Wavelet-based bootstrapping of spatial patterns on a finite lattice

  • Authors:
  • Brandon Whitcher

  • Affiliations:
  • Translational Medicine & Technology, GlaxoSmithKline, Greenford Road, Greenford UB6 0HE, United Kingdom

  • Venue:
  • Computational Statistics & Data Analysis
  • Year:
  • 2006

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Abstract

A semi-parametric bootstrap procedure is proposed for two-dimensional spatial processes on a finite lattice (images). Discrete wavelet transforms are used to produce coefficients that are approximately uncorrelated in space. For illustration, realizations of spatial processes from the Matern class of spectral density functions are analyzed. The goal is to obtain bootstrap realizations by applying the nai@?ve bootstrap to the approximately uncorrelated wavelet coefficients. The methodology is shown to be effective at reproducing moderate levels of spatial covariance on several simulated data sets as well as images taken from a functional magnetic resonance imaging (fMRI) experiment. An application to testing functional connectivity in fMRI is also presented.