[OPTICAL REVIEW Vol. 11, No. 4 (2004) 217-225]
© 2004 The Optical Society of Japan

Color Appearance Explained, Predicted and Confirmed by the Concept of Recognized Visual Space of Illumination

Mitsuo IKEDA*

Department of Photonics, Faculty of Science and Engineering, Ritsumeikan University, Nojihigashi, Kusatsu, Shiga 525-8577, Japan

(Received April 9, 2004; Accepted April 30, 2004)

Ten years have passed since we proposed a new concept called recognized visual space of illumination (RVSI). The central idea of the concept assumes that our brain first recognizes how a space is illuminated and then judges colors of anything seen in the space in relation to the RVSI constructed for the space. In another expression we say that the space is recognized first and the color perception next. In this paper some of our experiments that proved the appropriateness of the concept will be introduced. When a white paper was seen through a colored filter we could perceive the paper as white at the same instant we recognized a space through and beyond the filter. When an achromatic patch independent from the room illumination was observed under colored illumination its appearance immediately changed to that roughly opponent to the illumination color. When two gray patches of the same lightness were drawn in a picture of a white grating on a black background on a way that one appeared to locate on this side of the grating and the other in the other side, the former appeared brighter. These all confirmed the predictions based on the RVSI concept.

Key words: color appearance, apparent lightness, illumination, recognized visual space of illumination, color constancy, lightness constancy, adaptation, elementary color naming, color opponency

*E-mail address: mikeda@se.ritsumei.ac.jp