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In recent years, astronomical photometry has been revolutionised by space missions such as MOST, CoRoT and Kepler. However, despite this progress, high-quality spectroscopy is still required as well. Unfortunately, high-resolution spectra…

Solar and Stellar Astrophysics · Physics 2014-03-05 T. Van Reeth , A. Tkachenko , V. Tsymbal

Computational image reconstruction algorithms generally produce a single image without any measure of uncertainty or confidence. Regularized Maximum Likelihood (RML) and feed-forward deep learning approaches for inverse problems typically…

Machine Learning · Computer Science 2020-12-18 He Sun , Katherine L. Bouman

The quality of images of the Sun obtained from the ground are severely limited by the perturbing effect of the turbulent Earth's atmosphere. The post-facto correction of the images to compensate for the presence of the atmosphere require…

Solar and Stellar Astrophysics · Physics 2018-12-05 A. Asensio Ramos , J. de la Cruz Rodriguez , A. Pastor Yabar

Maximum-likelihood (ML) decoding can be used to obtain the optimal performance of error correction codes. However, the size of the search space and consequently the decoding complexity grows exponentially, making it impractical to be…

Information Theory · Computer Science 2022-05-25 Mohammad Rowshan , Jinhong Yuan

We characterize the improved angular and energy resolution of a new likelihood gamma-ray reconstruction for VERITAS. The algorithm uses the average photoelectrons stored in templates that are based on simulations of large numbers of showers…

Instrumentation and Methods for Astrophysics · Physics 2019-08-13 Jodi Christiansen

High resolution ultrasound image reconstruction from a reduced number of measurements is of great interest in ultrasound imaging, since it could enhance both the frame rate and image resolution. Compressive deconvolution, combining…

Computer Vision and Pattern Recognition · Computer Science 2015-12-18 Zhouye Chen , Adrian Basarab , Denis Kouamé

Speckle noise is an inherent disturbance in coherent imaging systems such as digital holography, synthetic aperture radar, optical coherence tomography, or ultrasound systems. These systems usually produce only single observation per view…

Image and Video Processing · Electrical Eng. & Systems 2022-05-19 Tsung-Ming Tai , Yun-Jie Jhang , Wen-Jyi Hwang , Chau-Jern Cheng

A long-standing issue in solar ground-based observations has been the contamination of data due to stray light, which is particularly relevant in inversions of spectropolarimetric data. We aim to build on a statistical method of correcting…

Solar and Stellar Astrophysics · Physics 2021-12-07 Sudharshan Saranathan , Michiel van Noort , Sami K. Solanki

We address the denoising of images contaminated with multiplicative noise, e.g. speckle noise. Classical ways to solve such problems are filtering, statistical (Bayesian) methods, variational methods, and methods that convert the…

Optimization and Control · Mathematics 2008-12-10 Sylvain Durand , Jalal Fadili , Mila Nikolova

Microscopy is one of the most essential imaging techniques in life sciences. High-quality images are required in order to solve (potentially life-saving) biomedical research problems. Many microscopy techniques do not achieve sufficient…

Computer Vision and Pattern Recognition · Computer Science 2018-10-24 Joris Roels , Jan Aelterman , Jonas De Vylder , Hiep Luong , Yvan Saeys , Wilfried Philips

We demonstrate high fidelity enhancement of planetary digital elevation models (DEMs) using optical images and deep learning with convolutional neural networks. Enhancement can be applied recursively to the limit of available optical data,…

Computer Vision and Pattern Recognition · Computer Science 2021-01-14 Casey Handmer

In this paper, we propose a Riemannian steepest descent method for solving a blind deconvolution problem. We prove that the proposed algorithm with an appropriate initialization will recover the exact solution with high probability when the…

Information Theory · Computer Science 2018-04-17 Wen Huang , Paul Hand

We report on the initial results obtained with an image convolution/deconvolution computer code that we developed and used to study the image formation capabilities of the solar gravitational lens (SGL). Although the SGL of a spherical Sun…

General Relativity and Quantum Cosmology · Physics 2021-06-15 Viktor T. Toth , Slava G. Turyshev

Removing the aberrations introduced by the Point Spread Function (PSF) is a fundamental aspect of astronomical image processing. The presence of noise in observed images makes deconvolution a nontrivial task that necessitates the use of…

Instrumentation and Methods for Astrophysics · Physics 2017-05-03 Samuel Farrens , Jean-Luc Starck , Fred Maurice Ngolè Mboula

We present a study of weak lensing shear measurements for simulated galaxy images at radio wavelengths. We construct a simulation pipeline into which we can input galaxy images of known ellipticity, and with which we then simulate…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Prina Patel , Filipe B. Abdalla , David J. Bacon , Barnaby Rowe , Oleg Smirnov , Rob J. Beswick

Despeckling is a crucial noise reduction task in improving the quality of synthetic aperture radar (SAR) images. Directly obtaining noise-free SAR images is a challenging task that has hindered the development of accurate despeckling…

Computer Vision and Pattern Recognition · Computer Science 2024-01-17 Shunya Kato , Masaki Saito , Katsuhiko Ishiguro , Sol Cummings

Aims. To investigate the performance of a deconvolution map-making algorithm for an experiment with a circular scanning strategy, specifically in this case for the analysis of Planck data, and to quantify the effects of making maps using…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 D. L. Harrison , F. van Leeuwen , M. A. J. Ashdown

In addition to the maximum likelihood approach, there are two other methods which are commonly used to reconstruct the true redshift distribution from photometric redshift datasets: one uses a deconvolution method, and the other a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Ravi K. Sheth , Graziano Rossi

Multi-look acquisition is a widely used strategy for reducing speckle noise in coherent imaging systems such as digital holography. By acquiring multiple measurements, speckle can be suppressed through averaging or joint reconstruction,…

Image and Video Processing · Electrical Eng. & Systems 2026-04-23 Xi Chen , Arian Maleki , Shirin Jalali

Gravitational lensing of the cosmic microwave background (CMB) polarization field has been recognized as a potentially valuable probe of the cosmological density field. We apply likelihood-based techniques to the problem of lensing of CMB…

Astrophysics · Physics 2011-06-21 Christopher M. Hirata , Uros Seljak
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