Effects of adapting luminance and CCT on appearance of white and degree of chromatic adaptation

Abstract

Past studies reported that the degree of chromatic adaptation was affected by viewing medium and adapting luminance. In this study, human observers adjusted the color appearance of a stimulus produced by a self-luminous display to make it appear as white as possible under different adapting conditions, whose adapting luminance and Correlated Color Temperature (CCT) levels were systematically varied. Though an identical display was used as the viewing medium, the chromaticities adjusted under the high adapting luminance levels were generally around the adapting chromaticities, which was similar to the findings in the past studies using reflective surface color samples as the viewing medium. This suggested that the effect of the viewing medium, as reported in the past studies, was actually the effect of viewing mode, due to the change in adapting luminance. Furthermore, the adapting luminance and CCT were found to jointly affect the degree of chromatic adaptation, with a stronger effect of adapting luminance under a lower adapting CCT. 42 92 where: D: the degree of chromatic adaptation factor (between 0 and 1); F: a surround parameter, with 1.0 for an average surround, 0.9 for a dim surround, and 0.8 for a dark surround;L A : the adapting luminance level.

Investigation on effects of adapting chromaticities and luminance on color appearance on computer displays using memory colors

“…When the adapting condition was 9719 K, the chromaticities of the gray cube shifted toward a lower CCT. Such a trend of the chromaticity shift was very similar to those in past studies investigating the chromaticities for producing neutral colors (ie, white or gray) on displays 9,12,13,15,16 …”

“…Four adapting CCT levels (2856, 4500, 6500, and 9000 K) were designed. Our past experience suggested that a same adapting CCT would have very different appearances when using viewing booth and self‐luminous display, which was likely due to the incomplete chromatic adaptation caused by the viewing mode when viewing self‐luminous displays 13 . When viewing stimuli in the self‐luminous mode, the neutral colors at low CCT levels appear much chromatic (i.e., yellower).…”

“…Recently, Wei and Chen carried out two experiments in which observers adjusted the color appearance of stimuli that were produced using a self‐luminous display to make the stimuli appear white under various adapting CCT and luminance levels. Based on the corresponding white colors, the adapting chromaticities and luminance were found to jointly affect the degree of chromatic adaptation 12,13 . Therefore, this study is a continuation of these two recent studies, with a goal to investigate chromatic adaptation on computer displays using various chromatic colors through memory color matching.…”

Testing the performance of CIECAM02 from 100 to 3500 cd/m2

“…Both the MCDM values for the intraand inter-observer variations were comparable to those reported in several recent studies employing memory color matching. [15][16][17][18][19] 2.4.2 | Chromaticities of the adjusted stimuli Figure 3 shows the chromaticities of the reference stimuli and the average chromaticities of the adjusted stimuli in the CIE 1967 u 0 10 -v 0 10 chromaticity diagram. It can be observed that the average chromaticities that were adjusted under the higher L w were closer to the blackbody locus, suggesting the stimuli under a higher adapting luminance appeared less colorful.…”

“…The magnitudes and ranges of the inter-and intra-observer variations were generally comparable to those in experiment 1 and past studies. [15][16][17][18][19] 3.3.2 | Chromaticities and color attributes of the adjusted stimuli Figure 8 shows the average chromaticities of the adjusted stimuli and the chromaticities of the reference stimuli in the CIE 1976 u 0 10 -v 0 10 chromaticity diagram; Figure 9 T A B L E 4 Colorimetric and photometric characteristics of the adapting conditions in experiment 2 shows the chromaticities of the adjusted stimuli in the a 0 10 -b 0 10 plane of CAM02-UCS, with the adapting luminance being included in the calculations. It can be observed that the chromaticities of the adjusted stimuli under the different adapting luminance levels were close to each other, as shown in Figure 9, which seems to illustrate that the CAM02-UCS can accurately predict the color matches.…”