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 |