Localisation fréquentielle des paquets d'ondelettes.

Título original	Localisation fréquentielle des paquets d'ondelettes.
Título inglés	Frequency localization of wavelet packets.
Título español	Localización frecuencial de los paquetes de ondículas.
Autor/es	Séré, Eric
Organización	CEREMADE Univ. Paris IX-Dauphine, París, Francia
Revista	0213-2230
Publicación	1995, 11 (2): 334-354, 7 Ref.
Tipo de documento	articulo
Idioma	Francés
Resumen inglés	Orthonormal bases of wavelet packets constitute a powerful tool in signal compression. It has been proved by Koifman, Meyer and Wickerhauser that many wavelet packets wn suffer a lack of frequency localization. Using the L1-norm of the Fourier transform ^wn as localization criterion, they showed that the average 2-jΣn=02j-1 ||^wn||L1 blows up as j goes to infinity. A natural problem is then to know which values of n create this blow-up in average. The present work gives an answer to this question, thanks to sharp estimates on ||^wn||L1 which depend on the dyadic expension of n, for several types of filters. Let us point out that the value of ||^wn||L1 is a weak localization criterion, which can only lead to a lower estimate on the variance of ^wn.
Clasificación UNESCO	120220
Palabras clave español	Tratamiento de señales ; Función armónica ; Algoritmos de filtro ; Bases ortonormales ; Paquetes ; Ondículas ; Filtro divisor frecuencias
Código MathReviews	MR1344896
Código Z-Math	Zbl 0829.42024
Acceso al artículo completo