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Related papers: Modelling, Measuring and Compensating Color Weak V…

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Intrinsic alignments of galaxies are recognised as one of the most important systematic in weak lensing surveys on small angular scales. In this paper we investigate ellipticity correlation functions that are measured separately on…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-04 Tim M. Tugendhat , Robert Reischke , Bjoern Malte Schaefer

To what extent are two images picturing the same 3D surfaces? Even when this is a known scene, the answer typically requires an expensive search across scale space, with matching and geometric verification of large sets of local features.…

Computer Vision and Pattern Recognition · Computer Science 2020-08-14 Anita Rau , Guillermo Garcia-Hernando , Danail Stoyanov , Gabriel J. Brostow , Daniyar Turmukhambetov

Weak gravitational lensing by the intervening large-scale structure of the Universe induces high-order correlations in the cosmic microwave background (CMB) temperature and polarization fields. We construct minimum variance estimators of…

Astrophysics · Physics 2008-11-26 Wayne Hu , Takemi Okamoto

We present a novel, easy-to-use method based on the photon-mapping technique to simulate photometric images of moving targets. Realistic images can be created in two passes: photon tracing and image rendering. The nature of light sources,…

Instrumentation and Methods for Astrophysics · Physics 2021-10-13 Junju Du , Shaoming Hu , Xu Chen , Hai Cao , Yuchen Jiang

When a luminous source is extended, its distortions by weak gravitational lensing are richer than a mere combination of magnification and shear. In a recent work, we proposed an elegant formalism based on complex analysis to describe and…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-29 Pierre Fleury , Julien Larena , Jean-Philippe Uzan

In this paper, we propose a color to grayscale image conversion algorithm (C2G) that aims to preserve the perceptual properties of the color image as much as possible. To this end, we propose measures for two perceptual properties based on…

Computer Vision and Pattern Recognition · Computer Science 2016-05-09 Shaodi You , Nick Barnes , Janine Walker

I explore the mathematical transformation that occurs in color coordinate space when physically mixing paints of two different colors. I tested 120 pairs of 16 paint colors and used a linear regression to find the most accurate combination…

Optics · Physics 2024-06-25 Alexander Messick

Adversarial perturbation of images, in which a source image is deliberately modified with the intent of causing a classifier to misclassify the image, provides important insight into the robustness of image classifiers. In this work we…

Computer Vision and Pattern Recognition · Computer Science 2021-03-24 Robert Bassett , Mitchell Graves , Patrick Reilly

This paper proposes an observer for generating depth maps of a scene from a sequence of measurements acquired by a two-plane light-field (plenoptic) camera. The observer is based on a gradient-descent methodology. The use of motion allows…

Optimization and Control · Mathematics 2018-09-24 Sean G. P. O'Brien , Jochen Trumpf , Viorela Ila , Robert Mahony

It is a mystery how the brain decodes color vision purely from the optic nerve signals it receives, with a core inferential challenge being how it disentangles internal perception with the correct color dimensionality from the unknown…

Neural and Evolutionary Computing · Computer Science 2025-03-04 Atsunobu Kotani , Ren Ng

This paper presents a blind detection and compensation technique for camera lens geometric distortions. The lens distortion introduces higher-order correlations in the frequency domain and in turn it can be detected using higher-order…

Computer Vision and Pattern Recognition · Computer Science 2007-05-23 Lili Ma , YangQuan Chen , Kevin L. Moore

Weak lensing (WL) promises to be a particularly sensitive probe of both the growth of large scale structure (LSS) as well as the fundamental relation between matter density perturbations and metric perturbations, thus providing a powerful…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-25 Geraint Pratten , Dipak Munshi , Patrick Valageas , Philippe Brax

The loss of contrast in double-slit electron-diffraction due to dephasing and decoherence processes is studied. It is shown that the spatial correlation function of diffraction patterns can be used to distinguish between dephasing and…

Quantum Physics · Physics 2018-04-18 Zilin Chen , Peter J. Beierle , Herman Batelaan

We present the theoretical and analytical bases of optimal techniques to measure weak gravitational shear from images of galaxies. We first characterize the geometric space of shears and ellipticity, then use this geometric interpretation…

Astrophysics · Physics 2009-11-06 G. M. Bernstein , M. Jarvis

Local and global illumination were recently defined in Riemannian manifolds to visualize classical Non-Euclidean spaces. This work focuses on Riemannian metric construction in $\mathbb{R}^3$ to explore special effects like warping, mirages,…

Graphics · Computer Science 2020-05-13 Tiago Novello , Vinícius da Silva , Luiz Velho

Weak gravitational lensing surveys measure the distortion of the image of distant sources due to the deflections of light rays by the fluctuations of the gravitational potential along the line of sight. Since they probe the non-linear…

Astrophysics · Physics 2009-11-13 Dipak Munshi , Patrick Valageas

Current perceptual similarity metrics operate at the level of pixels and patches. These metrics compare images in terms of their low-level colors and textures, but fail to capture mid-level similarities and differences in image layout,…

Computer Vision and Pattern Recognition · Computer Science 2026-05-27 Stephanie Fu , Netanel Tamir , Shobhita Sundaram , Lucy Chai , Richard Zhang , Tali Dekel , Phillip Isola

Weak lensing provides a direct measure of the distribution of mass in the universe, and is therefore a uniquely powerful probe of dark matter. Weak lensing can also be used to measure the twin phenomenon of dark energy, via its effect upon…

Astrophysics · Physics 2007-05-23 Richard Massey , Alexandre Refregier , Jason Rhodes

One of the most important combinatorial optimization problems is graph coloring. There are several variations of this problem involving additional constraints either on vertices or edges. They constitute models for real applications, such…

Data Structures and Algorithms · Computer Science 2016-06-17 Rosiane de Freitas , Bruno Dias , Nelson Maculan , Jayme Szwarcfiter

In the very near future, weak lensing surveys will map the projected density of the universe in an unbiased way over large regions of the sky. In order to interpret the results of studies it is helpful to develop an understanding of the…

Astrophysics · Physics 2008-11-26 Dipak Munshi , Peter Coles