Luminance-color correlation is not used to estimate the color of the illumination

JJM Granzier*, E Brenner, FW Cornelissen, JBJ Smeets

*Corresponding author for this work

    Research output: Contribution to journalArticleAcademicpeer-review

    20 Citations (Scopus)
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    Abstract

    Humans can identify the colors of objects fairly consistently, despite considerable variations in the spectral composition of the illumination. It has been suggested that the correlation between luminance and color within a scene helps to disentangle the influences of illumination and reflectance, because the surfaces that reflect the light of the illuminant well will normally be bright. Because the reliability of the luminance-color correlation as an indicator of the chromaticity of the illuminant depends on the number of surfaces that are considered, we expected the correlation to be determined across large parts of the scene. To examine whether this is so, we compared different scenes with matched luminance and chromaticity, but in which the correlation between luminance and chromaticity was manipulated locally. Our results confirm that there is a bias in perceived color away from the chromaticity of bright surfaces. However, the results show that only the correlation within about 1degrees of the target is relevant. Thus, it is unlikely that the visual system uses the correlation between luminance and color to explicitly determine the chromaticity of the illuminant. Instead, this correlation is presumably implicitly considered in the way that the color contrast at borders is determined.

    Original languageEnglish
    Pages (from-to)20-27
    Number of pages8
    JournalJOURNAL OF VISION
    Volume5
    Issue number1
    DOIs
    Publication statusPublished - 2005

    Keywords

    • color vision
    • chromatic induction
    • color constancy
    • cone-excitation ratios
    • CHROMATIC INDUCTION
    • CONSTANCY

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