Publications de Thierry Blu | EPFL Graph Search

Efficient Multi-dimensional Diracs Estimation with Linear Sample Complexity

Martin Vetterli, Thierry Blu, Hanjie Pan

Estimating Diracs in continuous two or higher dimensions is a fundamental problem in imaging. Previous approaches extended one dimensional methods, like the ones based on finite rate of innovation (FRI) sampling, in a separable manner, e.g., along the hori ...

2018

LEAP: Looking beyond pixels with continuous-space EstimAtion of Point sources

Martin Vetterli, Paul Hurley, Thierry Blu, Hanjie Pan, Matthieu Martin Jean-André Simeoni

Context. Two main classes of imaging algorithms have emerged in radio interferometry: the CLEAN algorithm and its multiple variants, and compressed-sensing inspired methods. They are both discrete in nature, and estimate source locations and intensities on ...

2017

Towards Generalized FRI Sampling with an Application to Source Resolution in Radioastronomy

Martin Vetterli, Thierry Blu, Hanjie Pan

It is a classic problem to estimate continuous-time sparse signals, like point sources in a direction-of-arrival problem, or pulses in a time-of-flight measurement. The earliest occurrence is the estimation of sinusoids in time series using Prony's method. ...

Institute of Electrical and Electronics Engineers2017

Reconstruction of Finite Rate of Innovation Signals with Model-Fitting Approach

Thierry Blu, Dimitri Nestor Alice Van De Ville, Zafer Dogan

Finite rate of innovation (FRI) is a recent framework for sampling and reconstruction of a large class of parametric signals that are characterized by finite number of innovations (parameters) per unit interval. In the absence of noise, exact recovery of F ...

Institute of Electrical and Electronics Engineers2015

Annihilation-driven Localised Image Edge Models

Martin Vetterli, Thierry Blu, Hanjie Pan

We propose a novel edge detection algorithm with sub-pixel accuracy based on annihilation of signals with finite rate of innovation. We show that the Fourier domain annihilation equations can be interpreted as spatial domain multiplications. From this new ...

IEEE2015

Application of a New Sensing Principle for Photoacoustic Imaging of Point Absorbers

Thierry Blu, Dimitri Nestor Alice Van De Ville, Ivana Jovanovic, Zafer Dogan

Photoacoustic tomography (PAT) is a hybrid imaging method, which combines ultrasonic and optical imaging modalities, in order to overcome their respective weaknesses and to combine their strengths. It is based on the reconstruction of optical absorption pr ...

Spie-Int Soc Optical Engineering2013

Eigensensing And Deconvolution For The Reconstruction Of Heat Absorption Profiles From Photoacoustic Tomography Data

Thierry Blu, Dimitri Nestor Alice Van De Ville, Zafer Dogan

Photoacoustic tomography (PAT) is a relatively recent imaging modality that is promising for breast cancer detection and breast screening. It combines the high intrinsic contrast of optical radiation with acoustic imaging at submillimeter spatial resolutio ...

Ieee2013

Analytic Sensing For Multi-Layer Spherical Models With Application To EEG Source Imaging

Thierry Blu, Dimitri Nestor Alice Van De Ville, Djano Kandaswamy

Source imaging maps back boundary measurements to underlying generators within the domain; e. g., retrieving the parameters of the generating dipoles from electrical potential measurements on the scalp such as in electroencephalography (EEG). Fitting such ...

Amer Inst Mathematical Sciences2013

3D Reconstruction Of Wave-Propagated Point Sources From Boundary Measurements Using Joint Sparsity And Finite Rate Of Innovation

Thierry Blu, Dimitri Nestor Alice Van De Ville, Ivana Jovanovic, Zafer Dogan

Reconstruction of point sources from boundary measurements is a challenging problem in many applications. Recently, we proposed a new sensing and non-iterative reconstruction scheme for systems governed by the three-dimensional wave equation. The points so ...

IEEE Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2012

Image Denoising in Mixed Poisson-Gaussian Noise

Michaël Unser, Thierry Blu, Florian Luisier

We propose a general methodology (PURE-LET) to design and optimize a wide class of transform-domain thresholding algorithms for denoising images corrupted by mixed Poisson-Gaussian noise. We express the denoising process as a linear expansion of thresholds ...

Institute of Electrical and Electronics Engineers2011

Analytical Footprints: Compact Representation of Elementary Singularities in Wavelet Bases

Michaël Unser, Thierry Blu, Dimitri Nestor Alice Van De Ville

We introduce a family of elementary singularities that are point-Holder alpha-regular. These singularities are self-similar and are the Green functions of fractional derivative operators; i.e., by suitable fractional differentiation, one retrieves a Dirac ...

Institute of Electrical and Electronics Engineers2010

Fast Interscale Wavelet Denoising of Poisson-Corrupted Images

Michaël Unser, Thierry Blu, Florian Luisier, Cédric René Jean Vonesch

We present a fast algorithm for image restoration in the presence of Poisson noise. Our approach is based on (1) the minimization of an unbiased estimate of the MSE for Poisson noise, (2) a linear parametrization of the denoising process and (3) the preser ...

Elsevier2010

Low-Bond Axisymmetric Drop Shape Analysis for Surface Tension and Contact Angle Measurements of Sessile Drops

Michaël Unser, Daniel Sage, Thierry Blu, Michael Müller

A new method based on the Young-Laplace equation for measuring contact angles and surface tensions is presented. In this approach, a first-order perturbation technique helps to analytically solve the Young-Laplace equation according to photographic images ...

Elsevier2010

SURE-LET for Orthonormal Wavelet-Domain Video Denoising

Michaël Unser, Thierry Blu, Florian Luisier

We propose an efficient orthonormal wavelet-domain video denoising algorithm based on an appropriate integration of motion compensation into an adapted version of our recently devised Stein's unbiased risk estimator-linear expansion of thresholds (SURE-LET ...

IEEE2010

Undecimated Haar Thresholding For Poisson Intensity Estimation

Michaël Unser, Thierry Blu, Florian Luisier

We propose a novel algorithm for denoising Poisson-corrupted images, that performs a signal-adaptive thresholding of the undecimated Haar wavelet coefficients. A Poisson's unbiased MSE estimate is devised and adapted to arbitrary transform-domain pointwise ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2010

A bulk modulus dependent linear model for acoustical imaging

Michaël Unser, Thierry Blu

Modeling the acoustical process of soft biological tissue imaging and understanding the consequences of the approximations required by. such modeling are key steps for accurately simulating ultrasonic scanning as well as estimating the scattering coefficie ...

ASA2009

On Sampling Lattices with Similarity Scaling Relationships

Thierry Blu, Dimitri Nestor Alice Van De Ville

We provide a method for constructing regular sampling lattices in arbitrary dimensions together with an integer dilation matrix. Subsampling using this dilation matrix leads to a similarity-transformed version of the lattice with a chosen density reduction ...

LATP2009

Analytic Sensing: Noniterative Retrieval Of Point Sources From Boundary Measurements

Thierry Blu, Dimitri Nestor Alice Van De Ville, Djano Kandaswamy

We consider the problem of locating point sources in the planar domain from overdetermined boundary measurements of solutions of Poisson's equation. In this paper, we propose a novel technique, termed "analytic sensing," which combines the application of G ...

SIAM2009

Fast Haar-Wavelet Denoising Of Multidimensional Fluorescence Microscopy Data

Michaël Unser, Thierry Blu, Florian Luisier, Cédric René Jean Vonesch

We propose a novel denoising algorithm to reduce the Poisson noise that is typically dominant in fluorescence microscopy data. To process large datasets at a low computational cost, we use the unnormalized Haar wavelet transform. Thanks to some of its appe ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2009

EEG source localization by multi-planar analytic sensing

Thierry Blu, Dimitri Nestor Alice Van De Ville, Djano Kandaswamy, Clotaire Michel

Source localization from EEG surface measurements is an important problem in neuro-imaging. We propose a new mathematical framework to estimate the parameters of a multidipole source model. To that aim, we perform 2-D analytic sensing in multiple planes. T ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2008