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We present GLIMPSE - Gravitational Lensing Inversion and MaPping with Sparse Estimators - a new algorithm to generate density reconstructions in three dimensions from photometric weak lensing measurements. This is an extension of earlier…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Adrienne Leonard , François Lanusse , Jean-Luc Starck

Modeling strong gravitational lenses in order to quantify the distortions in the images of background sources and to reconstruct the mass density in the foreground lenses has traditionally been a difficult computational challenge. As the…

Instrumentation and Methods for Astrophysics · Physics 2022-07-05 Alexandre Adam , Laurence Perreault-Levasseur , Yashar Hezaveh

The availability of affordable and portable depth sensors has made scanning objects and people simpler than ever. However, dealing with occlusions and missing parts is still a significant challenge. The problem of reconstructing a (possibly…

Computer Vision and Pattern Recognition · Computer Science 2018-04-05 Or Litany , Alex Bronstein , Michael Bronstein , Ameesh Makadia

This tutorial explains how to use piecewise cubic B\'ezier curves to draw arbitrarily oriented ellipses and elliptical arcs. The geometric principles discussed here result in strikingly simple interfaces for graphics functions that can draw…

Graphics · Computer Science 2024-08-12 Jerry R. Van Aken

The task of approximating points with circular arcs is performed in many applications, such as polyline compression, noise filtering, and feature recognition. However, the development of algorithms that perform a significant amount of…

Computational Geometry · Computer Science 2018-10-12 Alexander Gribov

Fitting concentric geometric objects to digitized data is an important problem in many areas such as iris detection, autonomous navigation, and industrial robotics operations. There are two common approaches to fitting geometric shapes to…

Computer Vision and Pattern Recognition · Computer Science 2021-03-10 Ali A. Al-Sharadqah , Lorenzo Rull

The number of gravitational arcs systems detected is increasing quickly and should even increase at a faster rate in the near future. This wealth of new gravitational arcs requires the development of a purely automated method to reconstruct…

Instrumentation and Methods for Astrophysics · Physics 2025-02-03 Christophe Alard

We describe the simulation data produced by a pilot programme to compute mock weak gravitational lensing maps for a range of currently popular cosmological models by ray tracing through high-resolution N-body simulations. The programme…

Astrophysics · Physics 2008-11-26 Martin White , Chris Vale

The existence of an arc statistics problem was at the center of a strong debate in the last fifteen years. With the aim to clarify if the optical depth for giant gravitational arcs by galaxy clusters in the so called concordance model is…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 M. Meneghetti , M. Bartelmann , H. Dahle , M Limousin

Image classifiers for domain-specific tasks like Synthetic Aperture Radar Automatic Target Recognition (SAR ATR) and chest X-ray classification often rely on convolutional neural networks (CNNs). These networks, while powerful, experience…

Computer Vision and Pattern Recognition · Computer Science 2024-06-28 Jacob Fein-Ashley , Sachini Wickramasinghe , Bingyi Zhang , Rajgopal Kannan , Viktor Prasanna

We consider a machine learning algorithm to detect and identify strong gravitational lenses on sky images. First, we simulate different artificial but very close to reality images of galaxies, stars and strong lenses, using six different…

Instrumentation and Methods for Astrophysics · Physics 2021-04-06 H. G. Khachatryan

Gravitational lensing refers to the deflection of light by the gravity of celestial bodies, often predominantly composed of dark matter. Seen through a gravitational lens, the images of distant galaxies appear distorted. In this paper we…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-22 Hans Georg Schaatun , Ben David Normann , Einar Leite Austnes , Simon Ingebrigtsen , Sondre Westbø Remøy , Simon Nedreberg Runde

Our work aims to reconstruct hand-held objects given a single RGB image. In contrast to prior works that typically assume known 3D templates and reduce the problem to 3D pose estimation, our work reconstructs generic hand-held object…

Computer Vision and Pattern Recognition · Computer Science 2022-04-15 Yufei Ye , Abhinav Gupta , Shubham Tulsiani

The statistics of gravitationally lensed arcs, which can be used for a variety of cosmological tests, are sensitive to the intrinsic shapes of the source galaxies. I present an analytic formalism that makes it simple to include elliptical…

Astrophysics · Physics 2009-11-06 Charles R. Keeton

In this brief communication a new method is outlined for modelling magnification patterns on an observer's plane using a first order approximation to the null geodesic path equations for a point mass lens. For each ray emitted from a…

Instrumentation and Methods for Astrophysics · Physics 2017-02-08 S. J. Walters , L. K. Forbes

We compare the statistical properties of giant gravitationally lensed arcs produced in matched simulated and observed cluster samples. The observed sample consists of 10 X-ray selected clusters at redshifts z ~ 0.2 imaged with HST by Smith…

We propose a new algorithm for real-time detection and tracking of elliptic patterns suitable for real-world robotics applications. The method fits ellipses to each contour in the image frame and rejects ellipses that do not yield a good…

Robotics · Computer Science 2021-12-09 Azarakhsh Keipour , Guilherme A. S. Pereira , Sebastian Scherer

Many robotic tasks involving some form of 3D visual perception greatly benefit from a complete knowledge of the working environment. However, robots often have to tackle unstructured environments and their onboard visual sensors can only…

Computer Vision and Pattern Recognition · Computer Science 2022-10-24 Andrea Rosasco , Stefano Berti , Fabrizio Bottarel , Michele Colledanchise , Lorenzo Natale

One of the most fascinating predictions of the theory of general relativity is the effect of gravitational lensing, the bending of light in close proximity to massive stellar objects. Recently, artificial optical materials have been…

Optics · Physics 2013-10-01 C. Sheng , H. Liu , Y. Wang , S. N. Zhu , D. A. Genov

Archetypal analysis represents a set of observations as convex combinations of pure patterns, or archetypes. The original geometric formulation of finding archetypes by approximating the convex hull of the observations assumes them to be…

Machine Learning · Statistics 2014-04-08 Sohan Seth , Manuel J. A. Eugster