English
Related papers

Related papers: An improved method for polarimetric image restorat…

200 papers

Space telescopes for solar hard X-ray imaging provide observations made of sampled Fourier components of the incoming photon flux. The aim of this study is to design an image reconstruction method relying on enhanced visibility…

Instrumentation and Methods for Astrophysics · Physics 2021-10-13 Emma Perracchione , Paolo Massa , Anna Maria Massone , Michele Piana

One of the major limitations of adaptive optics (AO) corrected image post-processing is the lack of knowledge on the system point spread function (PSF). The PSF is not always available as a direct imaging on isolated point like objects such…

Instrumentation and Methods for Astrophysics · Physics 2020-07-22 Romain Fétick , Laurent Mugnier , Thierry Fusco , Benoit Neichel

Images of the linear polarization of synchrotron radiation around Active Galactic Nuclei (AGN) identify their projected magnetic field lines and provide key data for understanding the physics of accretion and outflow from supermassive black…

Instrumentation and Methods for Astrophysics · Physics 2016-09-21 Andrew A. Chael , Michael D. Johnson , Ramesh Narayan , Sheperd S. Doeleman , John F. C. Wardle , Katherine L. Bouman

Purpose: To develop a general phase regularized image reconstruction method, with applications to partial Fourier imaging, water-fat imaging and flow imaging. Theory and Methods: The problem of enforcing phase constraints in reconstruction…

Computer Vision and Pattern Recognition · Computer Science 2017-09-26 Frank Ong , Joseph Cheng , Michael Lustig

We propose the application of multiresolution transforms, such as wavelets (WT) and curvelets (CT), to the reconstruction of images of extended objects that have been acquired with adaptive optics (AO) systems. Such multichannel approaches…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Roberto Baena Gallé , Jorge Núñez , Szymon Gladysz

Recently, novel quaternion-valued wavelets on the plane were constructed using an optimisation approach. These wavelets are compactly supported, smooth, orthonormal, non-separable and truly quaternionic. However, they have not been tested…

Computer Vision and Pattern Recognition · Computer Science 2024-01-12 Neil D. Dizon , Jeffrey A. Hogan

This paper introduces the Wide-band Asp-Clean (\texttt{WAsp}) algorithm, a novel scale-sensitive image reconstruction method tailored for wide-band imaging applications. This algorithm is particularly beneficial for thermal noise-limited…

Instrumentation and Methods for Astrophysics · Physics 2026-04-27 M. Hsieh , S. Bhatnagar , U. Rau

Images acquired with a telescope are blurred and corrupted by noise. The blurring is usually modeled by a convolution with the Point Spread Function and the noise by Additive Gaussian Noise. Recovering the observed image is an ill-posed…

Instrumentation and Methods for Astrophysics · Physics 2021-11-03 Fadi Nammour , Morgan A. Schmitz , Fred Maurice Ngolè Mboula , Jean-Luc Starck , Julien N. Girard

context: The combination of image restoration and a Fabry-P\'{e}rot interferometer (FPI) based instrument in solar observations results in specific calibration issues. FPIs generally show variations over the field-of-view, while in the…

Solar and Stellar Astrophysics · Physics 2015-05-20 R. S. Schnerr , J. de la Cruz Rodriguez , M. van Noort

Defect detection by ultrasonic method is limited by the pulse width. Resolution can be improved through a deconvolution process with a priori information of the pulse or by its estimation. In this paper a regularization of the Wiener filter…

Information Theory · Computer Science 2012-05-17 Roberto H. Herrera , Eduardo Moreno , Héctor Calas , Rubén Orozco

We revisit the impact of finite time responses of bolometric detectors used for deep observations of the cosmic microwave background (CMB). Until now, bolometer transfer functions have been accounted for through a two-step procedure by…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-21 A. Basyrov , N. O. Stutzer , J. G. S. Lunde , H. K. Eriksen , E. Gjerløw , D. J. Watts , I. K. Wehus

New generation of radio interferometers are envisaged to produce high quality, high dynamic range Stokes images of the observed sky from the corresponding under-sampled Fourier domain measurements. In practice, these measurements are…

Instrumentation and Methods for Astrophysics · Physics 2020-01-08 Jasleen Birdi , Audrey Repetti , Yves Wiaux

We describe a "spatio-spectral" deconvolution algorithm for wide-band imaging in radio interferometry. In contrast with the existing multi-frequency reconstruction algorithms, the proposed method does not rely on a model of the…

Instrumentation and Methods for Astrophysics · Physics 2016-03-01 André Ferrari , Jérémy Deguignet , Chiara Ferrari , David Mary , Antony Schutz , Oleg Smirnov

Although much research has been devoted to the problem of restoring Poissonian images, namely in the fields of medical and astronomical imaging, applying the state of the art regularizers (such as those based on wavelets or total variation)…

Optimization and Control · Mathematics 2009-05-01 Mario A. T. Figueiredo , Jose M. Bioucas-Dias

The subject of this paper is beam deconvolution in small angular scale CMB experiments. The beam effect is reversed using the Jacobi iterative method, which was designed to solved systems of algebraic linear equations. The beam is a non…

Astrophysics · Physics 2009-11-07 Carlo Burigana , Diego Saez

Images of near-field SAR contains spatial-variant sidelobes and clutter, subduing the image quality. Current image restoration methods are only suitable for small observation angle, due to their assumption of 2D spatial-invariant…

Signal Processing · Electrical Eng. & Systems 2022-10-06 Wensi Zhang , Xiaoling Zhang , Xu Zhan , Yuetonghui Xu , Jun Shi , Shunjun Wei

In recent years, there has been a proliferation of wide-field sky surveys to search for a variety of transient objects. Using relatively short focal lengths, the optics of these systems produce undersampled stellar images often marred by a…

Astrophysics · Physics 2009-11-13 Fang Yuan , Carl W. Akerlof

A division-of-focal-plane (DoFP) polarimeter enables us to acquire images with multiple polarization orientations in one shot and thus it is valuable for many applications using polarimetric information. The image processing pipeline for a…

Image and Video Processing · Electrical Eng. & Systems 2025-09-15 Muhamad Daniel Ariff Bin Abdul Rahman , Yusuke Monno , Masayuki Tanaka , Masatoshi Okutomi

The approaches for analyzing the polarimetric scattering matrix of polarimetric synthetic aperture radar (PolSAR) data have always been the focus of PolSAR image classification. Generally, the polarization coherent matrix and the covariance…

Computer Vision and Pattern Recognition · Computer Science 2019-04-26 Xu Liu , Licheng Jiao , Xu Tang , Qigong Sun , Dan Zhang

Next generation radio telescopes will be much larger, more sensitive, have much larger observation bandwidth and will be capable of pointing multiple beams simultaneously. Obtaining the sensitivity, resolution and dynamic range supported by…

Instrumentation and Methods for Astrophysics · Physics 2010-09-03 Ronny Levanda , Amir Leshem