Publications associées à An objective method for determining principal time scales of coherent eddy structures using orthonormal wavelets

Optimally Localized Wavelets and Smoothing Kernels

It is well-known that the Gaussian functions and, more generally, their modulations-translations (the Gabor functions) have the unique property of being optimally localized in space and frequency in the sense of Heisenberg's uncertainty principle. In this ...

EPFL2011

Time-scale joint representation of DNS and LES numerical data

Michel Deville, Emmanuel Leriche, Roland Bouffanais

A spectral analysis and a multiscale study are performed on the numerical data obtained from direct numerical simulation and large-eddy simulation of the turbulent flow in a cubical lid-driven cavity. The analyzed data or signals are picked at three specif ...

2011

A Time-Domain Wavelet-Based Approach for Fluorescence Diffuse Optical Tomography

Michaël Unser, Chandra Sekhar Seelamantula

Purpose: In the context of fluorescence diffuse optical tomography, determining the optimal way to exploit the time-resolved information has been receiving much attention and different features of the time-resolved signals have been introduced. In this art ...

AAPM2010

Multiresolution Monogenic Signal Analysis Using the Riesz-Laplace Wavelet Transform

Michaël Unser, Dimitri Nestor Alice Van De Ville, Daniel Sage

The monogenic signal is the natural 2-D counterpart of the 1-D analytic signal. We propose to transpose the concept to the wavelet domain by considering a complexified version of the Riesz transform which has the remarkable property of mapping a real-value ...

Institute of Electrical and Electronics Engineers2009

The Pairing of a Wavelet Basis With a Mildly Redundant Analysis via Subband Regression

Michaël Unser, Dimitri Nestor Alice Van De Ville

A distinction is usually made between wavelet bases and wavelet frames. The former are associated with a one-to-one representation of signals, which is somewhat constrained but most efficient computationally. The latter are over-complete, but they offer ad ...

Institute of Electrical and Electronics Engineers2008

Continuous Wavelet Transform on the Hyperboloid

Pierre Vandergheynst, Iva Bogdanova Vandergheynst

In this paper we build a Continuous Wavelet Transform (CWT) on the upper sheet of the 2-hyperboloid

H_+^2

. First, we define a class of suitable dilations on the hyperboloid through conic projection. Then, incorporating hyperbolic motions belonging to $SO ...

2007

A New Family of Rotation-Covariant Wavelets on the Hexagonal Lattice

Dimitri Nestor Alice Van De Ville

We present multiresolution spaces of complex rotation-covariant functions, deployed on the 2-D hexagonal lattice. The designed wavelets, which are complex-valued, provide an important phase information for image analysis, which is missing in the discrete w ...

SPIE2007

Which Wavelet Bases Are the Best for Image Denoising?

Michaël Unser, Thierry Blu, Florian Luisier

We use a comprehensive set of non-redundant orthogonal wavelet transforms and apply a denoising method called SUREshrink in each individual wavelet subband to denoise images corrupted by additive Gaussian white noise. We show that, for various images and a ...

SPIE2005

Semi-Orthogonal Wavelets That Behave like Fractional Differentiators

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

The approximate behavior of wavelets as differential operators is often considered as one of their most fundamental properties. In this paper, we investigate how we can further improve on the wavelet's behavior as differentiator. In particular, we propose ...

SPIE2005

Wavelets on the 2-Hyperboloid

Pierre Vandergheynst, Iva Bogdanova Vandergheynst

We build wavelets on the 2-Hyperboloid. First, we define dilations on the hyperboloid through conic projection. Then, incorporating hyperbolic motions belonging to

SO_0(1,2)

, we define a family of hyperbolic wavelets. The continuous wavelet transform (CW ...

2004

An objective method for determining principal time scales of coherent eddy structures using orthonormal wavelets

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Optimally Localized Wavelets and Smoothing Kernels

Time-scale joint representation of DNS and LES numerical data

A Time-Domain Wavelet-Based Approach for Fluorescence Diffuse Optical Tomography

Multiresolution Monogenic Signal Analysis Using the Riesz-Laplace Wavelet Transform

The Pairing of a Wavelet Basis With a Mildly Redundant Analysis via Subband Regression

Continuous Wavelet Transform on the Hyperboloid

A New Family of Rotation-Covariant Wavelets on the Hexagonal Lattice

Which Wavelet Bases Are the Best for Image Denoising?

Semi-Orthogonal Wavelets That Behave like Fractional Differentiators

Wavelets on the 2-Hyperboloid

Optimally Localized Wavelets and Smoothing Kernels

Multiresolution Monogenic Signal Analysis Using the Riesz-Laplace Wavelet Transform

Continuous Wavelet Transform on the Hyperboloid

Time-scale joint representation of DNS and LES numerical data

A Time-Domain Wavelet-Based Approach for Fluorescence Diffuse Optical Tomography

A New Family of Rotation-Covariant Wavelets on the Hexagonal Lattice

Which Wavelet Bases Are the Best for Image Denoising?

Wavelets on the 2-Hyperboloid

The Pairing of a Wavelet Basis With a Mildly Redundant Analysis via Subband Regression

Semi-Orthogonal Wavelets That Behave like Fractional Differentiators