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Lensless imaging offers a lightweight, compact alternative to traditional lens-based systems, ideal for exploration in space-constrained environments. However, the absence of a focusing lens and limited lighting in such environments often…

Image and Video Processing · Electrical Eng. & Systems 2025-01-14 Ziyang Liu , Tianjiao Zeng , Xu Zhan , Xiaoling Zhang , Edmund Y. Lam

We derive an estimator of weak gravitational lensing shear from background galaxy images that avoids noise-induced biases through a rigorous Bayesian treatment of the measurement. The derived shear estimator disposes with the assignment of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Gary M. Bernstein , Robert Armstrong

Generalizable neural surface reconstruction has become a compelling technique to reconstruct from few images without per-scene optimization, where dense 3D feature volume has proven effective as a global representation of scenes. However,…

Computer Vision and Pattern Recognition · Computer Science 2025-07-09 Aoxiang Fan , Corentin Dumery , Nicolas Talabot , Hieu Le , Pascal Fua

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

Metacalibration is a recently introduced method to accurately measure weak gravitational lensing shear using only the available imaging data, without need for prior information about galaxy properties or calibration from simulations. The…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-31 Erin S. Sheldon , Eric M. Huff

We explore the reconstruction of the gravitational lensing field of the cosmic microwave background in real space showing that very little statistical information is lost when estimators of short range on the celestial sphere are used in…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Martin Bucher , Carla Sofia Carvalho , Kavilan Moodley , Mathieu Remazeilles

We present a method to model optical images of galaxies using Expectation Maximization Principal Components Analysis (EMPCA). The method relies on the data alone and does not assume any pre-established model or fitting formula. It preserves…

Astrophysics of Galaxies · Physics 2017-08-16 Matteo Maturi

We introduce a continuous global optimization method to the field of surface reconstruction from discrete noisy cloud of points with weak information on orientation. The proposed method uses an energy functional combining flux-based…

Graphics · Computer Science 2017-08-01 Rongjiang Pan , Vaclav Skala

We present a new method for estimating galaxy cluster masses using weak-lensing magnification. The effect of weak-lensing magnification introduces a correlation between the position of foreground galaxy clusters and the density of…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-20 C. Murray , C. Combet , C. Payerne , M. Ricci

Weak lensing alters galaxy sizes and fluxes, influencing the clustering patterns of galaxies through cosmic magnification. This effect enables the reconstruction of weak lensing convergence $\hat{\kappa}$ maps for DES and DECaLS by linearly…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-23 Jian Qin , Pengjie Zhang , Zhu Chen , Liping Fu , Yu Yu , Haojie Xu , Ji Yao , Yuan Shi , Huanyuan Shan

Weak gravitational lensing analyses are fundamentally limited by the intrinsic, non-Gaussian distribution of galaxy shapes. We explore alternative statistics for samples of ellipticity measurements that are unbiased, efficient, and robust.…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-31 Merijn Smit , Konrad Kuijken

We study the limits of accuracy for weak lensing maps of dark matter using diffuse 21-cm radiation from the pre-reionization epoch using simulations. We improve on previous "optimal" quadratic lensing estimators by using shear and…

Astrophysics · Physics 2009-11-13 Tingting Lu , Ue-Li Pen

Point cloud obtained from 3D scanning is often sparse, noisy, and irregular. To cope with these issues, recent studies have been separately conducted to densify, denoise, and complete inaccurate point cloud. In this paper, we advocate that…

Computer Vision and Pattern Recognition · Computer Science 2022-03-16 Jaesung Choe , Byeongin Joung , Francois Rameau , Jaesik Park , In So Kweon

We apply an iterative reconstruction method to galaxy mocks in redshift space obtained from $N$-body simulations. Comparing the two-point correlation functions for the reconstructed density field, we find that although the performance is…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-26 Ryuichiro Hada , Daniel J. Eisenstein

We demonstrate that the maximum-entropy method for gravitational lens reconstruction presented in Bridle et al. (1998) may be applied even when only shear \emph{or} magnification information is present. We also demonstrate that the method…

Astrophysics · Physics 2007-05-23 S. L. Bridle , M. P. Hobson , Richard Saunders , A. N. Lasenby

Many applications and algorithms in the field of gravitational lensing make use of meshes with a finite number of nodes to analyze and manipulate data. Specific examples in lensing are astronomical CCD images in general, the reconstruction…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 Julian Merten

With the advent of next-generation surveys and the expectation of discovering huge numbers of strong gravitational lens systems, much effort is being invested into developing automated procedures for handling the data. The several orders of…

Astrophysics of Galaxies · Physics 2021-02-17 Jacob Maresca , Simon Dye , Nan Li

Observations of galaxy clustering are made in redshift space, which results in distortions to the underlying isotropic distribution of galaxies. These redshift-space distortions (RSD) not only degrade important features of the matter…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-29 Yuchan Wang , Baojiu Li , Marius Cautun

In this paper, we present a modular approach for reconstructing lensless measurements. It consists of three components: a newly-proposed pre-processor, a physics-based camera inverter to undo the multiplexing of lensless imaging, and a…

Image and Video Processing · Electrical Eng. & Systems 2024-09-26 Yohann Perron , Eric Bezzam , Martin Vetterli

Context: Weak gravitational lensing is a key cosmological probe for current and future large-scale surveys. While power spectra are commonly used for analyses, they fail to capture non-Gaussian information from nonlinear structure…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-17 Vilasini Tinnaneri Sreekanth , Jean-Luc Starck , Sandrine Codis
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