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Chromaticity of unique white in object mode
Optics Express
|November 18, 2014
Summary
Investigating unique white perception under dark adaptation revealed significant observer variation. Average unique white shifted towards colder colors at lower luminances, with a model developed to predict perceived neutrality.
Area of Science:
- Visual perception
- Color science
- Psychophysics
Background:
- Understanding 'unique white' is crucial for color appearance modeling.
- Previous research has explored white point perception, but less is known about its behavior under dark adaptation across varying luminances.
Purpose of the Study:
- To investigate the chromaticity of unique white under dark adaptation across different luminance levels.
- To compare unique white perception using setting and rating methods.
- To develop a predictive model for perceived white neutrality.
Main Methods:
- Two experimental methods were employed: unique white setting and rating.
- Chromaticity was assessed at three luminance levels: 200, 1000, and 2000 cd/m².
- Observer variation and shifts in unique white were analyzed.
Main Results:
- Both methods showed good agreement, but with considerable observer variation.
- A shift towards colder correlated color temperatures was observed for average unique white as luminance decreased.
- Unique white occupies a region in color space, generally below the blackbody locus around 6000 K.
Conclusions:
- Observer variability significantly impacts unique white perception under dark adaptation.
- Luminance influences the perceived unique white, shifting it towards cooler tones at lower levels.
- A Gaussian model effectively predicts the neutrality of object stimuli under dark conditions.
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