Wideband frequency excursions in computed AM-FM image models

Abstract

We examine two paradigms for computing multicomponent AM-FM image models. In channelized components analysis, estimates for one AM-FM component are extracted from each channel of a multiband filterbank. Tracked multi-component analysis represents an image using fewer components by tracking the estimated modulating functions of each component across the filter bank channels. While both approaches work well for synthetic images, they have difficulty with natural images that contain phase discontinuities. We show that phase discontinuities lead to wideband frequency excursions that make the computation of AM-FM models difficult and can also severely degrade the quality of image reconstructions obtained from the models. We use postfilters to ameliorate the effects of the frequency excursions and compute AM-FM models for two natural images.