methods of step-by-step and combined shifts are proposed for experimental data processing to reconstruct the measuring system impulse response distorted by shift-invariant blur. Proposed methods base on direct non-blind…

Signal Processing · Electrical Eng. & Systems 2019-01-24 Andrey V. Novikov-Borodin

Inverse ellipsometry, i.e., reconstructing optical constants and film thickness from the measured phase difference $\Delta$ and amplitude ratio $\Psi$, is a fundamentally ill-posed problem. Traditional solutions rely on slow, expert-driven…

Machine Learning · Computer Science 2026-03-20 Yiming Ma , Jianzhi Teng , Xinjie Li , Xin Sun , Zhiyong Wang , Yuzhou Song , Lionel Z. Wang , Bin Chen

X-ray ptychography is a cutting edge imaging technique providing ultra-high spatial resolutions. In ptychography, phase retrieval, i.e., the recovery of a complex valued signal from intensity-only measurements, is enabled by exploiting a…

Image and Video Processing · Electrical Eng. & Systems 2022-09-14 Felix Wittwer , Peter Modregger

This paper proposes a reduced-rank scheme for adaptive beamforming based on the constrained joint iterative optimization of filters. We employ this scheme to devise two novel reduced-rank adaptive algorithms according to the constant…

Information Theory · Computer Science 2013-03-08 Lei Wang , Rodrigo C. de Lamare

Recent advances in 3D vision have demonstrated the strengths of photometric bundle adjustment. By directly minimizing reprojected pixel errors, instead of geometric reprojection errors, such methods can achieve sub-pixel alignment accuracy…

Computer Vision and Pattern Recognition · Computer Science 2017-04-25 Christopher Ham , Simon Lucey , Surya Singh

Inverse problems in imaging are typically ill-posed and are usually solved by employing regularized optimization techniques. The usage of appropriate constraints can restrict the solution space, thus making it feasible for a reconstruction…

Image and Video Processing · Electrical Eng. & Systems 2025-11-14 Jasleen Birdi , Tamal Majumder , Debanjan Halder , Muskan Kularia , Kedar Khare

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

Real-time magnetic resonance imaging (MRI) methods generally shorten the measuring time by acquiring less data than needed according to the sampling theorem. In order to obtain a proper image from such undersampled data, the reconstruction…

Numerical Analysis · Mathematics 2013-12-05 Housen Li , Markus Haltmeier , Shuo Zhang , Jens Frahm , Axel Munk