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Related papers: MEM_GE: a new maximum entropy method for image rec…

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Imaging interferometric data in radio astronomy requires the use of non-linear algorithms that rely on different assumptions on the source structure and may produce non-unique results. This is especially true for Very Long Baseline…

Instrumentation and Methods for Astrophysics · Physics 2024-01-19 A. Mus , I. Martí-Vidal

The reconstruction of images from a small number of projections using the maximum-entropy method (MEM) with the Shannon entropy is considered. MEM provides higher-quality image reconstruction for sources with extended components than the…

Astrophysics · Physics 2008-11-26 Anisa T. Bajkova

The maximum entropy method (MEM) is a well known deconvolution technique in radio-interferometry. This method solves a non-linear optimization problem with an entropy regularization term. Other heuristics such as CLEAN are faster but highly…

Instrumentation and Methods for Astrophysics · Physics 2022-10-27 M. Cárcamo , P. Román , S. Casassus , V. Moral , F. R. Rannou

An image restoration approach based on a Bayesian maximum entropy method (MEM) has been applied to a radiological image deconvolution problem, that of reduction of geometric blurring in magnification mammography. The aim of the work is to…

Medical Physics · Physics 2009-11-11 A Jannetta , J C Jackson , C J Kotre , I P Birch , K J Robson , R Padgett

Wavelet functions allow the sparse and efficient representation of a signal at different scales. Recently the application of wavelets to the denoising of maps of cosmic microwave background (CMB) fluctuations has been proposed. The…

Astrophysics · Physics 2009-11-07 Klaus Maisinger , M. P. Hobson , A. N. Lasenby

This paper is concerned with the image reconstruction problem when the measured data are solar hard X-ray modulation profiles obtained from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI)} instrument. Our goal is to…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Federico Benvenuto , Richard Schwartz , Michele Piana , Anna Maria Massone

We present a new algorithm, called Multiresolution Regularized Expectation Maximization (MREM), for the reconstruction of gamma-ray intensity maps from COMPTEL data. The algorithm is based on the iterative Richardson-Lucy scheme to which we…

We have developed a technique to map the three-dimensional structure of the local interstellar medium using a maximum entropy reconstruction technique. A set of column densities N to stars of known distance can in principle be used to…

Astrophysics · Physics 2009-10-31 John S. Arabadjis , Joel N. Bregman

This paper introduces a multiscale maximum entropy (MSME) algorithm for image restoration of the Hard X-ray Modulation Telescope (HXMT), which is a collimated scan X-ray satellite mainly devoted to a sensitive all-sky survey and pointed…

Instrumentation and Methods for Astrophysics · Physics 2016-06-03 Ju Guan , Li-Ming Song , Zhuo-Xi Huo

Image deblurring is a notoriously challenging ill-posed inverse problem. In recent years, a wide variety of approaches have been proposed based upon regularization at the level of the image or on techniques from machine learning. We propose…

Computer Vision and Pattern Recognition · Computer Science 2020-10-22 Gabriel Rioux , Rustum Choksi , Tim Hoheisel , Pierre Marechal , Christopher Scarvelis

Radio polarisation images of the jets of Active Galactic Nuclei (AGN) can provide a deep insight into the launching and collimation mechanisms of relativistic jets. However, even at VLBI scales, resolution is often a limiting factor in the…

Astrophysics of Galaxies · Physics 2016-09-07 Colm P. Coughlan , Denise C. Gabuzda

Resonant inelastic x-ray scattering (RIXS) has become a powerful tool in the study of the electronic structure of condensed matter. Although the linewidths of many RIXS features are narrow, the experimental broadening can often hamper the…

Strongly Correlated Electrons · Physics 2012-02-13 J. Laverock , A. R. H. Preston , D. Newby , K. E. Smith , S. B. Dugdale

Deconvolving COMPTEL gamma-ray data into images presents a major methodological challenge. We developed a new algorithm called Multiresolution Regularized Expectation Maximization (MREM), which explicitly accounts for spatial correlations…

We report on an improvement to the implementation of the Maximum Entropy Method (MEM). It amounts to departing from the search space obtained through a singular value decomposition (SVD) of the Kernel. Based on the shape of the SVD basis…

Computational Physics · Physics 2015-03-20 Alexander Rothkopf

The standard implementation of the Maximum Entropy Method (MEM) follows Bryan and deploys a Singular Value Decomposition (SVD) to limit the dimensionality of the underlying solution space apriori. Here we present arguments based on the…

Computational Physics · Physics 2013-01-08 Alexander Rothkopf

We present and evaluate the application of the "Reconstructed Image from Simulations Ensemble" (RISE), a novel tomographic image reconstruction method, in infrared tomography. We demonstrate that established methods of photon emission…

The generalized maximum entropy method (GMEM) is a special modification of the standard maximum entropy method (MEM) which seeks solutions in the space of complex functions. In this work a reduced version of the GMEM intended for…

Astrophysics · Physics 2015-06-24 Anisa T. Bajkova

Mapping the relativistic jets emanating from AGN requires the use of a deconvolution algorithm to account for the effects of missing baseline spacings. The CLEAN algorithm is the most commonly used algorithm in VLBI imaging today and is…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 Colm P. Coughlan , Denise C. Gabuzda

We propose in this paper a novel, information-theoretic method, called MaxEnt, for efficient data acquisition for low-rank matrix recovery. This proposed method has important applications to a wide range of problems, including image…

Methodology · Statistics 2019-01-30 Simon Mak , Yao Xie
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