Recherche

Afficher tous les résultats pour

Accueil

Personne

Michaël Unser

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (516)

Variational B-Spline Level-Set: A Linear Filtering Approach for Fast Deformable Model Evolution

Philippe Thévenaz, Michaël Unser, Olivier Bernard

In the field of image segmentation, most level-set-based active-contour approaches take advantage of a discrete representation of the associated implicit function. We present in this paper a different formulation where the implicit function is modeled as a ...

IEEE2009

Laser Doppler imaging for intraoperative human brain mapping

Marcel Leutenegger, Michaël Unser, Theo Lasser, Dimitri Nestor Alice Van De Ville, Rainer Leitgeb, Erica Martin-Williams

The identification and accurate location of centers of brain activity are vital both in neuro-surgery and brain research. This study aimed to provide a non-invasive, non-contact, accurate, rapid and user-friendly means of producing functional images intrao ...

Elsevier2009

Laplace-Gradient Wavelet Pyramid and Multiscale Tensor Structures Applied on High-Resolution DEMs

François Golay, Michaël Unser, Michaël Kalbermatten, Stéphane Joost, Dimitri Nestor Alice Van De Ville

University of Zürich2009

A Fast Multilevel Algorithm for Wavelet-Regularized Image Restoration

Michaël Unser, Cédric René Jean Vonesch

We present a multilevel extension of the popular "thresholded Landweber" algorithm for wavelet-regularized image restoration that yields an order of magnitude speed improvement over the standard fixed-scale implementation. The method is generic and targete ...

IEEE2009

Self-Similar Random Vector Fields and Their Wavelet Analysis

Michaël Unser, Pouya Dehghani Tafti

This paper is concerned with the mathematical characterization and wavelet analysis of self-similar random vector fields. The study consists of two main parts: the construction of random vector models on the basis of their invariance under coordinate trans ...

SPIE2009

Halton Sampling for Image Registration Based on Mutual Information

Philippe Thévenaz, Michaël Unser, Michel Bierlaire

Mutual information is a widely used similarity measure for aligning multimodal medical images. At its core it relies on the computation of a discrete joint histogram, which itself requires image samples for its estimation. In this paper we study the influe ...

Sampling Publishing2008

The Marr Wavelet Pyramid

Michaël Unser, Dimitri Nestor Alice Van De Ville

We introduce a new semi-orthogonal complex wavelet basis of L-2(R-2). The basis functions are associated to the complex gradient-Laplace operator, which plays a central role in image processing. We define analytically a single-generator wavelet that is shi ...

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

An accurate PSF model with few parameters for axially shift-variant deconvolution

Michaël Unser, François Aguet, Dimitri Nestor Alice Van De Ville

Accurate knowledge of an imaging system's point spread function (PSF) is crucial for successful deconvolution. For fluorescence microscopy, PSF estimations based on either theoretical models or experimental measurements are available. However, due to the a ...

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

Multiframe SURE-LET denoising of timelapse fluorescence microscopy images

Michaël Unser, Thierry Blu, Florian Luisier, Saskia Joëlle Delpretti Anex, Sathish Ramani

Due to the random nature of photon emission and the various internal noise sources of the detectors, real timelapse fluorescence microscopy images are usually modeled as the sum of a Poisson process plus some Gaussian white noise. In this paper, we propose ...

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

Shift-Invariant Spaces from Rotation-Covariant Functions

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

We consider shift-invariant multiresolution spaces generated by rotation-covariant functions ρ in

\mathbb{R}^{ 2 }

. To construct corresponding scaling and wavelet functions, ρ has to be localized with an appropriate multiplier, such that the localized ...

Elsevier2008

A spline-based forward model for Optical Diffuse Tomography

Michaël Unser, Jean-Charles Baritaux

Reconstruction algorithms for Optical Diffuse Tomography (ODT) rely heavily on fast and accurate forward models. Arbitrary geometries and boundary conditions need to be handled rigorously since they are the only input to the inverse problem. From this pers ...

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

Performance analysis of the cepstral technique for frequency-domain optical-coherence tomography

Michaël Unser

Recently, we proposed a noniterative cepstral technique for exact signal recovery in frequency-domain optical-coherence tomography. In this paper, we address the influence of measurement noise on the performance of the method. We derive analytical expressi ...

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

False Discovery Rate for Wavelet-Based Statistical Parametric Mapping

Michaël Unser, Dimitri Nestor Alice Van De Ville

Model-based statistical analysis of functional magnetic resonance imaging (fMRI) data relies on the general linear model and statistical hypothesis testing. Due to the large number of intracranial voxels, it is important to deal with the multiple compariso ...

IEEE2008

Elastic Image Registration of 2-D Gels for Differential and Repeatability Studies

Philippe Thévenaz, Michaël Unser

One of the main applications of electrophoretic 2-D gels is the analysis of differential responses between different conditions. For this reason, specific spots are present in one of the images, but not in the other. In some other occasions, the same exper ...

Wiley InterScience2008

A Generalized Sampling Method for Finite-Rate-of-Innovation-Signal Reconstruction

Michaël Unser, Chandra Sekhar Seelamantula

The problem of sampling signals that are not admisible within the classical Shannon framework has received much attention in the recent past. Typically, these signals have a parametric representation with a finite number of degrees of freedom per time unit ...

IEEE Institute of Electrical and Electronics Engineers2008

Deconvolution of 3D fluorescence micrographs with automatic risk minimization

Michaël Unser, Cédric René Jean Vonesch, Sathish Ramani

We investigate the problem of automatic tuning of a deconvolution algorithm for three-dimensional (3D) fluorescence microscopy; specifically, the selection of the regularization parameter lambda. For this, we consider a realistic noise model for data obtai ...

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

Nonideal Sampling and Regularization Theory

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

Shannon's sampling theory and its variants provide effective solutions to the problem of reconstructing a signal from its samples in some “shift-invariant” space, which may or may not be bandlimited. In this paper, we present some further justification for ...

IEEE2008

Fast Adaptive Elliptical Filtering Using Box Splines

Michaël Unser, Kunal Narayan Chaudhury

We demonstrate that it is possible to filter an image with an elliptic window of varying size, elongation and orientation with a fixed computational cost per pixel. Our method involves the application of a suitable global pre-integrator followed by a point ...

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

Complex Wavelet Bases, Steerability, and the Marr-Like Pyramid

Michaël Unser, Dimitri Nestor Alice Van De Ville

Our aim in this paper is to tighten the link between wavelets, some classical image-processing operators, and David Marr's theory of early vision. The cornerstone of our approach is a new complex wavelet basis that behaves like a smoothed version of the Gr ...

Institute of Electrical and Electronics Engineers2008

Recursive Risk Estimation For Non-Linear Image Deconvolution With A Wavelet-Domain Sparsity Constraint

Michaël Unser, Cédric René Jean Vonesch, Sathish Ramani

We propose a recursive data-driven risk-estimation method for non-linear iterative deconvolution. Our two main contributions are 1) a solution-domain risk-estimation approach that is applicable to non-linear restoration algorithms for ill-conditioned inver ...

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

Page 21 sur 26