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Incoherently illuminated or luminescent objects give rise to a low-contrast speckle-like pattern when observed through a thin diffusive medium, as such a medium effectively convolves their shape with a speckle-like point spread function…

Gaussianity of temperature fluctuations in the Cosmic Microwave Background(CMB) implies that the statistical properties of the temperature field can be completely characterized by its two point correlation function. The two point…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-25 Nidhi Joshi , Aditya Rotti , Tarun Souradeep

Diffusion maps is a manifold learning algorithm widely used for dimensionality reduction. Using a sample from a distribution, it approximates the eigenvalues and eigenfunctions of associated Laplace-Beltrami operators. Theoretical bounds on…

Statistics Theory · Mathematics 2021-04-09 Caroline L. Wormell , Sebastian Reich

A new method for estimating the angular power spectrum C_l from cosmic microwave background (CMB) maps is presented, which has the following desirable properties: (1) It is unbeatable in the sense that no other method can measure C_l with…

Astrophysics · Physics 2009-10-07 Max Tegmark

We present a semi-blind, spatially-variant deconvolution technique aimed at optical microscopy that combines a local estimation step of the point spread function (PSF) and deconvolution using a spatially variant, regularized Richardson-Lucy…

Computer Vision and Pattern Recognition · Computer Science 2019-05-21 Adrian Shajkofci , Michael Liebling

The Cosmological Microwave Background (CMB) is of premier importance for the cosmologists to study the birth of our universe. Unfortunately, most CMB experiments such as COBE, WMAP or Planck do not provide a direct measure of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 J. Bobin , J. -L. Starck , F. Sureau , S. Basak

An improved method for subtracting contaminants from Cosmic Microwave Background (CMB) sky maps is presented, and used to estimate how well future experiments will be able to recover the primordial CMB fluctuations. We find that the naive…

Astrophysics · Physics 2015-06-24 Max Tegmark , George Efstathiou

Multivariate global polynomial approximations - such as polynomial chaos or stochastic collocation methods - are now in widespread use for sensitivity analysis and uncertainty quantification. The pseudospectral variety of these methods uses…

Numerical Analysis · Mathematics 2013-04-09 Paul G. Constantine , Michael S. Eldred , Eric T. Phipps

In this article, we extend previous studies based on CMB spherical harmonic phases (SHP) to examine the validity of the hypothesis that the temperature field of the CMB is consistent with a Gaussian random field (GRF). The null hypothesis…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-11 Sarvesh Kumar Yadav , Rajib Saha

We present an algorithm to derive difference images for data taken with the JWST with matched point-spread functions (PSFs). It is based on the saccadic fast Fourier transform (SFFT) method but with revisions to accommodate the rotations…

Instrumentation and Methods for Astrophysics · Physics 2024-04-30 Lei Hu , Lifan Wang

In multi-photon microscopy (MPM), a recent in-vivo fluorescence microscopy system, the task of image restoration can be decomposed into two interlinked inverse problems: firstly, the characterization of the Point Spread Function (PSF) and…

Image and Video Processing · Electrical Eng. & Systems 2024-11-08 Julien Ajdenbaum , Emilie Chouzenoux , Claire Lefort , Ségolène Martin , Jean-Christophe Pesquet

Blind image deblurring is a long standing challenging problem in image processing and low-level vision. Recently, sophisticated priors such as dark channel prior, extreme channel prior, and local maximum gradient prior, have shown promising…

Image and Video Processing · Electrical Eng. & Systems 2020-10-30 Fei Wen , Rendong Ying , Yipeng Liu , Peilin Liu , Trieu-Kien Truong

Secondary contributions to the anisotropy of the Cosmic Microwave Background (CMB), such as the integrated Sachs-Wolfe (ISW) effect, the thermal Sunyaev-Zel'dovich effect (tSZ), and the effect of gravitational lensing, have distinctive…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-27 Dipak Munshi , Peter Coles , Alan Heavens

Precise knowledge of the point spread function (PSF) underpins many data analysis steps in astronomy, from photometry and astrometry to source de-blending and deconvolution. In adaptive optics (AO) observations, however, the PSF is highly…

Instrumentation and Methods for Astrophysics · Physics 2026-04-02 Arseniy Kuznetsov , Benoit Neichel , Sylvain Oberti , Thierry Fusco

This introductory guide aims to provide insight to new researchers in the field of cosmic microwave background (CMB) map analysis on best practices for several common procedures. We will discuss common map-modifying procedures such as…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-02 Raelyn Marguerite Sullivan , Lukas Tobias Hergt , Douglas Scott

The point-spread function (PSF) of an imaging system describes the response of the system to a point source. Accurately determining the PSF enables one to correct for the combined effects of focussing and scattering within the imaging…

Instrumentation and Methods for Astrophysics · Physics 2022-11-01 Stefan Johann Hofmeister , Michael Hahn , Daniel Wolf Savin

We have developed a novel method for co-adding multiple under-sampled images that combines the iteratively reweighted least squares and divide-and-conquer algorithms. Our approach not only allows for the anti-aliasing of the images but also…

Instrumentation and Methods for Astrophysics · Physics 2024-02-29 Lei Wang , Huanyuan Shan , Lin Nie , Dezi Liu , Zhaojun Yan , Guoliang Li , Cheng Cheng , Yushan Xie , Han Qu , Wenwen Zheng , Xi Kang

Separation of the B component of a cosmic microwave background (CMB) polarization map from the much larger E component is an essential step in CMB polarimetry. For a map with incomplete sky coverage, this separation is necessarily hampered…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-22 Emory F. Bunn

The problem of image blurring is one of the most studied topics in the field of image processing. Image blurring is caused by various factors such as hand or camera shake. To restore the blurred image, it is necessary to know information…

Computer Vision and Pattern Recognition · Computer Science 2023-10-03 M. Zarebnia , R. Parvaz

Symmetric nonnegative matrix factorization (SNMF) is equivalent to computing a symmetric nonnegative low rank approximation of a data similarity matrix. It inherits the good data interpretability of the well-known nonnegative matrix…

Numerical Analysis · Computer Science 2017-10-11 Qingjiang Shi , Haoran Sun , Songtao Lu , Mingyi Hong , Meisam Razaviyayn
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