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Related papers: Sparse Lens Inversion Technique (SLIT): lens and s…

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We introduce SynthLight, a diffusion model for portrait relighting. Our approach frames image relighting as a re-rendering problem, where pixels are transformed in response to changes in environmental lighting conditions. Using a…

Computer Vision and Pattern Recognition · Computer Science 2025-01-17 Sumit Chaturvedi , Mengwei Ren , Yannick Hold-Geoffroy , Jingyuan Liu , Julie Dorsey , Zhixin Shu

Optical flow is the pattern of apparent motion of objects in a scene. The computation of optical flow is a critical component in numerous computer vision tasks such as object detection, visual object tracking, and activity recognition.…

Signal Processing · Electrical Eng. & Systems 2024-01-15 Muhammad Wasim Nawaz , Abdesselam Bouzerdoum , Muhammad Mahboob Ur Rahman , Ghulam Abbas , Faizan Rashid

We address the problem of sparse recovery in an online setting, where random linear measurements of a sparse signal are revealed sequentially and the objective is to recover the underlying signal. We propose a reweighted least squares (RLS)…

Machine Learning · Computer Science 2017-06-30 Subhadip Mukherjee , Deepak R. , Huaijin Chen , Ashok Veeraraghavan , Chandra Sekhar Seelamantula

We propose a novel method for 3D object reconstruction from a sparse set of views captured from a 360-degree calibrated camera rig. We represent the object surface through a hybrid model that uses both an MLP-based neural representation and…

Computer Vision and Pattern Recognition · Computer Science 2024-03-29 Llukman Cerkezi , Paolo Favaro

We introduce a new algorithm designed for use with extended lensed images, specifically giant arcs lensed by galaxy clusters. These highly magnified images contain important information about both the mass distribution of the cluster and…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-25 Lana Eid , Charles Keeton

Extended source effects can be seen in gravitational lensing events when sources cross critical lines. Those events probe the stellar intensity profile and could be used to measure limb darkening coefficients to test stellar model…

Instrumentation and Methods for Astrophysics · Physics 2019-08-14 Hans J. Witt , F. Atrio-Barandela

The linear inverse source and scattering problems are studied from the perspective of compressed sensing, in particular the idea that sufficient incoherence and sparsity guarantee uniqueness of the solution. By introducing the sensor as…

Data Analysis, Statistics and Probability · Physics 2009-05-19 Albert Fannjiang , Pengchong Yan , Thomas Strohmer

We develop a non--perturbative method that yields analytical expressions for the deflection angle of light in a general static and spherically symmetric metric. It is an improvement on a method previously devised by the authors, and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Paolo Amore , Mayra Cervantes , Arturo De Pace , Francisco M. Fernandez

This paper describes a linear solution method for near-light photometric stereo by exploiting symmetric light source arrangements. Unlike conventional non-convex optimization approaches, by arranging multiple sets of symmetric nearby light…

Computer Vision and Pattern Recognition · Computer Science 2026-03-18 Lilika Makabe , Heng Guo , Hiroaki Santo , Fumio Okura , Yasuyuki Matsushita

Lensless cameras relax the design constraints of traditional cameras by shifting image formation from analog optics to digital post-processing. While new camera designs and applications can be enabled, lensless imaging is very sensitive to…

Image and Video Processing · Electrical Eng. & Systems 2025-01-22 Eric Bezzam , Stefan Peters , Martin Vetterli

The inversion of a gravitational lens system is, as is well known, plagued by the so-called mass-sheet degeneracy: one can always rescale the density distribution of the lens and add a constant-density mass-sheet such that the, also…

Astrophysics · Physics 2009-11-13 J. Liesenborgs , S. De Rijcke , H. Dejonghe , P. Bekaert

A slab of negatively refracting material, thickness d, can focus an image at a distance 2d from the object. The negative slab cancels an equal thickness of positive space. This result is a special case of a much wider class of focussing:…

Condensed Matter · Physics 2009-11-10 J. B. Pendry , S. Anantha Ramakrishna

The spatial resolution of astronomical images is limited by atmospheric turbulence and diffraction in the telescope optics, resulting in blurred images. This makes it difficult to accurately measure the brightness of blended objects because…

Instrumentation and Methods for Astrophysics · Physics 2023-05-31 Kevin Michalewicz , Martin Millon , Frédéric Dux , Frédéric Courbin

Lensless microscopy with coherent or partially coherent light sources is a well known imaging technique, commonly referred as digital in-line holographic microscopy. In the established methods, both the spatial and temporal coherence of…

Optics · Physics 2020-11-04 Sanjeev Kumar , Manjunatha Mahadevappa , Pranab Kumar Dutta

Strong gravitational lensing is a powerful technique for probing galaxy mass distributions and for measuring cosmological parameters. We present a pixelated approach to modeling simultaneously the lens potential and source intensity of…

Analysis sparsity is a common prior in inverse problem or machine learning including special cases such as Total Variation regularization, Edge Lasso and Fused Lasso. We study the geometry of the solution set (a polyhedron) of the analysis…

Optimization and Control · Mathematics 2022-04-14 Xavier Dupuis , Samuel Vaiter

Natural signals and images are well-known to be approximately sparse in transform domains such as Wavelets and DCT. This property has been heavily exploited in various applications in image processing and medical imaging. Compressed sensing…

Machine Learning · Computer Science 2015-10-26 Saiprasad Ravishankar , Yoram Bresler

In this work we present relensing, a package written in python whose goal is to model galaxy clusters from gravitational lensing. With relensing we extend the amount of software available, which provides the scientific community with a wide…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-30 Daniel A. Torres-Ballesteros , Leonardo Castañeda

Least-squares reverse time migration is well-known for its capability to generate artifact-free true-amplitude subsurface images through fitting observed data in the least-squares sense. However, when applied to realistic imaging problems,…

Geophysics · Physics 2020-03-04 Mengmeng Yang , Zhilong Fang , Philipp Witte , Felix J. Herrmann

It is now well understood that (1) it is possible to reconstruct sparse signals exactly from what appear to be highly incomplete sets of linear measurements and (2) that this can be done by constrained L1 minimization. In this paper, we…

Methodology · Statistics 2007-11-13 Emmanuel J. Candes , Michael B. Wakin , Stephen P. Boyd