Wavelet deconvolution in a periodic setting

Autor: Gerard Kerkyacharian, Iain M. Johnstone, Dominique Picard, Marc Raimondo
Přispěvatelé: Laboratoire de Probabilités et Modèles Aléatoires (LPMA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Benassù, Serena
Jazyk: angličtina
Rok vydání: 2004
Předmět:
Zdroj: Journal of the Royal Statistical Society: Series B
Journal of the Royal Statistical Society: Series B, 2004, 66 n.3, pp.547-573
Journal of the Royal Statistical Society: Series B, Royal Statistical Society, 2004, 66 n.3, pp.547-573
ISSN: 1369-7412
1467-9868
Popis: In this paper, we present an inverse estimation procedure which combines Fourier analysis with wavelet expansion. In the periodic setting, our method can recover a blurred function observed in white noise. The blurring process is achieved through a convolution operator which can either be smooth (polynomial decay of the Fourier transform) or irregular (such as the convolution with a box-car). The proposal is non-linear and does not require any prior knowledge of the smoothness class; it enjoys fast computation and is spatially adaptive. This contrasts with more traditional ltering methods which demand a certain amount of regularisation and often fail to recover non-homogeneous functions. A ne tuning of our method is derived via asymptotic minimax theory which reveals some key dierences with the direct case of Donoho et al. (1995): (a) band-limited wavelet families have nice theoretical and computing features; (b) the high frequency cut o depends on the spectral characteristics of the convolution kernel; (c) thresholds are level dependent in a geometric fashion. We tested our method using simulated lidar data for underwater remote sensing. Both visual and numerical results show an improvement over existing methods. Finally, the theory behind our estimation paradigm gives a complete characterisation of the ’Maxiset’ of the method i.e. the set of functions where the method attains a near-optimal rate of convergence for a variety of L p loss functions.
Databáze: OpenAIRE