Pierre Vandergheynst

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This paper reviews the application of a novel methodology for analysing the isotropy of the universe by probing the alignment of local structures in the CMB. The strength of the proposed methodology relies on the steerable wavelet filtering of the CMB sign ...

Le modele des contours actifs [6,2,7] est un des modeles variationnels de segmentation les plus connus en traitement d'images. Cependant, ce modele est limite par l'existence de minima locaux qui rend la condition initiale critique pour obtenir des resulta ...

We consider images probed through incomplete and noisy Fourier coverages, both in the context of radio interferometry (RI) and of magnetic resonance imaging (MRI). We show that the quality of signal reconstruction can be signiﬁcantly enhanced by the introd ...

An algorithm is proposed for denoising the signal induced by cosmic strings in the cosmic microwave background (CMB). A Bayesian approach is taken, based on modeling the string signal in the wavelet domain with generalized Gaussian distributions. Good perf ...

We cast the problem of source localization on graphs as the simultaneous problem of sparse recovery and diffusion ker- nel learning. An l1 regularization term enforces the sparsity constraint while we recover the sources of diffusion from a single snapshot ...

A new generation of optical devices that generate images covering a larger part of the field of view than conventional cameras, namely catadioptric cameras, is slowly emerging. These omnidirectional images will most probably deeply impact computer vision i ...

In this paper we present a generalization of geometric moments in scale-spaces derived from the general heat diffusion equation, with a particular interest for the

The thesis describes a great new sensor, the Panoptic Camera - a device made of 104 cameras patched on a half sphere. It describes and explains its fundamentals, the reasoning behind and its planned uses. It then covers the whole two-dimensional sparse interpolation problem by describing various methods, then used to provide impressive omnidirectional views.

The problem of finding the missing values of a matrix given a few of its entries, called matrix completion, has gathered a lot of attention in the recent years. Al- though the problem under the standard low rank assumption is NP-hard, Cande`s and Recht sho ...

Under resource constraints, LLMs are usually fine- tuned with additional knowledge using Parameter Efficient Fine-Tuning (PEFT), using Low-Rank Adaptation (LoRA) modules. In fact, LoRA injects a new set of small trainable matrices to adapt an LLM to a new ...

Les méthodes de localisation de sources acoustiques à l'aide de réseaux de microphones se limitent généralement à l'étude de sources à bande étroite situées en champ lointain. Le travail présenté a pour objectif de réaliser conjointement la localisation et ...

We propose a variant of Orthogonal Matching Pursuit (OMP), called LoCOMP, for scalable sparse signal approximation. The algorithm is designed for shift- invariant signal dictionaries with localized atoms, such as time-frequency dictionaries, and achieves a ...

We consider the probe of astrophysical signals through radio interferometers with small field of view and baselines with non-negligible and constant component in the pointing direction. In this context, the visibilities measured essentially identify with a ...

This paper discusses an improved pyramid for spatially scalable video coding. We introduce additional update steps in the analysis and the synthesis of the Laplacian pyramid. Our pyramid is able to control efficiently the quantization noise energy in the r ...

We propose and assess the performance of new imaging techniques for radio interferometry that rely on the versatility of the compressed sensing framework to account for prior information on the signals. The present manuscript represents a summary of recent ...

A novel hardware implementation of an omnidirectional image sensor is presented which is capable of acquiring and processing 3D image sequences in real time. The system consists of a hemispherical arrangement of a large number of CMOS imagers, connecting t ...

Inspired by the recently proposed Magnetic Resonance Fin- gerprinting technique, we develop a principled compressed sensing framework for quantitative MRI. The three key com- ponents are: a random pulse excitation sequence following the MRF technique; a ra ...

We present a general framework and an efficient algorithm for tracking relevant video structures. The structures to be tracked are implicitly defined by a Matching Pursuit procedure that extracts and ranks the most important image contours. Based on the ra ...

Pierre Vandergheynst

Chattez avec Graph Search

Steerable wavelet analysis of CMB structures alignment

Minimiseurs Globaux du Modele des Contours Actifs

Spread spectrum for interferometric and magnetic resonance imaging

Wavelet domain Bayesian denoising of string signal in the cosmic microwave background

Source Localization on Graphs via l1 Recovery and Spectral Graph Theory

Scale-space analysis and active contours for omnidirectional images

Geometric Moments in Scale-Spaces

The Panoptic Camera - Plenoptic interpolation in an omnidirectional polydioptric camera

Matrix Completion on Graphs

Beyond fine-tuning: LoRA modules boost near-OOD detection and LLM security

Localisation et identification spectrale conjointe de sources large bande par parcimonie groupée

A low complexity orthogonal matching pursuit for sparse signal approximation with shift-invariant dictionaries

Spread spectrum for imaging techniques in radio interferometry

Mapping resting-state dynamics on spatio-temporal graphs: a combined functional and diffusion MRI approach

An Improved Pyramid for Spatially Scalable Video Coding

Compressed sensing for radio interferometry: prior-enhanced Basis Pursuit imaging techniques

Hardware Implementation of an Omnidirectional Camera with Real-Time 3D Imaging Capability

Compressed Quantitative MRI: Bloch Response Recovery through iterated projection

Tracking Atoms with Particles for Audio-visual Source Localization

Interpreting and comparing neural activity across systems by geometric deep learning