The effects of amplitude-spectrum statistics on foveal and peripheral discrimination of changes in natural images, and a multi-resolution model
Parraga, Carlos Alejandro (University of Bristol. Department of Experimental Psychology)
Troscianko, Tom (University of Bristol. Department of Experimental Psychology)
Tolhurst, D.J. (University of Cambridge. Department of Physiology)

Date:	2005
Abstract:	Psychophysical thresholds were measured for discriminating small changes in spatial features of naturalistic scenes (morph sequences), for foveal and peripheral vision, and under M-scaling. Sensitivity was greatest for scenes with near natural Fourier amplitude slope, perhaps implying that human vision is optimised for natural scene statistics. A low-level model calculated differences in local contrast between pairs of images within a few spatial frequency channels with bandwidth like neurons in V1. The model was "customised" to each observer's contrast sensitivity function for sinusoidal gratings, and it could replicate the "U-shaped" relationships between discrimination threshold and spectral slope, and many differences between picture sets and observers. A single-channel model and an ideal-observer analysis both failed to capture the U-shape.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Natural scenes ; Contrast ; Optimisation ; Cortex model ; M-scaling ; Ideal observer
Published in:	Vision Research, Vol. 45, Issue 25-26 (November 2005) , p. 3145-3168, ISSN 1878-5646

DOI: 10.1016/j.visres.2005.08.006

Postprint 52 p, 1.0 MB

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