Color, Depth, and Size

100 Color and Luminance Constancy

Learning Objectives

Be able to explain the main three things that contribute to our ability to experience an object as being the same color.

Understand the differences/similarities between color and lightness constancy.

There are three main aspects of vision that allow the consistent perception of color in objects independent of illumination:

  1. Chromatic adaptation: when the light source contains a disproportionate amount of light in one section of the spectrum, the responses of the relevant photoreceptors are suppressed, shifting our perception away from the dominant wavelength.
  2. Local context: we compare all the colors in a scene to normalize our perception. This process takes place at a conscious and unconscious level.
  3. Prior knowledge: certain objects characterized by a distinct color will be perceived as this color despite differential illumination.

Light constancy concerns the relative reflectance of an object independent of illumination. Color constancy deals with the perception of color independent of illumination.

 

Fig.10.5.1. Color Consistency. Image shows how squares with the same luminance appear to be different colors due to environmental shadows (Credit: Jarod Davis. Provided by: University of Minnesota. License: CC-BY SA 4.0)

To learn more, take a look at this video about color and light constancy with great examples!

CC LICENSED CONTENT, SHARED PREVIOUSLY
Cheryl Olman PSY 3031 Detailed Outline
Provided by: University of Minnesota
Download for free at http://vision.psych.umn.edu/users/caolman/courses/PSY3031/
License of original source: CC Attribution 4.0
Adapted by: Trevor Graham

License

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Introduction to Sensation and Perception by Students of PSY 3031 and Edited by Dr. Cheryl Olman is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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