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The coded aperture imaging technique is a useful method of X-ray imaging in observational astrophysics. However, the presence of imaging noise or so-called artifacts in a decoded image is a drawback of this method. We propose a new coded…

Instrumentation and Methods for Astrophysics · Physics 2020-08-03 Tomoaki Kasuga , Hirokazu Odaka , Kosuke Hatauchi , Satoshi Takashima , Tsubasa Tamba , Yuki Aizawa , Soichiro Hashiba , Aya Bamba , Yuanhui Zhou , Toru Tamagawa

Galactic all-sky maps at very disparate frequencies, like in the radio and $\gamma$-ray regime, show similar morphological structures. This mutual information reflects the imprint of the various physical components of the interstellar…

Three-dimensional phase contrast imaging of multiply-scattering samples in X-ray and electron microscopy is extremely challenging, due to small numerical apertures, the unavailability of wavefront shaping optics, and the highly nonlinear…

Computational Physics · Physics 2021-06-02 Philipp M Pelz , Hamish G Brown , Jim Ciston , Scott D Findlay , Yaqian Zhang , Mary Scott , Colin Ophus

We consider numerical solution of elliptic problems with heterogeneous diffusion coefficients containing thin highly conductive structures. Such problems arise e.g. in fractured porous media, reinforced materials, and electric circuits. The…

Numerical Analysis · Mathematics 2020-07-22 Fredrik Hellman , Axel Målqvist , Siyang Wang

In many astrophysical systems, smoothly-varying large-scale variations coexist with small-scale fluctuations. For example, a large-scale velocity or density gradient can exist in molecular clouds that exhibit small-scale turbulence. In…

Instrumentation and Methods for Astrophysics · Physics 2017-10-20 Jungyeon Cho

In many inverse problems, model parameters cannot be precisely determined from observational data. Bayesian inference provides a mechanism for capturing the resulting parameter uncertainty, but typically at a high computational cost. This…

Computation · Statistics 2019-03-28 Matthew Parno , Tarek Moselhy , Youssef Marzouk

This paper proposes a novel algorithm for the problem of structural image segmentation through an interactive model-based approach. Interaction is expressed in the model creation, which is done according to user traces drawn over a given…

Computer Vision and Pattern Recognition · Computer Science 2008-05-16 Alexandre Noma , Ana B. V. Graciano , Luis Augusto Consularo , Roberto M. Cesar-Jr , Isabelle Bloch

We present a progressive image decomposition method based on a novel non-linear filter named Sub-window Variance filter. Our method is specifically designed for image detail enhancement purpose; this application requires extraction of image…

Computer Vision and Pattern Recognition · Computer Science 2021-07-23 Kin-Ming Wong

Dictionary learning is a challenge topic in many image processing areas. The basic goal is to learn a sparse representation from an overcomplete basis set. Due to combining the advantages of generic multiscale representations with learning…

Computer Vision and Pattern Recognition · Computer Science 2017-04-17 Rui Chen , Huizhu Jia , Xiaodong Xie , Wen Gao

Performing a large number of spatial measurements enables high-resolution photoacoustic imaging without specific prior information. However, the acquisition of spatial measurements is time-consuming, costly, and technically challenging. By…

Numerical Analysis · Mathematics 2021-01-12 Gerhard Zangerl , Markus Haltmeier

Photometric surveys have provided incredible amounts of astronomical information in the form of images. However, astronomical images often contain artifacts that can critically hinder scientific analysis by misrepresenting intensities or…

Instrumentation and Methods for Astrophysics · Physics 2020-06-03 Suchetha Cooray , Tsutomu T. Takeuchi , Moe Yoda , Kazuo Sorai

Deconvolution of astronomical images is a key aspect of recovering the intrinsic properties of celestial objects, especially when considering ground-based observations. This paper explores the use of diffusion models (DMs) and the Diffusion…

Instrumentation and Methods for Astrophysics · Physics 2025-01-22 Alessio Spagnoletti , Alexandre Boucaud , Marc Huertas-Company , Wassim Kabalan , Biswajit Biswas

Resolving fine details of astronomical objects provides critical insights into their underlying physical processes. This drives in part the desire to construct ever-larger telescopes and interferometer arrays and to observe at shorter…

We have developed a method that maps large astronomical images onto a two-dimensional map and clusters them. A combination of various state-of-the-art machine learning (ML) algorithms is used to develop a fully unsupervised image quality…

Instrumentation and Methods for Astrophysics · Physics 2021-04-28 Hossen Teimoorinia , Sara Shishehchi , Ahnaf Tazwar , Ping Lin , Finn Archinuk , Stephen D. J. Gwyn , J. J. Kavelaars

Diffusion models are widely used in applications ranging from image generation to inverse problems. However, training diffusion models typically requires clean ground-truth images, which are unavailable in many applications. We introduce…

Image and Video Processing · Electrical Eng. & Systems 2025-05-20 Chicago Y. Park , Shirin Shoushtari , Hongyu An , Ulugbek S. Kamilov

A simple, yet general, formalism for the optimized linear combination of astrophysical images is constructed and demonstrated. The formalism allows the user to combine multiple undersampled images to provide oversampled output at high…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Barnaby Rowe , Christopher Hirata , Jason Rhodes

We developed a Python based framework for astronomical image processing and analysis. Astronomical image loading, normalizing, stacking, and filtering processes represent visible range images from grayscale. Besides, the blending process…

Instrumentation and Methods for Astrophysics · Physics 2024-10-10 Tanmoy Bhowmik , MD Fardin Islam , Kazi Nusrat Tasneem , Rantideb Roy , Rownok Shahariar

For an artist or a graphic designer, the spatial layout of a scene is a critical design choice. However, existing text-to-image diffusion models provide limited support for incorporating spatial information. This paper introduces Composite…

Computer Vision and Pattern Recognition · Computer Science 2023-07-27 Vikram Jamwal , Ramaneswaran S

The development of signal unmixing algorithms is essential for leveraging multimodal datasets acquired through a wide array of scientific imaging technologies, including hyperspectral or time-resolved acquisitions. In experimental physics,…

Image restoration aims to recover high-quality images from degraded observations. When the degradation process is known, the recovery problem can be formulated as an inverse problem, and in a Bayesian context, the goal is to sample a clean…

Image and Video Processing · Electrical Eng. & Systems 2025-10-13 Darshan Thaker , Abhishek Goyal , René Vidal