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Related papers: Digital Deblurring of CMB Maps II: Asymmetric Poin…

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Digital deblurring of images is an important problem that arises in multifrequency observations of the Cosmic Microwave Background (CMB) where, because of the width of the point spread functions (PSF), maps at different frequencies suffer a…

Astrophysics · Physics 2009-11-07 R. Vio , J. G. Nagy , L. Tenorio , P. Andreani , C. Baccigalupi , W. Wamsteker

We describe a fast and accurate method to perform the convolution of a sky map with a general asymmetric main beam along any given scanning strategy. The method is based on the decomposition of the beam as a sum of circular functions, here…

Astrophysics · Physics 2009-11-10 M. Tristram , J. -C. Hamilton , J. F. Macias-Perez , C. Renault

Modeling the Point Spread Function (PSF) of wide-field surveys is vital for many astrophysical applications and cosmological probes including weak gravitational lensing. The PSF smears the image of any recorded object and therefore needs to…

Instrumentation and Methods for Astrophysics · Physics 2018-07-26 Jörg Herbel , Tomasz Kacprzak , Adam Amara , Alexandre Refregier , Aurelien Lucchi

We propose fast, exact and efficient algorithms for the convolution of two arbitrary functions on the sphere which speed up computations by a factor \order{\sqrt{N}} compared to present methods where $N$ is the number of pixels. No…

Astrophysics · Physics 2009-10-31 Benjamin D. Wandelt , Krzysztof M. Gorski

We describe a new map-making code for cosmic microwave background (CMB) observations. It implements fast algorithms for convolution and transpose convolution of two functions on the sphere (Wandelt & G\'{o}rski 2001). Our code can account…

Astrophysics · Physics 2009-11-10 Charmaine Armitage , Benjamin D. Wandelt

Deblurring is a fundamental inverse problem in bioimaging. It requires modelling the point spread function (PSF), which captures the optical distortions entailed by the image formation process. The PSF limits the spatial resolution…

Image and Video Processing · Electrical Eng. & Systems 2019-03-04 Denis K. Samuylov , Prateek Purwar , Gábor Székely , Grégory Paul

This Point spread function (PSF) plays a crucial role in many computational imaging applications, such as shape from focus/defocus, depth estimation, and fluorescence microscopy. However, the mathematical model of the defocus process is…

Computer Vision and Pattern Recognition · Computer Science 2022-09-20 Renzhi He , Yan Zhuang , Boya Fu , Fei Liu

A new method for removing point radio sources and other non-Gaussian noise is proposed as a means of improving the accuracy of estimates of the angular power spectrum of the cosmic microwave background (CMB). The main idea of the method is…

Astrophysics · Physics 2009-11-13 Anisa T. Bajkova

This paper demonstrates a practical method that can correct spatial varying blur from a set of images of the same object. The algorithm jointly estimates the object and local point spread functions~(PSF). The method prioritizes sections…

Image and Video Processing · Electrical Eng. & Systems 2020-11-04 Wouter van de Ketterij , Oleg Soloviev , Michel Verhaegen

In this work we deal with the problem of simultaneous multifrequency detection of extragalactic point sources in maps of the Cosmic Microwave Background. We apply a linear filtering technique that uses spatial information and the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 L. F. Lanz , D. Herranz , J. L. Sanz , J. González-Nuevo , M. López-Caniego

A new method is presented for determining the Point Spread Function (PSF) of images that lack bright and isolated stars. It is based on the same principles as the MCS (Magain, Courbin, Sohy, 1998) image deconvolution algorithm. It uses the…

Astrophysics · Physics 2009-11-11 P. Magain , F. Courbin , M. Gillon , S. Sohy , G. Letawe , V. Chantry , Y. Letawe

Images from adaptive optics systems are generally affected by significant distortions of the point spread function (PSF) across the field of view, depending on the position of natural and artificial guide stars. Image reduction techniques…

Instrumentation and Methods for Astrophysics · Physics 2015-06-24 Andrea La Camera , Laura Schreiber , Emiliano Diolaiti , Patrizia Boccacci , Mario Bertero , Michele Bellazzini , Paolo Ciliegi

Deconvolution is the most commonly used image processing method to remove the blur caused by the point-spread-function (PSF) in optical imaging systems. While this method has been successful in deblurring, it suffers from several…

Image and Video Processing · Electrical Eng. & Systems 2019-10-10 Huangxuan Zhao , Ziwen Ke , Ningbo Chen , Ke Li , Lidai Wang , Xiaojing Gong , Wei Zheng , Liang Song , Zhicheng Liu , Dong Liang , Chengbo Liu

Scanning Kelvin probe microscopy (SKPM) is a powerful technique for investigating the electrostatic properties of material surfaces, enabling the imaging of variations in work function, topology, surface charge density, or combinations…

Applied Physics · Physics 2024-07-26 Isaac C. D. Lenton , Felix Pertl , Lubuna Shafeek , Scott R. Waitukaitis

Simulated maps of the microwave background (CMB) radiation are generally created using one of two methods: all-sky simulations use the spherical harmonic transform, while maps covering small areas approximate the sky as flat, allowing the…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-22 Mariona Giner Mascarell , Emory F. Bunn

We introduce a novel framework for upsampled Point Spread Function (PSF) modeling using pixel-level Bayesian inference. Accurate PSF characterization is critical for precision measurements in many fields including: weak lensing, astrometry,…

Instrumentation and Methods for Astrophysics · Physics 2025-11-26 Connor Stone , Ronan Legin , Alexandre Adam , Nikolay Malkin , Gabriel Missael Barco , Laurence Perreaul-Levasseur , Yashar Hezaveh

Simulated images are essential in algorithm development and instrument testing for optical telescopes. During real observations, images obtained by optical telescopes are affected by spatially variable point spread functions (PSFs), a…

Instrumentation and Methods for Astrophysics · Physics 2025-02-17 Zeyu Bai , Peng Jia , Jiameng Lv , Xiang Zhang , Wennan Xiang , Lin Nie

A method for spatial deconvolution of spectra is presented. It follows the same fundamental principles as the ``MCS image deconvolution algorithm'' (Magain, Courbin, Sohy, 1998) and uses information contained in the spectrum of a reference…

Astrophysics · Physics 2009-10-31 F. Courbin , P. Magain , M. Kirkove , S. Sohy

Optical microscopy is an essential tool in biology and medicine. Imaging thin, yet non-flat objects in a single shot (without relying on more sophisticated sectioning setups) remains challenging as the shallow depth of field that comes with…

Image and Video Processing · Electrical Eng. & Systems 2020-10-14 Adrian Shajkofci , Michael Liebling

X-ray cone-beam computed tomography (CT) has the notable features such as high efficiency and precision, and is widely used in the fields of medical imaging and industrial non-destructive testing, but the inherent imaging degradation…

Optics · Physics 2015-06-19 Hua Zhang , Kuidong Huang , Yikai Shi , Zhe Xu
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