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Related papers: Alternating Projection, Ptychographic Imaging and …

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In this paper, we extend the previous convergence results for the generalized alternating projection method applied to subspaces in [arXiv:1703.10547] to hold also for smooth manifolds. We show that the algorithm locally behaves similarly…

Optimization and Control · Mathematics 2024-04-10 Mattias Fält , Pontus Giselsson

Time-of-flight cameras provide depth information, which is complementary to the photometric appearance of the scene in ordinary images. It is desirable to merge the depth and colour information, in order to obtain a coherent scene…

Computer Vision and Pattern Recognition · Computer Science 2020-12-18 Miles Hansard , Georgios Evangelidis , Quentin Pelorson , Radu Horaud

Kaczmarz's alternating projection method has been widely used for solving a consistent (mostly over-determined) linear system of equations Ax=b. Because of its simple iterative nature with light computation, this method was successfully…

Numerical Analysis · Computer Science 2014-07-22 Tim Wallace , Ali Sekmen

Fourier Ptychography is a recently proposed imaging technique that yields high-resolution images by computationally transcending the diffraction blur of an optical system. At the crux of this method is the phase retrieval algorithm, which…

Computer Vision and Pattern Recognition · Computer Science 2018-05-10 Lokesh Boominathan , Mayug Maniparambil , Honey Gupta , Rahul Baburajan , Kaushik Mitra

X-ray ptychography utilizes overlapping illuminations to reconstruct the object's phase and absorption signal with spatial resolutions much smaller than the focus size. Usually, the illumination overlap is chosen to be between 50% and 60%…

Materials Science · Physics 2022-07-29 Felix Wittwer , Peter Modregger

Numerical Simulation is an essential part of the design and optimisation of astronomical adaptive optics systems. Simulations of adaptive optics are computationally expensive and the problem scales rapidly with telescope aperture size, as…

Astrophysics · Physics 2009-11-13 A. G. Basden , F. Assemat , T. Butterley , D. Geng , C. D. Saunter , R. W. Wilson

Adaptive optics can be used to mitigate the effects of atmospheric turbulence on imaging systems, but the correction is only partial, and deconvolution is often required to improve the resolution. This results in entire optical/digital…

Instrumentation and Methods for Astrophysics · Physics 2026-02-09 Florian Cheyssial , Laurent Mugnier , Cyril Petit

Suppose we are given a system of coupled oscillators on an unknown graph along with the trajectory of the system during some period. Can we predict whether the system will eventually synchronize? Even with a known underlying graph…

Dynamical Systems · Mathematics 2022-08-25 Hardeep Bassi , Richard Yim , Rohith Kodukula , Joshua Vendrow , Cherlin Zhu , Hanbaek Lyu

We consider a variational method to solve the optical flow problem with varying illumination. We apply an adaptive control of the regularization parameter which allows us to preserve the edges and fine features of the computed flow. To…

Computer Vision and Pattern Recognition · Computer Science 2015-08-13 Diane Gilliocq-Hirtz , Zakaria Belhachmi

We present an end-to-end automated workflow that uses large-scale remote compute resources and an embedded GPU platform at the edge to enable AI/ML-accelerated real-time analysis of data collected for x-ray ptychography. Ptychography is a…

Computer Vision and Pattern Recognition · Computer Science 2023-04-11 Anakha V Babu , Tekin Bicer , Saugat Kandel , Tao Zhou , Daniel J. Ching , Steven Henke , Siniša Veseli , Ryan Chard , Antonino Miceli , Mathew Joseph Cherukara

We study the alternating algorithm for the computation of the metric projection onto the closed sum of two closed subspaces in uniformly convex and uniformly smooth Banach spaces. For Banach spaces which are convex and smooth of power type,…

Functional Analysis · Mathematics 2020-10-09 Christian Bargetz , Emir Medjic

The paper addresses the problem of energy compaction of dense 4D light fields by designing geometry-aware local graph-based transforms. Local graphs are constructed on super-rays that can be seen as a grouping of spatially and…

Computer Vision and Pattern Recognition · Computer Science 2019-10-23 Mira Rizkallah , Xin Su , Thomas Maugey , Christine Guillemot

In this work, we present and investigate the novel blind inverse problem of position-blind ptychography, i.e., ptychographic phase retrieval without any knowledge of scan positions, which then must be recovered jointly with the image. The…

Image and Video Processing · Electrical Eng. & Systems 2026-03-18 Simon Welker , Lorenz Kuger , Tim Roith , Berthy Feng , Martin Burger , Timo Gerkmann , Henry Chapman

Iterative ptychographic reconstruction algorithms are widely used for coherent diffractive imaging but can exhibit slow convergence under realistic experimental conditions. We propose a machine learning-augmented approach that accelerates…

Ptychography is a powerful imaging technique that is used in a variety of fields, including materials science, biology, and nanotechnology. However, the accuracy of the reconstructed ptychography image is highly dependent on the accuracy of…

Applied Physics · Physics 2024-06-03 Ming Du , Tao Zhou , Junjing Deng , Daniel J. Ching , Steven Henke , Mathew J. Cherukara

Ptychography is a powerful computational imaging technique that transforms a collection of low-resolution images into a high-resolution sample reconstruction. Unfortunately, algorithms that are currently used to solve this reconstruction…

We study the problem of synchronizing a general complex network by means of an adaptive strategy in the case where the network topology is slowly time varying and every node receives at each time only one aggregate signal from the set of…

Disordered Systems and Neural Networks · Physics 2009-11-13 Francesco Sorrentino , Edward Ott

Reconstructing the 3D model of a physical object typically requires us to align the depth scans obtained from different camera poses into the same coordinate system. Solutions to this global alignment problem usually proceed in two steps.…

Computer Vision and Pattern Recognition · Computer Science 2019-06-05 Xiangru Huang , Zhenxiao Liang , Xiaowei Zhou , Yao Xie , Leonidas Guibas , Qixing Huang

In 1997, Bauschke, Borwein, and Lewis have stated a trichotomy theorem that characterizes when the convergence of the method of alternating projections can be arbitrarily slow. However, there are two errors in their proof of this theorem.…

Functional Analysis · Mathematics 2007-10-15 H. H. Bauschke , F. Deutsch , H. Hundal

Two algorithms for solving misalignment issues in penalized PET/CT reconstruction using anatomical priors are proposed. Both approaches are based on a recently published joint motion estimation and image reconstruction method. The first…

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