Concept

Bessel function

Related publications (144)

Image compression with learnt tree-structured dictionaries

Pierre Vandergheynst, Gianluca Monaci, Philippe Jost

In the present paper we propose a new framework for the construction of meaningful dictionaries for sparse representation of signals. The dictionary approach to coding and compression proves very attractive since decomposing a signal over a redundant set o ...

2004

Existence, uniqueness and regularity of solutions for a thermomechanical model of shape memory alloys

This thesis is devoted to the study of a thermomechanical model describing the macroscopic behavior of shape memory alloys. The analyzed model takes into account the non-isothermal character of the phase transition, as well as the existence of the intrinsi ...

EPFL2004

A Variational Model for Object Segmentation Using Boundary Information, Statistical Shape Prior and the Mumford-Shah Functional

Jean-Philippe Thiran, Pierre Vandergheynst, Xavier Bresson

In this paper, we propose a variational model to segment an object belonging to a given scale space using the active contour method, a geometric shape prior and the Mumford-Shah functional. We define an energy functional composed by three complementary ter ...

2004

Solvation dynamics at water-ZrO2 interfaces

Majed Chergui, Jacques-Edouard Moser, Frank van Mourik, Erwin Portuondo Campa

The dye coumarin 343 (C343) adsorbed on the surface of ZrO2 nanoparticles in aq. solns. was used to study the solvation dynamics close to these surfaces. The time-resolved Stokes shift was measured by femtosecond frequency-resolved upconversion. The absorp ...

2004

A Complete Family of Scaling Functions: The (α, τ)-Fractional Splines

Michaël Unser, Thierry Blu

We describe a new family of scaling functions, the (α, τ)-fractional splines, which generate valid multiresolution analyses. These functions are characterized by two real parameters: α, which controls the width of the scaling functions; and τ, which specif ...

IEEE2003

Folded shift multiplexing

Demetri Psaltis, Wei Liu

Shift multiplexing is a holographic recording method that uses a spherical reference wave. We extend the principle to a thin slab of holographic material that acts as a waveguide. Total internal reflection folds the reference spherical beam in one dimensio ...

2003

The PROSITE database, its status in 2002

Philipp Bucher, Amos Bairoch

PROSITE [Bairoch and Bucher (1994) Nucleic Acids Res., 22, 3583-3589; Hofmann et al. (1999) Nucleic Acids Res., 27, 215-219] is a method of identifying the functions of uncharacterized proteins translated from genomic or cDNA sequences. The PROSITE databas ...

2002

Wavelets, Fractals, and Radial Basis Functions

Michaël Unser, Thierry Blu

Wavelets and radial basis functions (RBFs) lead to two distinct ways of representing signals in terms of shifted basis functions. RBFs, unlike wavelets, are nonlocal and do not involve any scaling, which makes them applicable to nonuniform grids. Despite t ...

IEEE2002

Wavelets on the sphere : Implementation and approximations

Pierre Vandergheynst, Laurent Jacques

We continue the analysis of the continuous wavelet transform on the 2-sphere, introduced in a previous paper. After a brief review of the transform, we define and discuss the notion of directional spherical wavelet, i.e., wavelets on the sphere that are se ...

2002

Redundancy in Non-Orthogonal Transforms

Pascal Frossard, Pierre Vandergheynst

Compression efficiency is mainly driven by redundancy of the overcomplete set of functions chosen for the signal decomposition. In Matching Pursuit algorithms for example, the redundancy of the dictionary influences the convergence of the residual energy. ...

EUSIPCO2001

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