Modelling the power spectra of natural images: Statistics and information

Power spectra of an extensive set of natural images were analysed, Both the total power in a spectrum (corresponding to image contrast) and its dependence on spatial frequency vary considerably between images, and also within images when considered as functions of orientation, A series of probabilistic models for power spectra enabled calculating the information obtained from prior knowledge of parameters describing spectra, Most information is gained from contrast, 1/f(2) spatial frequency behaviour, and contrast as a function of orientation, Variations in spatial frequency behaviour are relatively unimportant. For oriented contrast, a bandwidth of 10-30 deg is sufficient to obtain most information. Copyright (C) 1996 Elsevier Science Ltd.