English
Related papers

Related papers: From constant to variable density inverse extended…

200 papers

Inverse problems generally require a regularizer or prior for a good solution. A recent trend is to train a convolutional net to denoise images, and use this net as a prior when solving the inverse problem. Several proposals depend on a…

Computer Vision and Pattern Recognition · Computer Science 2023-07-12 Kyle Luther , H. Sebastian Seung

We consider debiased inference on finite-dimensional functionals of infinite-dimensional least-squares solutions to inverse problems as a way to avoid having to assume exact solutions exist. Such assumptions are substantive and not…

Machine Learning · Statistics 2026-05-27 Zikai Shen , Nathan Kallus , Dimitri Meunier , Houssam Zenati , Arthur Gretton , Aurélien Bibaut

Previous research on late-reverberation modeling has mainly focused on exponentially decaying room impulse responses, whereas methods for accurately modeling non-exponential reverberation remain challenging. This paper extends the…

Audio and Speech Processing · Electrical Eng. & Systems 2024-04-02 Jon Fagerström , Sebastian J. Schlecht , Vesa Välimäki

We propose an image deconvolution algorithm when the data is contaminated by Poisson noise. The image to restore is assumed to be sparsely represented in a dictionary of waveforms such as the wavelet or curvelet transform. Our key…

Optimization and Control · Mathematics 2008-03-25 François-Xavier Dupé , Jalal Fadili , Jean Luc Starck

We solve the compressive sensing problem via convolutional factor analysis, where the convolutional dictionaries are learned {\em in situ} from the compressed measurements. An alternating direction method of multipliers (ADMM) paradigm for…

Machine Learning · Statistics 2017-01-12 Xin Yuan , Yunchen Pu , Lawrence Carin

This paper is concerned with an inverse random source problem for the one-dimensional stochastic Helmholtz equation with attenuation. The source is assumed to be a microlocally isotropic Gaussian random field with its covariance operator…

Numerical Analysis · Mathematics 2020-09-30 Peijun Li , Xu Wang

Diffusion models have made remarkable progress in solving various inverse problems, attributing to the generative modeling capability of the data manifold. Posterior sampling from the conditional score function enable the precious data…

Computer Vision and Pattern Recognition · Computer Science 2024-07-16 Jinghao Zhang , Zizheng Yang , Qi Zhu , Feng Zhao

Employing a forward diffusion chain to gradually map the data to a noise distribution, diffusion-based generative models learn how to generate the data by inferring a reverse diffusion chain. However, this approach is slow and costly…

Machine Learning · Statistics 2023-09-08 Huangjie Zheng , Pengcheng He , Weizhu Chen , Mingyuan Zhou

This paper addresses the issue of inversion in cases where (1) the observation system is modeled by a linear transformation and additive noise, (2) the problem is ill-posed and regularization is introduced in a Bayesian framework by an a…

Machine Learning · Statistics 2026-02-12 Jean-François Giovannelli

Ill-posed imaging inverse problems remain challenging due to the ambiguity in mapping degraded observations to clean images. Diffusion-based generative priors have recently shown promise, but typically rely on computationally intensive…

Image and Video Processing · Electrical Eng. & Systems 2026-02-13 Ayush Varshney , Katherine L. Bouman , Berthy T. Feng

We study an inverse random obstacle scattering problems in $\mathbb{R}^2$ where the scatterer is formulated by a Gaussian process defined on the angular parameter domain. Equipped with a modified covariance function which is mathematically…

Numerical Analysis · Mathematics 2026-02-02 Zhiqi Sun , Xiang Xu , Yiwen Lin

Diffusion models have gained attention for their ability to represent complex distributions and incorporate uncertainty, making them ideal for robust predictions in the presence of noisy or incomplete data. In this study, we develop and…

Machine Learning · Computer Science 2024-11-05 Yilin Zhuang , Sibo Cheng , Karthik Duraisamy

This study focuses on the application of ultra sonic diffrac tion tomography to noncircular 2D-cylindri - cal ob jects im mersed in an in fi nite fluid. The dis torted Born it er a tive method used to solve the in verse scat ter ing prob…

Classical Physics · Physics 2009-12-17 Philippe Lasaygues , Régine Guillermin , Jean-Pierre Lefebvre

Contrary to the traditional pursuit of research on nonuniform sampling of bandlimited signals, the objective of the present paper is not to find sampling conditions that permit perfect reconstruction, but to perform the best possible signal…

Signal Processing · Electrical Eng. & Systems 2024-04-05 Nguyen T. Thao , Dominik Rzepka , Marek Miskowicz

Time reversal (TR) focusing of ultrasound in granular packings is experimentally investigated. Pulsed elastic waves transmitted from a compressional or shear transducer source are measured by a TR mirror, reversed in time and…

Soft Condensed Matter · Physics 2019-12-18 Maxime Harazi , Yougu Yang , Mathias Fink , Arnaud Tourin , Xiaoping Jia

The Extended Randomized Kaczmarz method is a well known iterative scheme which can find the Moore-Penrose inverse solution of a possibly inconsistent linear system and requires only one additional column of the system matrix in each…

Numerical Analysis · Mathematics 2022-07-21 Frank Schöpfer , Dirk A Lorenz , Lionel Tondji , Maximilian Winkler

When the inverse problem of diffuse optical tomography (DOT) is solved with the Born or Rytov approximation, the size of the matrix of the linear inverse problem becomes large if the volume (or area) of the domain in biological tissue used…

Medical Physics · Physics 2021-07-22 Tetsuya Mimura , Yu Jiang , Norikazu Todoroki , Manabu Machida

We establish results for the injectivity and injectivity modulo gauge of certain inverse source problems in transport on a simply connected domain with variable index of refraction inducing a 'simple geometry'. The model given by radiative…

Analysis of PDEs · Mathematics 2019-08-20 Guillaume Bal , François Monard

We propose an improved density integration methodology for Background Oriented Schlieren (BOS) measurements that overcomes the noise sensitivity of the commonly used Poisson solver. The method employs a weighted least-squares (WLS)…

Fluid Dynamics · Physics 2020-12-02 Lalit Rajendran , Jiacheng Zhang , Sally Bane , Pavlos Vlachos

In seismic exploration, sources and measurements of seismic waves on the surface are used to determine model parameters representing geophysical properties of the earth. Full-waveform inversion (FWI) is a nonlinear seismic inverse technique…

Numerical Analysis · Mathematics 2019-02-05 Yunan Yang