Oversampled optical subband decomposition

A semidiscrete wavelet transform is realized using optical subband decompos ition through which a signal is decomposed into translation-invariant subba nds. Correspondingly, the translation parameter within each subband is disc retized using a CCD array. Since the sampling lattice of a CCD array is fix ed, the subband signals can be oversampled, critically sampled, or undersam pled. The oversampled subband signals contribute to reduced translation dep endence and improved robustness. In the presence of additive noise, we show that oversampling reduces the reconstruction error. (C) 2000 Society of Ph oto-Optical instrumentation Engineers. [S0091-3286(00)00709-1].