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Photoacoustic tomography is a hybrid imaging technique that combines high optical tissue contrast with high ultrasound resolution. Direct reconstruction methods such as filtered backprojection, time reversal and least squares suffer from…

For some typical and widely used non-convex half-quadratic regularization models and the Ambrosio-Tortorelli approximate Mumford-Shah model, based on the Kurdyka-\L ojasiewicz analysis and the recent nonconvex proximal algorithms, we…

Optimization and Control · Mathematics 2021-07-30 Shengxiang Deng , Ismail Ben Ayed , Hongpeng Sun

Phase retrieval is a nonlinear inverse problem that arises in a wide range of imaging modalities, from electron microscopy to Fourier ptychography. In particular, the reconstruction is facilitated when the sensing matrix is i.i.d. random,…

In computed tomography (CT), the forward model consists of a linear Radon transform followed by an exponential nonlinearity based on the attenuation of light according to the Beer-Lambert Law. Conventional reconstruction often involves…

Computer Vision and Pattern Recognition · Computer Science 2026-03-25 Sara Fridovich-Keil , Fabrizio Valdivia , Gordon Wetzstein , Benjamin Recht , Mahdi Soltanolkotabi

Camera anomalies like rain or dust can severelydegrade image quality and its related tasks, such as localizationand segmentation. In this work we address this importantissue by implementing a pre-processing step that can effectivelymitigate…

Computer Vision and Pattern Recognition · Computer Science 2021-09-07 Gianmario Fumagalli , Yannick Huber , Marcin Dymczyk , Roland Siegwart , Renaud Dubé

Indirect image registration is a promising technique to improve image reconstruction quality by providing a shape prior for the reconstruction task. In this paper, we propose a novel hybrid method that seeks to reconstruct high quality…

Image and Video Processing · Electrical Eng. & Systems 2019-12-18 Jiulong Liu , Angelica I. Aviles-Rivero , Hui Ji , Carola-Bibiane Schönlieb

This work investigates the acceleration of MPGP-type algorithms using preconditioning for the solution of quadratic programming problems. The preconditioning needs to be done only on the free set so as not to change the constraints. A…

Numerical Analysis · Mathematics 2026-05-19 Jakub Kružík , David Horák

In this paper we propose to use model reduction techniques for speeding up the diagonalization-based parallel-in-time (ParaDIAG) preconditioner, for iteratively solving all-at-once systems from evolutionary PDEs. In particular, we use the…

Numerical Analysis · Mathematics 2020-12-17 Jun Liu , Zhu Wang

The goal of this work is to present a fast and viable approach for the numerical solution of the high-contrast state problems arising in topology optimization. The optimization process is iterative, and the gradients are obtained by an…

Numerical Analysis · Mathematics 2020-06-25 Miguel Zambrano , Sintya Serrano , Boyan S. Lazarov , Juan Galvis

Image restoration problems are typically ill-posed requiring the design of suitable priors. These priors are typically hand-designed and are fully instantiated throughout the process. In this paper, we introduce a novel framework for…

Computer Vision and Pattern Recognition · Computer Science 2019-03-19 Raied Aljadaany , Dipan K. Pal , Marios Savvides

Diffusion models have gained significant popularity in the field of image-to-image translation. Previous efforts applying diffusion models to image super-resolution (SR) have demonstrated that iteratively refining pure Gaussian noise using…

Computer Vision and Pattern Recognition · Computer Science 2023-07-04 Axi Niu , Pham Xuan Trung , Kang Zhang , Jinqiu Sun , Yu Zhu , In So Kweon , Yanning Zhang

Tomographic image sizes keep increasing over time and while the GPUs that compute the tomographic reconstruction are also increasing in memory size, they are not doing so fast enough to reconstruct the largest datasets. This problem is…

Distributed, Parallel, and Cluster Computing · Computer Science 2019-05-10 Ander Biguri , Reuben Lindroos , Robert Bryll , Hossein Towsyfyan , Hans Deyhle , Richard Boardman , Mark Mavrogordato , Manjit Dosanjh , Steven Hancock , Thomas Blumensath

Deep learning-based methods have revolutionized the field of imaging inverse problems, yielding state-of-the-art performance across various imaging domains. The best performing networks incorporate the imaging operator within the network…

Computer Vision and Pattern Recognition · Computer Science 2026-01-06 Romain Vo , Julián Tachella

Neural implicit modeling permits to achieve impressive 3D reconstruction results on small objects, while it exhibits significant limitations in large indoor scenes. In this work, we propose a novel neural implicit modeling method that…

Computer Vision and Pattern Recognition · Computer Science 2023-09-14 Federico Lincetto , Gianluca Agresti , Mattia Rossi , Pietro Zanuttigh

Recovering high-dimensional statistical structure from limited measurements is a fundamental challenge in hyperspectral imaging, where capturing full-resolution data is often infeasible due to sensor, bandwidth, or acquisition constraints.…

Image and Video Processing · Electrical Eng. & Systems 2025-08-01 Jonathan Monsalve , Kumar Vijay Mishra

Reduced-order simulation is an emerging method for accelerating physical simulations with high DOFs, and recently developed neural-network-based methods with nonlinear subspaces have been proven effective in diverse applications as more…

Machine Learning · Computer Science 2024-09-09 Aoran Lyu , Shixian Zhao , Chuhua Xian , Zhihao Cen , Hongmin Cai , Guoxin Fang

Efficient simulation of nonlinear and dispersive free-surface flows governed by the incompressible Navier-Stokes equations remains a central challenge in ocean and coastal engineering. The computational bottleneck arises from solving a…

Although some preconditioners are available for solving dense linear systems, there are still many matrices for which preconditioners are lacking, in particular in cases where the size of the matrix $N$ becomes very large. There remains…

Numerical Analysis · Mathematics 2016-02-05 Pieter Coulier , Hadi Pouransari , Eric Darve

Learned progressive image compression is gaining momentum as it allows improved image reconstruction as more bits are decoded at the receiver. We propose a progressive image compression method in which an image is first represented as a…

Computer Vision and Pattern Recognition · Computer Science 2025-01-13 Alberto Presta , Enzo Tartaglione , Attilio Fiandrotti , Marco Grangetto , Pamela Cosman

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…

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