Comparison between the Color Properties of Whiteness Index and Yellowness Index on the CIELAB

Abstract

The color properties of a white or nearly colorless fabric are represented by whiteness index (WI) or yellowness index (YI). These two indexes relate to a white fabric's color quality. The purpose of this study was to identify the properties of WI and YI on the CIELAB through the simulations of estimation data for a systemization of color quality control. The results indicated that the relationship between WI and YI was a negative correlation, however the coefficients of correlation function between WI and YI were depended on hue. There were two hue transition points of the rate of changes in WI and YI. These hue transition points were the reference points to divide the hue contribution to WI and YI. These points were not the point of h=0 and h=180 and asymmetric. In addition, where the colors were same distance from the white point on the CIELAB, the rate of changes in WI and YI by <TEX>${\Delta}$</TEX>Ew were depending on hue. Specifically, when WI decreased, YI of reddish and yellowish tinted colors decreased more than bluish tinted colors.