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Richardson-Lucy deconvolution is widely used to restore images from degradation caused by the broadening effects of a point spread function and corruption by photon shot noise, in order to recover an underlying object. In practice, this is…

Computer Vision and Pattern Recognition · Computer Science 2024-11-05 Zachary H. Hendrix , Peter T. Brown , Tim Flanagan , Douglas P. Shepherd , Ayush Saurabh , Steve Pressé

Very recently a new inversion method has been developped to analyze the intergalactic medium seen in absorption in quasar spectra (the so-called Lyman-alpha forest). This method is applied to recover the temperature of the gas and the…

Multi-view mesh reconstruction remains a core challenge in computer graphics and vision, especially for recovering high-frequency geometry from sparse observations. Recent methods such as 3D Gaussian Splatting (3DGS) and Neural Radiance…

Computer Vision and Pattern Recognition · Computer Science 2026-05-11 Nandhana Sunil , Abhirami R Iyer , Avirup Mandal

Speed-of-sound is a biomechanical property for quantitative tissue differentiation, with great potential as a new ultrasound-based image modality. A conventional ultrasound array transducer can be used together with an acoustic mirror, or…

Computer Vision and Pattern Recognition · Computer Science 2018-07-20 Valery Vishnevskiy , Sergio J Sanabria , Orcun Goksel

This work presents a new physically-motivated supervised machine learning method, Hydro-BAM, to reproduce the three-dimensional Lyman-$\alpha$ forest field in real and in redshift space learning from a reference hydrodynamic simulation,…

Large-scale 3D reconstruction is critical in the field of robotics, and the potential of 3D Gaussian Splatting (3DGS) for achieving accurate object-level reconstruction has been demonstrated. However, ensuring geometric accuracy in outdoor…

Robotics · Computer Science 2024-09-20 Changjian Jiang , Ruilan Gao , Kele Shao , Yue Wang , Rong Xiong , Yu Zhang

Solving complex optimization problems in engineering and the physical sciences requires repetitive computation of multi-dimensional function derivatives. Commonly, this requires computationally-demanding numerical differentiation such as…

Numerical Analysis · Mathematics 2021-05-12 Danny Smyl , Tyler N. Tallman , Dong Liu , Andreas Hauptmann

The fluctuating Gunn-Peterson approximation (FGPA) is a commonly-used method to generate mock Lyman-$\alpha$ (Ly$\alpha$) forest absorption skewers at Cosmic Noon ($z\gtrsim 2$) from the matter-density field of $N$-body simulations without…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-26 Robin Kooistra , Khee-Gan Lee , Benjamin Horowitz

The inference of astrophysical and cosmological properties from the Lyman-$\alpha$ forest conventionally relies on summary statistics of the transmission field that carry useful but limited information. We present a deep learning framework…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-11 Parth Nayak , Michael Walther , Daniel Gruen , Sreyas Adiraju

It is well-known that the noise associated with the collection of an astronomical image by a CCD camera is, in large part, Poissonian. One would expect, therefore, that computational approaches that incorporate this a priori information…

Astrophysics · Physics 2009-11-10 R. Vio , J. Bardsley , W. Wamsteker

In this work, we consider the inverse problem of reconstructing the internal structure of an object from limited x-ray projections. We use a Gaussian process prior to model the target function and estimate its (hyper)parameters from…

Computer Vision and Pattern Recognition · Computer Science 2019-07-04 Zenith Purisha , Carl Jidling , Niklas Wahlström , Simo Särkkä , Thomas B. Schön

In this work we expand upon the Tomographic Absorption Reconstruction and Density Inference Scheme (TARDIS) in order to include multiple tracers while reconstructing matter density fields at Cosmic Noon (z ~ 2-3). In particular, we jointly…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-26 Benjamin Horowitz , Benjamin Zhang , Khee-Gan Lee , Robin Kooistra

We address the problem of inferring the three-dimensional matter distribution from a sparse set of one-dimensional quasar absorption spectra of the Lyman-$\alpha$ forest. Using a Bayesian forward modelling approach, we focus on extending…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Natalia Porqueres , Oliver Hahn , Jens Jasche , Guilhem Lavaux

For numerous parameter and state estimation problems, assimilating new data as they become available can help produce accurate and fast inference of unknown quantities. While most existing algorithms for solving those kind of ill-posed…

Numerical Analysis · Mathematics 2022-07-28 Neil K. Chada , Marco A. Iglesias , Shuai Lu , Frank Werner

Mathematical methods of step-by-step and combined shifts are proposed for experimental data processing to reconstruct the measuring system impulse response distorted by shift-invariant blur. Proposed methods base on direct non-blind…

Signal Processing · Electrical Eng. & Systems 2019-01-24 Andrey V. Novikov-Borodin

Full-physics cosmological simulations are powerful tools for studying the formation and evolution of structure in the universe but require extreme computational resources. Here, we train a convolutional neural network to use a cheaper…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-04 Peter Harrington , Mustafa Mustafa , Max Dornfest , Benjamin Horowitz , Zarija Lukić

We introduce a novel optimization algorithm for image recovery under learned sparse and low-rank constraints, which we parameterize as weighted extensions of the $\ell_p^p$-vector and $\mathcal S_p^p$ Schatten-matrix quasi-norms for…

Computer Vision and Pattern Recognition · Computer Science 2023-04-21 Stamatios Lefkimmiatis , Iaroslav Koshelev

The Richardson-Lucy unfolding approach is simple and excellently performing. It efficiently suppresses artificial high frequency contributions and permits to introduce known features of the true distribution. An algorithm to fix the number…

Data Analysis, Statistics and Probability · Physics 2015-06-11 Guenter Zech

We present a statistical framework to benchmark the performance of reconstruction algorithms for linear inverse problems, in particular, neural-network-based methods that require large quantities of training data. We generate synthetic…

Signal Processing · Electrical Eng. & Systems 2023-07-05 Pakshal Bohra , Pol del Aguila Pla , Jean-François Giovannelli , Michael Unser

Non-linear least squares solvers are used across a broad range of offline and real-time model fitting problems. Most improvements of the basic Gauss-Newton algorithm tackle convergence guarantees or leverage the sparsity of the underlying…

Computer Vision and Pattern Recognition · Computer Science 2020-10-22 Huu Le , Christopher Zach , Edward Rosten , Oliver J. Woodford