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Optimal extraction is a key step in processing the raw images of spectra as registered by two-dimensional detector arrays to a one-dimensional format. Previously reported algorithms reconstruct models for a mean one-dimensional spatial…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 M. Zechmeister , G. Anglada-Escudé , A. Reiners

Precise knowledge of X-ray diffraction profile shape is crucial in the investigation of the properties of matter in crystals powder. Line-broadening analysis is a pre-processing step in most of the full powder pattern fitting softwares.…

Spectral Theory · Mathematics 2007-05-23 M. Ladisa , A. Lamura , T. Laudadio , G. Nico

We describe a scheme to extract linearly supporting (LSU) features from stellar spectra to automatically estimate the atmospheric parameters $T_{eff}$, log$~g$, and [Fe/H]. "Linearly supporting" means that the atmospheric parameters can be…

Solar and Stellar Astrophysics · Physics 2019-03-20 Xiangru Li , Yu Lu , Georges Comte , Ali Luo , Yongheng Zhao , Yongjun Wang

Two iterative techniques are described for decomposing a long-slit spectrum into the individual spectra of the point sources along the slit and the spectrum of the underlying background. One technique imposes the strong constraint that the…

Astrophysics · Physics 2009-11-07 L. B. Lucy , J. R. Walsh

This paper presents a novel Bayesian strategy for the estimation of smooth signals corrupted by Gaussian noise. The method assumes a smooth evolution of a succession of continuous signals that can have a numerical or an analytical…

Applications · Statistics 2016-02-12 Abderrahim Halimi , Gerald S. Buller , Steve McLaughlin , Paul Honeine

We present a simple and effective method to eliminate system aberrations and speckle noise in quantitative phase imaging. Using spiral integration, complete information about system aberration is calculated from three laterally shifted…

Biological Physics · Physics 2018-02-14 Inhyeok Choi , Kyeoreh Lee , YongKeun Park

Purpose: The set of linear attenuation coefficients that belong to materials in the human body is commonly assumed to be spanned by two basis functions in the range of clinical x-ray energies, even though there is evidence that the…

Medical Physics · Physics 2022-08-11 Fredrik Grönberg , Mats Persson , Hans Bornefalk

Spectral imaging is a method in medical x-ray imaging to extract information about the object constituents by the material-specific energy dependence of x-ray attenuation. Contrast-enhanced spectral imaging has been thoroughly investigated,…

Medical Physics · Physics 2021-01-26 Erik Fredenberg , Magnus Aslund , Bjorn Cederstrom , Mats Lundqvist , Mats Danielsson

An experimental search for variation in the fundamental coupling constants is strongly motivated by modern high-energy physics theories. Comparison of quasar absorption line spectra with laboratory spectra provides a sensitive probe for…

We consider the absorption of probe photons by electrons in the presence of an intense, pulsed, background field. Our analysis reveals an interplay between regularisation and gauge invariance which distinguishes absorption from its…

High Energy Physics - Phenomenology · Physics 2019-10-09 Anton Ilderton , Ben King , Alexander John Macleod

We recently presented a new "artificial intelligence" method for the analysis of high-resolution absorption spectra (Bainbridge and Webb, Mon. Not. R. Astron. Soc. 2017, 468,1639-1670). This new method unifies three established numerical…

Instrumentation and Methods for Astrophysics · Physics 2017-05-01 Matthew B. Bainbridge , John K. Webb

The decomposition of sounds into sines, transients, and noise is a long-standing research problem in audio processing. The current solutions for this three-way separation detect either horizontal and vertical structures or anisotropy and…

Audio and Speech Processing · Electrical Eng. & Systems 2022-12-01 Leonardo Fierro , Vesa Välimäki

Precise extraction of sinusoidal vibration parameters is essential for the dynamic calibration of vibration sensors, such as accelerometers. However, several standard methods have not yet been optimized for large background noise. In this…

Signal Processing · Electrical Eng. & Systems 2022-06-08 Tomofumi Shimoda , Wataru Kokuyama , Hideaki Nozato

Image foreground extraction is a classical problem in image processing and vision, with a large range of applications. In this dissertation, we focus on the extraction of text and graphics in mixed-content images, and design novel…

Computer Vision and Pattern Recognition · Computer Science 2018-04-10 Shervin Minaee

High-quality astronomical images delivered by modern ground-based and space observatories demand adequate, reliable software for their analysis and accurate extraction of sources, filaments, and other structures, containing massive amounts…

Instrumentation and Methods for Astrophysics · Physics 2021-05-26 A. Men'shchikov

The issue concerning the significant decline in the stability of feature extraction for images subjected to large-angle affine transformations, where the angle exceeds 50 degrees, still awaits a satisfactory solution. Even ASIFT, which is…

Computer Vision and Pattern Recognition · Computer Science 2025-03-06 Tao Wang , Yinghui Wang , Yanxing Liang , Liangyi Huang , Jinlong Yang , Wei Li , Xiaojuan Ning

Estimation of the covariance structure of spatial processes is of fundamental importance in spatial statistics. In the literature, several non-parametric and semi-parametric methods have been developed to estimate the covariance structure…

Methodology · Statistics 2016-11-06 Shu Yang , Zhengyuan Zhu

The fitting of spectral lines is a common step in the analysis of line observations and simulations. However, the observational noise, the presence of multiple velocity components, and potentially large data sets make it a non-trivial task.…

Astrophysics of Galaxies · Physics 2024-03-08 Mika Juvela , Devika Tharakkal

This paper presents a robust regression approach for image binarization under significant background variations and observation noises. The work is motivated by the need of identifying foreground regions in noisy microscopic image or…

Computer Vision and Pattern Recognition · Computer Science 2018-07-18 Garret Vo , Chiwoo Park

X-ray spectroscopy is a powerful technique for the analysis of the energy distribution of X-rays from astrophysical sources. It allows for the study of the properties, composition, and physical processes taking place at the site of…

High Energy Astrophysical Phenomena · Physics 2023-09-22 L. Ducci , C. Malacaria