Publications de Julien René Pierre Fageot

PolyCLEAN: Atomic optimization for super-resolution imaging and uncertainty estimation in radio interferometry

Sepand Kashani, Adrian Thibault Etienne Jarret, Matthieu Martin Jean-André Simeoni, Julien René Pierre Fageot, Joan Rue Queralt

Context. Imaging in radio interferometry requires solving an ill-posed noisy inverse problem, for which the most adopted algorithm is the original CLEAN algorithm and its variants. Alternative explicit optimization methods have gained increasing attention, ...

EDP SCIENCES S A2025

Convergence analysis of the discretization of continuous-domain inverse problems

Michaël Unser, Julien René Pierre Fageot

We study continuous-domain linear inverse problems that involve a general data-fidelity term and a regularisation term. We consider a regularisation that is formed by the sparsity-promoting total-variation norm, pre-composed with a differential operator th ...

2025

Generalized Bradley-Terry Models for Score Estimation from Paired Comparisons

Sadegh Farhadkhani, Oscar Jean Olivier Villemaud, Julien René Pierre Fageot, Le Nguyen Hoang

Many applications, e.g. in content recommendation, sports, or recruitment, leverage the comparisons of alternatives to score those alternatives. The classical Bradley-Terry model and its variants have been widely used to do so. The historical model conside ...

AAAI Press2024

A Decoupled Approach for Composite Sparse-plus-Smooth Penalized Optimization

Adrian Thibault Etienne Jarret, Julien René Pierre Fageot

We consider a linear inverse problem whose solution is expressed as a sum of two components: one smooth and the other sparse. This problem is addressed by minimizing an objective function with a least squares data-fidelity term and a different regularizati ...

2024

Complex-order scale-invariant operators and self-similar processes

Michaël Unser, Julien René Pierre Fageot

In this paper, we perform the joint study of scale -invariant operators and self -similar processes of complex order. More precisely, we introduce general families of scale -invariant complex -order fractional -derivation and integration operators by const ...

Academic Press Inc Elsevier Science2024

Comparing various AI approaches to traditional quantitative assessment of the myocardial perfusion in [82Rb] PET for MACE prediction

Julien René Pierre Fageot, Adrien Raphaël Depeursinge, Daniel Abler

Assessing the individual risk of Major Adverse Cardiac Events (MACE) is of major importance as cardiovascular diseases remain the leading cause of death worldwide. Quantitative Myocardial Perfusion Imaging (MPI) parameters such as stress Myocardial Blood F ...

Nature Portfolio2024

TV-based spline reconstruction with Fourier measurements: Uniqueness and convergence of grid-based methods

Julien René Pierre Fageot, Thomas Jean Debarre, Quentin Alain Denoyelle

We study the problem of recovering piecewise-polynomial periodic functions from their low-frequency information. This means that we only have access to possibly corrupted versions of the Fourier samples of the ground truth up to a maximum cutoff frequency ...

ELSEVIER2023

Une version polyatomique de l'algorithme Frank-Wolfe pour résoudre le problème LASSO en grandes dimensions

Adrian Thibault Etienne Jarret, Matthieu Martin Jean-André Simeoni, Julien René Pierre Fageot

Nous nous intéressons à la reconstruction parcimonieuse d’images à l’aide du problème d’optimisation régularisé LASSO. Dans de nombreuses applications pratiques, les grandes dimensions des objets à reconstruire limitent, voire empêchent, l’utilisation des ...

2022

Entropic Compressibility of Levy Processes

Julien René Pierre Fageot

In contrast to their seemingly simple and shared structure of independence and stationarity, Levy processes exhibit a wide variety of behaviors, from the self-similar Wiener process to piecewise-constant compound Poisson processes. Inspired by the recent p ...

2022

Steer'n'Detect: fast 2D template detection with accurate orientation estimation

Michaël Unser, Daniel Sage, Zsuzsanna Püspöki, Julien René Pierre Fageot

Motivation: Rotated template matching is an efficient and versatile algorithm to analyze microscopy images, as it automates the detection of stereotypical structures, such as organelles that can appear at any orientation. Its performance however quickly de ...

2022