no code implementations • 4 Dec 2023 • Matthieu Terris, Thomas Moreau, Nelly Pustelnik, Julian Tachella
Plug-and-play algorithms constitute a popular framework for solving inverse imaging problems that rely on the implicit definition of an image prior via a denoiser.
no code implementations • 6 Aug 2023 • Hoang Trieu Vy Le, Audrey Repetti, Nelly Pustelnik
In particular, proximal neural networks (PNNs) have been introduced, obtained by unrolling a proximal algorithm as for finding a MAP estimate, but over a fixed number of iterations, with learned linear operators and parameters.
1 code implementation • 17 Mar 2022 • Gersende Fort, Barbara Pascal, Patrice Abry, Nelly Pustelnik
The originality of the devised algorithms stems from combining a Langevin Monte Carlo sampling scheme with Proximal operators.
no code implementations • 20 Feb 2022 • Mingyuan Jiu, Nelly Pustelnik
Preliminary experiments illustrate the good behavior of such a deep primal-dual network in the context of image restoration on BSD68 database.
no code implementations • 11 Feb 2022 • Patrice Abry, Gersende Fort, Barbara Pascal, Nelly Pustelnik
Yet, the assessment of the pandemic intensity within the pandemic period remains a challenging task because of the limited quality of data made available by public health authorities (missing data, outliers and pseudoseasonalities, notably), that calls for cumbersome and ad-hoc preprocessing (denoising) prior to estimation.
1 code implementation • 28 Sep 2021 • Charles-Gérard Lucas, Barbara Pascal, Nelly Pustelnik, Patrice Abry
This work focuses on a parameter-free joint piecewise smooth image denoising and contour detection.
no code implementations • 20 Sep 2021 • Barbara Pascal, Patrice Abry, Nelly Pustelnik, Stéphane G. Roux, Rémi Gribonval, Patrick Flandrin
The present work aims to overcome these limitations by carefully crafting a functional permitting to estimate jointly, in a single step, the reproduction number and outliers defined to model low quality data.
no code implementations • 2 Jul 2020 • Mingyuan Jiu, Nelly Pustelnik
In this work, we design a deep network, named DeepPDNet, built from primal-dual proximal iterations associated with the minimization of a standard penalized likelihood with an analysis prior, allowing us to take advantage of both worlds.
no code implementations • 20 Apr 2020 • Barbara Pascal, Samuel Vaiter, Nelly Pustelnik, Patrice Abry
This work extends the Stein's Unbiased GrAdient estimator of the Risk of Deledalle et al. to the case of correlated Gaussian noise, deriving a general automatic tuning of regularization parameters.
1 code implementation • 31 Oct 2019 • Raimon Fabregat, Nelly Pustelnik, Paulo Gonçalves, Pierre Borgnat
Non-negative matrix factorization is a problem of dimensionality reduction and source separation of data that has been widely used in many fields since it was studied in depth in 1999 by Lee and Seung, including in compression of data, document clustering, processing of audio spectrograms and astronomy.
1 code implementation • 22 May 2017 • Mingyuan Jiu, Nelly Pustelnik, Stefan Janaqi, Mériam Chebre, Lin Qi, Philippe Ricoux
This work focuses on learning optimization problems with quadratical interactions between variables, which go beyond the additive models of traditional linear learning.
no code implementations • 27 Aug 2016 • Jordan Frecon, Nelly Pustelnik, Nicolas Dobigeon, Herwig Wendt, Patrice Abry
Piecewise constant denoising can be solved either by deterministic optimization approaches, based on the Potts model, or by stochastic Bayesian procedures.
no code implementations • 22 Apr 2015 • Jordan Frecon, Nelly Pustelnik, Patrice Abry, Laurent Condat
In the context of change-point detection, addressed by Total Variation minimization strategies, an efficient on-the-fly algorithm has been designed leading to exact solutions for univariate data.
no code implementations • 22 Apr 2015 • Nelly Pustelnik, Herwig Wendt, Patrice Abry, Nicolas Dobigeon
Texture segmentation constitutes a standard image processing task, crucial to many applications.
no code implementations • 15 Jan 2015 • G. Chierchia, Nelly Pustelnik, Jean-Christophe Pesquet, B. Pesquet-Popescu
In this paper, we propose a convex optimization approach for efficiently and exactly solving the multiclass SVM learning problem involving a sparse regularization and the multiclass hinge loss formulated by Crammer and Singer.
no code implementations • 21 Mar 2014 • Giovanni Chierchia, Nelly Pustelnik, Beatrice Pesquet-Popescu, Jean-Christophe Pesquet
In this paper, we extend the NLTV-based regularization to multicomponent images by taking advantage of the Structure Tensor (ST) resulting from the gradient of a multicomponent image.