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Lookup NU author(s): Professor Anya Hurlbert
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Previous studies suggest that to achieve colour constancy, the human visual systemmakes use ofmultiple cues, including a priori assumptions about the illumination (“daylight priors”). Specular highlights have been proposed to aid constancy, but the evi dence for their usefulness is mixed. Here, we used a novel cue-combination approachto test whether the presence of specular highlights or the validity of a daylight prior improves illumination chromaticity estimates, inferred from achromatic settings, to determine whether and under which conditions either cue contributes to colour constancy.Observers made achromatic settings within three-dimensional rendered scenes containing matte or glossy shapes, illuminated by either daylight or non-daylight illuminations. We assessed both the variability of these settings and their accuracy, in terms of the standard colour constancy index (CCI). When a spectrally uniform background was present, neither CCIs nor variability improved with specular highlights or daylight illuminants (Experiment 1). When a Mondrian background was introduced, CCIs decreased overall, but were higher for scenes containing glossy, as opposed to matte,shapes (Experiments 2 and 3). There was no overall reduction in variability of settings,and no benefit for scenes illuminated by daylights. Taken together, these results sugest that the human visual system indeed uses specular highlights to improve colour constancy, but only when other cues, such as from the local surround, are weakened.
Author(s): Wedge-Roberts R, Aston S, Beierholm U, Kentridge R, Hurlbert A, Nardini M, Olkkonen M
Publication type: Article
Publication status: Published
Journal: Journal of Vision
Year: 2020
Volume: 20
Issue: 12
Online publication date: 10/11/2020
Acceptance date: 07/09/2020
Date deposited: 08/01/2021
ISSN (electronic): 1534-7362
Publisher: Association for Research in Vision and Ophthalmology
URL: https://doi.org/10.1167/jov.20.12.4
DOI: 10.1167/jov.20.12.4
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