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In this work, a method for obtaining pixel-wise error bounds in Bayesian regularization of inverse imaging problems is introduced. The proposed method employs estimates of the posterior variance together with techniques from conformal…

Computer Vision and Pattern Recognition · Computer Science 2024-08-01 Dominik Narnhofer , Andreas Habring , Martin Holler , Thomas Pock

Diffusion models have established new state of the art in a multitude of computer vision tasks, including image restoration. Diffusion-based inverse problem solvers generate reconstructions of exceptional visual quality from heavily…

Image and Video Processing · Electrical Eng. & Systems 2024-08-21 Zalan Fabian , Berk Tinaz , Mahdi Soltanolkotabi

This paper is devoted to the problem of determining the concentration bounds that are achievable in non-parametric regression. We consider the setting where features are supported on a bounded subset of $\mathbb{R}^d$, the regression…

Statistics Theory · Mathematics 2024-12-02 Anna Ben-Hamou , Arnaud Guyader

This work describes a Bayesian framework for reconstructing the boundaries that represent targeted features in an image, as well as the regularity (i.e., roughness vs. smoothness) of these boundaries.This regularity often carries crucial…

Numerical Analysis · Mathematics 2024-01-26 Babak Maboudi Afkham , Nicolai André Brogaard Riis , Yiqiu Dong , Per Christian Hansen

We consider the inverse problem of retrieving aerosol extinction coefficients from Raman lidar measurements. In this problem the unknown and the data are related through the exponential of a linear operator, the unknown is non-negative and…

Numerical Analysis · Mathematics 2018-08-21 Giulia Denevi , Sara Garbarino , Alberto Sorrentino

Denoising diffusion models are a novel class of generative algorithms that achieve state-of-the-art performance across a range of domains, including image generation and text-to-image tasks. Building on this success, diffusion models have…

Machine Learning · Computer Science 2024-03-08 Nic Fishman , Leo Klarner , Valentin De Bortoli , Emile Mathieu , Michael Hutchinson

We aim at the development and analysis of the numerical schemes for approximately solving the backward diffusion-wave problem, which involves a fractional derivative in time with order $\alpha\in(1,2)$. From terminal observations at two…

Numerical Analysis · Mathematics 2021-09-16 Zhengqi Zhang , Zhi Zhou

Diffusion tensor imaging (DTI) holds significant importance in clinical diagnosis and neuroscience research. However, conventional model-based fitting methods often suffer from sensitivity to noise, leading to decreased accuracy in…

Computer Vision and Pattern Recognition · Computer Science 2024-09-05 Jialong Li , Zhicheng Zhang , Yunwei Chen , Qiqi Lu , Ye Wu , Xiaoming Liu , QianJin Feng , Yanqiu Feng , Xinyuan Zhang

Solving inverse problems involving measurement noise and modeling errors requires regularization in order to avoid data overfit. Geophysical inverse problems, in which the Earth's highly heterogeneous structure is unknown, present a…

Geophysics · Physics 2022-03-31 Ali Siahkoohi , Rafael Orozco , Gabrio Rizzuti , Felix J. Herrmann

Although diffusion models (DMs) have shown promising performances in a number of tasks (e.g., speech synthesis and image generation), they might suffer from error propagation because of their sequential structure. However, this is not…

Machine Learning · Computer Science 2024-01-19 Yangming Li , Mihaela van der Schaar

Inverse problems and regularization theory is a central theme in contemporary signal processing, where the goal is to reconstruct an unknown signal from partial indirect, and possibly noisy, measurements of it. A now standard method for…

Optimization and Control · Mathematics 2014-12-09 Samuel Vaiter , Gabriel Peyré , Jalal M. Fadili

Diffusion models trained on different, non-overlapping subsets of a dataset often produce strikingly similar outputs when given the same noise seed. We trace this consistency to a simple linear effect: the shared Gaussian statistics across…

Machine Learning · Computer Science 2026-02-04 Binxu Wang , Jacob Zavatone-Veth , Cengiz Pehlevan

The original motivation for this paper was to provide an efficient quantitative analysis of convex infinite (or semi-infinite) inequality systems whose decision variables run over general infinite-dimensional (resp. finite-dimensional)…

Optimization and Control · Mathematics 2011-02-11 M. J. Cánovas , M. A. LóPez , B. S. Mordukhovich , J. Parra

There are various inverse problems -- including reconstruction problems arising in medical imaging -- where one is often aware of the forward operator that maps variables of interest to the observations. It is therefore natural to ask…

Image and Video Processing · Electrical Eng. & Systems 2020-06-23 Jaweria Amjad , Zhaoyan Lyu , Miguel R. D. Rodrigues

We consider the numerical solution of time-harmonic acoustic scattering by obstacles with uncertain geometries for Dirichlet, Neumann, impedance and transmission boundary conditions. In particular, we aim to quantify diffracted fields…

Numerical Analysis · Mathematics 2020-02-13 Paul Escapil-Inchauspé , Carlos Jerez-Hanckes

This paper provides a unified framework for analyzing tensor estimation problems that allow for nonlinear observations, heteroskedastic noise, and covariate information. We study a general class of high-dimensional models where each…

Information Theory · Computer Science 2025-06-10 Riccardo Rossetti , Galen Reeves

Diffusion models are typically trained using pointwise reconstruction objectives that are agnostic to the spectral and multi-scale structure of natural signals. We propose a loss-level spectral regularization framework that augments…

Machine Learning · Computer Science 2026-03-04 Satish Chandran , Nicolas Roque dos Santos , Yunshu Wu , Greg Ver Steeg , Evangelos Papalexakis

A supervised learning approach is proposed for regularization of large inverse problems where the main operator is built from noisy data. This is germane to superresolution imaging via the sampling indicators of the inverse scattering…

Numerical Analysis · Mathematics 2025-08-22 Fatemeh Pourahmadian , Yang Xu

In recent years, Diffusion Models have become the new state-of-the-art in deep generative modeling, ending the long-time dominance of Generative Adversarial Networks. Inspired by the Regularization by Denoising principle, we introduce an…

Image and Video Processing · Electrical Eng. & Systems 2025-03-31 Pasquale Cascarano , Lorenzo Stacchio , Andrea Sebastiani , Alessandro Benfenati , Ulugbek S. Kamilov , Gustavo Marfia

Incorporating diffusion models in the image compression domain has the potential to produce realistic and detailed reconstructions, especially at extremely low bitrates. Previous methods focus on using diffusion models as expressive…

Image and Video Processing · Electrical Eng. & Systems 2024-10-10 Lucas Relic , Roberto Azevedo , Markus Gross , Christopher Schroers