Color appearance of color chips under light‐emitting diode lamps

Abstract

Many kinds of research have been undertaken on color constancy under various illuminations; however, not many people have studied this domain in the context of vivid colored light. In this article, 23 color chips were assessed using the elementary color‐naming method under 13 RGB‐LED illuminations of six hues as red, yellow, green, cyan, blue, and magenta. A total of 100 subjects participated in the study and reported that color chips of cyan, yellow, and green light were not good as compared to the others. This article also proposes an elementary color‐naming method as an alternative way to study and calculate color constancy index using the two rooms technique as extending experiment booth to get the color appearance of the color chip without adapting to the colored illumination. Our results suggested individual color appearance performance for each colored light which yellow, cyan, and green are not recommended as shown by poor area ratio and color constancy index.

Color appearance of color chips under light‐emitting diodes lamps part II: Hue shift direction

“…In the previous report, 1 we found that the area perception between less vivid light conditions and the D65 light as the reference had a small difference that was shown by a high area ratio index, which ranged from 0 to 1 as no area perception compared to the reference area and having the exact amount of area perception same as the reference area, respectively. We also presented the perception color constancy index calculated based on the perceptual color space determined by the distance between the perception adapted to the illumination distance and the perception without adapting to the illumination distance.…”

“…Experimental booths: the left (A) shows the booth used in Experiment 1. The right (B) shows an example of the apparatus for Experiment 2, in which the booth was separated into the test room illuminated by various colored lights and the subject room illuminated by only white light 1 …”

“…This article was a continued analysis of the previous study 1 . We used the results obtained from both experiments with only vivid colored illuminations in this article.…”

“…Chromatic adaptation is a human ability that allows the visual system to adjust color perception by cancelling color illumination to perceive the original surface object. 1 How the human visual system understands colored illumination has become a big question, since the light reflected from an object is already mixed and composed between the spectral power distribution of the light and spectral reflection distribution of the object. There have been many studies on this topic, such as the geometry of color distributions ,2 grey-world hypothesis, 3 and so on.…”

“…In our previous research 1 on the color appearance of color chips under light-emitting diodes lamps, we proposed elementary color naming, which is similar to hue and saturation scaling, 16 to be an alternative method for studying color appearance and constancy. We found that color constancy was different depending on colored illumination conditions, similar to previous research .17 ,18 The elementary color-naming method let us to study color appearance in terms of hue angle.…”