English
Related papers

Related papers: An improved method for polarimetric image restorat…

200 papers

Full Stokes filter-polarimeters are key instruments for investigating the rapid evolution of magnetic structures on the solar surface. To this end, the image quality is routinely improved using a-posteriori image reconstruction methods. We…

Solar and Stellar Astrophysics · Physics 2015-06-03 A. Asensio Ramos , M. J. Martinez Gonzalez , E. Khomenko , V. Martinez Pillet

Polarization imaging is a technique that creates a pixel map of the polarization state in a scene. Although invisible to the human eye, polarization can assist various sensing and computer vision tasks. Existing polarization cameras use…

Image and Video Processing · Electrical Eng. & Systems 2026-03-19 Noa Kraicer , Shay Elmalem , Erez Yosef , Hani Barhum , Raja Giryes

We present a two-channel deconvolution method that decomposes images into a parametric point-source channel and a pixelized extended-source channel. Based on the central idea of the deconvolution algorithm proposed by Magain, Courbin & Sohy…

Instrumentation and Methods for Astrophysics · Physics 2016-04-27 N. Cantale , F. Courbin , M. Tewes , P. Jablonka. , G. Meylan

We present a simple and effective approach for non-blind image deblurring, combining classical techniques and deep learning. In contrast to existing methods that deblur the image directly in the standard image space, we propose to perform…

Computer Vision and Pattern Recognition · Computer Science 2024-10-10 Jiangxin Dong , Stefan Roth , Bernt Schiele

Radio astronomy plays a crucial role in understanding the universe, particularly within the realm of non-thermal astrophysics. Images of celestial objects are derived from the signals (called visibility) measured by radio telescopes. Such…

Computer Vision and Pattern Recognition · Computer Science 2026-04-21 Kai Cheng , Ruoqi Wang , Qiong Luo

Application of deconvolution algorithms to astronomical images is often limited by variations in PSF structure over the domain of the images. One major difficulty is that Fourier methods can no longer be used for fast convolutions over the…

Astrophysics · Physics 2009-11-07 Tod R. Lauer

Within the context of upcoming full-sky lensing surveys, the edge-preserving non- linear algorithm Aski is presented. Using the framework of Maximum A Posteriori inversion, it aims at recovering the full-sky convergence map from surveys…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 C. Pichon , E. Thiebaut , S. Prunet , K. Benabed , S. Colombi , T. Sousbie , R. Teyssier

The new generation of deep photometric surveys requires unprecedentedly precise shape and photometry measurements of billions of galaxies to achieve their main science goals. At such depths, one major limiting factor is the blending of…

A deep neural networks based method is proposed to convert single polarization grayscale SAR image to fully polarimetric. It consists of two components: a feature extractor network to extract hierarchical multi-scale spatial features of…

Computer Vision and Pattern Recognition · Computer Science 2017-07-25 Qian Song , Feng Xu , Ya-Qiu Jin

In this work, an efficient numerical scheme is presented for seismic blind deconvolution in a multichannel scenario. The proposed method iterate with wo steps: first, wavelet estimation across all channels and second, refinement of the…

Computational Physics · Physics 2020-10-20 Naveed Iqbal , Entao Liu , James H. McClellan , Abdullatif A. Al-Shuhail

Beamforming is an essential step in the ultrasound image formation pipeline and has recently attracted growing interest. An important goal of beamforming is to increase the image spatial resolution, or in other words to narrow down the…

Image and Video Processing · Electrical Eng. & Systems 2022-09-01 Sobhan Goudarzi , Adrian Basarab , Hassan Rivaz

We present a blind multiframe image-deconvolution method based on robust statistics. The usual shortcomings of iterative optimization of the likelihood function are alleviated by minimizing the M-scale of the residuals, which achieves more…

Instrumentation and Methods for Astrophysics · Physics 2017-11-09 Matthias Lee , Tamas Budavari , Richard White , Charles Gulian

We present a comprehensive analysis of the performance of noise-reduction (``denoising'') algorithms to determine whether they provide advantages in source detection on extragalactic survey images. The methods under analysis are…

Instrumentation and Methods for Astrophysics · Physics 2020-11-04 V. Roscani , S. Tozza , M. Castellano , E. Merlin , D. Ottaviani , M. Falcone , A. Fontana

Context. Most popular algorithms in use to remove the effects of a telescope's point spread function (PSF) in radio astronomy are variants of the CLEAN algorithm. Most of these algorithms model the sky brightness using the delta-function…

Instrumentation and Methods for Astrophysics · Physics 2017-12-18 L. Zhang , S. Bhatnagar , U. Rau , M. Zhang

When inverting solar spectra, image degradation effects that are present in the data are usually approximated or not considered. We develop a data reduction method that takes these issues into account and minimizes the resulting errors. By…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 M. van Noort

CLEAN, the commonly employed imaging algorithm in radio interferometry, suffers from a number of shortcomings: in its basic version it does not have the concept of diffuse flux, and the common practice of convolving the CLEAN components…

Instrumentation and Methods for Astrophysics · Physics 2021-02-17 Philipp Arras , Hertzog L. Bester , Richard A. Perley , Reimar Leike , Oleg Smirnov , Rüdiger Westermann , Torsten A. Enßlin

The cosmological global (sky-averaged) 21-cm signal is a powerful tool to probe the evolution of the intergalactic medium (IGM) in high-redshift Universe ($z \leq 6$). One of the biggest observational challenges is to remove the foreground…

Instrumentation and Methods for Astrophysics · Physics 2018-11-14 Bang D. Nhan , Richard F. Bradley , Jack O. Burns

Tackling unsupervised source separation jointly with an additional inverse problem such as deconvolution is central for the analysis of multi-wavelength data. This becomes highly challenging when applied to large data sampled on the sphere…

Signal Processing · Electrical Eng. & Systems 2020-12-24 Rémi Carloni Gertosio , Jérôme Bobin

The process of wide-field synthesis imaging is explored, with the aim of understanding the implications of variable, polarised primary beams for forthcoming Epoch of Reionisation experiments. These experiments seek to detect weak signatures…

Instrumentation and Methods for Astrophysics · Physics 2012-06-05 Daniel A. Mitchell , Randall B. Wayth , Gianni Bernardi , Lincoln J. Greenhill , Stephen M. Ord

A Polarimetric Synthetic Aperture Radar (PolSAR) sensor is able to collect images in different polarization states, making it a rich source of information for target characterization. PolSAR images are inherently affected by speckle.…

Image and Video Processing · Electrical Eng. & Systems 2022-02-16 Adugna G. Mullissa , Claudio Persello , Johannes Reiche