Tracking categorical surface colour across illuminant changes in natural scenes

Kinjiro Amano, David H. Foster

    Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

    Abstract

    How well can categorical colour perception be maintained in natural environments with varying illuminants? To address this question, a colour-naming experiment was performed with colour-monitor images of natural scenes simulated under two different daylights of correlated colour temperature 6500 K and 25000 K. Images were obtained from a set of hyperspectral data to enable the accurate control of illuminant and reflectance spectra. Each scene contained a spherical test surface whose digitally manipulated spectral reflectance coincided with that of a sample drawn randomly from approximately 430 Munsell reflectances grouped into eight colour categories, namely, red, green, blue, yellow, pink, purple, brown, and orange. Observers had to name the colour of the test surface in each image, presented for I s, by pressing one of nine computer keys corresponding to the eight categorical colour names and a neutral category. Focal colours were estimated from the peaks of the smoothed distributions of observers' naming responses in the C1E 1976 (u' v') chromaticity diagram. The effect of the illuminant change was quantified by a focal colour constancy index, with values 0 and 1 corresponding to no constancy and perfect constancy. Average levels of focal colour constancy were close to those from traditional measures of colour constancy, but with variation across categories and surface lightness. For blue and purple surfaces levels approached 0.9. For many surface colours, colour naming seems to be robust under Hluminant changes and may help to anchor non-categorical judgements of arbitrary surface colours in natural scenes.
    Original languageEnglish
    Title of host publication5th European Conference on Colour in Graphics, Imaging, and Vision and 12th International Symposium on Multispectral Colour Science 2010, CGIV 2010/MCS'10|Eur. Conf. Colour Graph., Imaging, Vis. Int. Symp. Multispectral Colour Sci., CGIV/MCS
    PublisherSociety for Imaging Science and Technology
    Pages289-292
    Number of pages3
    ISBN (Print)9781617388897
    Publication statusPublished - 2010
    Event5th European Conference on Colour in Graphics, Imaging, and Vision and 12th International Symposium on Multispectral Colour Science 2010, CGIV 2010/MCS'10 - Joensuu
    Duration: 1 Jul 2010 → …

    Conference

    Conference5th European Conference on Colour in Graphics, Imaging, and Vision and 12th International Symposium on Multispectral Colour Science 2010, CGIV 2010/MCS'10
    CityJoensuu
    Period1/07/10 → …

    Fingerprint

    Dive into the research topics of 'Tracking categorical surface colour across illuminant changes in natural scenes'. Together they form a unique fingerprint.

    Cite this