2018/01/17 by H. M. de Oliveira, de Oliveira, H. M., Renato J. Cintra +3
Computer Science · Mathematics · #Image and Signal Denoising Methods #Mathematical Analysis and Transform Methods #Advanced Data Compression Techniques
paper · pdf · doi:10.48550/arxiv.1801.05859
This paper presents a wavelet representation using baseband signals, by exploiting Kotel'nikov results. Details of how to obtain the processes of envelope and phase at low frequency are shown. The archetypal interpretation of wavelets as an analysis with a filter bank of constant quality factor is revisited on these bases. It is shown that if the wavelet spectral support is limited into the band [fm,fM], then an orthogonal analysis is guaranteed provided that fM ≤ 3fm, a quite simple result, but that invokes some parallel with the Nyquist rate. Nevertheless, in cases of orthogonal wavelets whose spectrum does not verify this condition, it is shown how to construct an "equivalent" filter bank with no spectral overlapping.