Some Contributions to Reconstruction Problems
Data-driven modelling of ground-based and space-based telescope's point spread functions
Gravitational lensing is the distortion of the images of distant galaxies by intervening massive objects and constitutes a powerful probe of the Large Scale Structure of our Universe. Cosmologists use weak (gravitational) lensing to study the nature of dark matter and its spatial distribution. These studies require highly accurate measurements of g...
Advanced deep neural networks for MRI image reconstruction from highly undersampled data in challenging acquisition sett...
Magnetic Resonance Imaging (MRI) is one of the most prominent imaging techniques in the world. Its main purpose is to probe soft tissues in a non-invasive and non-ionizing way. However, its wider adoption is hindered by an overall high scan time. In order to reduce this duration, several approaches have been proposed, among which Parallel Imaging (...
Enabling cortical cell-specific sensitivity on diffusion MRI microstructure measurements using likelihood-free inference...
Neurodegenerative diseases, such as Alzheimer's or Huntington's disease, lead to the progressive and irreversible loss of mental functions. Dementia and cognitive deficits appear to be primarily related to neuronal and synaptic connectivity loss. Although these diseases' external impact and progression are readily observable, accessing microstructu...
Bayesian Plug & Play Methods for Inverse Problems in Imaging
This thesis deals with Bayesian methods for solving ill-posed inverse problems in imaging with learnt image priors. The first part of this thesis (Chapter 3) concentrates on two particular problems, namely joint denoising and decompression and multi-image super-resolution. After an extensive study of the noise statistics for these problem in the tr...
Single-pixel imaging : compressed video acquisition and reconstruction using Deep learning
Single-pixel cameras allow acquisition of two-dimensional images using only a single-point detector. These use hardware to measure the inner product of the scene under view, along with the user-defined functions, and then the image is recovered using reconstruction algorithms. Single-pixel cameras are well suited for imaging problems where it might...
Échantillonnage stochastique efficace par modèle Bernoulli mélange de Gaussiennes pour la résolution des problèmes inver...
Cette thèse aborde la résolution des problèmes inverses parcimonieux quand les données observées peuvent être considérées comme une combinaison linéaire d'un faible nombre d'éléments dits « atomes » (e.g., impulsions, réponse instrumentale décalée ou sinusoïdes). Ces problèmes sont rencontrés dans différents domaines d'application, allant du contrô...
Model Based Signal Processing Techniques for Nonconventional Optical Imaging Systems
There is an increasing demand for images with higher spectral and spatial resolution for applications in several domains such as health, environment, quality checking and natural disasters monitoring. Hyperspectral imagery provides the necessary spectral diversity to recover the composition of materials on site for applications such as the detectio...
Reconstruction hyperspectrale haute résolution par inversion de mesures spectroscopiques à integrale de champ. Applicati...
Cette thèse traite des approches de type problème inverse pour reconstruire une image 3D spatio-spectrale (2D+λ) à partir d’un ensemble de mesures infrarouges 2D fournies par l’instrument “Integral Field Spectrometer” (IFS) (Mid-ResolutionSpectrometer: MRS) de l’instrument “Mid-Infrared” à bord du “James Webb Space Telescope” (JWST). Plusieurs diff...
Méthodes d'imagerie ultrasonore avancées et rapides pour le contrôle non destructif de matériaux atténuants et diffusant...
Le developpement de sondes multielements et les progres continus en electronique ont favorise l’emergence des methodes d’imagerie ultrasonore pour le controle non-destructif (CND). En particulier, les approches lineaires de type formation de voies sont largement utilisees pour leur simplicite et leur rapidite, rendant possible l’imagerie en temps r...
