Performance of advanced color difference and CAM02‐based formulas in prediction of the Crispening effect for reflective samples

Abstract

The Crispening effect is defined as an increase in the perceived color difference of the two stimuli, when their color (chromaticity or luminance) is close to the background on which the two stimuli are compared. In this study, the amount of the Crispening effect for three achromatic backgrounds and also the performance of six different color difference formulas (CDFs) for prediction of this effect have been investigated, by preparing 85 sample pairs in 9 CIE's recommended color centers. Regarding the results, the maximum (50%) and the minimum (4%) amount of the Crispening effect belong to the gray and the purple centers, respectively. According to the results of a comparative test, the Crispening intensifies when two stimuli have just lightness difference instead of just chromaticity difference. The highest variation was for the gray samples, in which the amount of the Crispening effect increased from 35% to 65%. By using PF/3 and STRESS index, it is also concluded that CMC and CIEDE2000 perform better than CAM02‐SCD and CAM02‐UCS in prediction of the Crispening effect on the dark gray and gray backgrounds. According to the results, the significant differences between the performances of the CDFs disappear when the luminance of the background increases. Huang's power functions also do not improve these results significantly. Furthermore, the results indicate that the traditional L* equation used in CIELAB performs similar to the Whittle's formula in prediction of the Crispening effect for reflective samples, and no significant difference was obtained.

Revisiting the weighting function for lightness in the CIEDE2000 colour‐difference formula

“…Displacements (in different senses) in the minima of the fitted V-shaped functions with respect to the value 50 are also appreciable for the BFD-P and BIGC-T2-M datasets. In other words, crispening may also be considered as a parametric factor [45][46][47] in place of a general correction to CIELAB, as proposed by CIEDE2000. While the reasons for the different (2) is modified at a time by a percentage of AE100%.…”

“…It must be recognised that very few curves in Figure closely resemble the prediction made by CIEDE2000, and we must admit that a clear lightness crispening may not be occurring in all datasets considered in Figure . In other words, crispening may also be considered as a parametric factor in place of a general correction to CIELAB, as proposed by CIEDE2000. In any case, it must be noted that the CIEDE2000 colour‐difference formula, with its corresponding S L function discussed in the present paper, was proposed for a specific set of viewing conditions , including a neutral background with L * = 50 and samples without gloss and texture, which is not the case for all datasets we are considering in Figure (see Table ).…”

“…This replacement leads to a new colour-difference formula with no statistically significant difference with respect to CIEDE2000. As a related example, another recent paper [46] has reported a non-significant statistical difference between results found using CIELAB lightness and the Whittle formula. As a related example, another recent paper [46] has reported a non-significant statistical difference between results found using CIELAB lightness and the Whittle formula.…”

“…The usefulness of the Whittle formula as a model for grey scales in self‐luminous devices and also for the development of new colour‐difference formulas for surface colours is the possibility we are offering for further research. As a related example, another recent paper has reported a non‐significant statistical difference between results found using CIELAB lightness and the Whittle formula. For the moment, we must say that statistically significant improvements (the important matter in real practice) upon currently recommended CIE/ISO standard formula CIEDE2000 have been reported for 9/13 datasets considered in the present paper, plus some additional datasets considering large colour differences, by using a power function with exponent 0.70 .…”

The influence of the chromatic effect of crispening on the shift in the manifestation of the color of the observer

“…In their 2017 research, scientists Karimipour and Gorji conclude the following: "According to the results of a comparative test, the crispening intensifies when two stimuli have just lightness difference instead of just chromaticity difference" [9]. Furthermore, scientists Kane and Bertamlio examine in their paper the perception of light and the manifestation of the crispening effect with the help of five different variations of background lightness from 0% to 100% of illumination, and they analyze the perception of light and the evaluation of contrast [10].…”