Color mismatch and observer metamerism between conventional liquid crystal displays and organic light emitting diode displays

Abstract

Organic light emitting diode (OLED) displays use red, green, and blue primaries with a higher saturation level to produce larger color gamuts than conventional liquid crystal displays (LCD). No past study, however, experimentally investigated how such a difference between these two display types causes color mismatch and observer metamerism using the most widely used color matching functions (CMFs)-the CIE 1931 2° CMFs-for color calibration and specification. In this study, 50 human observers performed color matching tasks for six color stimuli with a field-of-view of 4.77° between four test displays (i.e., one LCD and three OLED) and a reference OLED display. The color gamuts of the LCD and OLED displays were similar to the sRGB and P3 standard color gamuts. It was found the CIE 1931 2° CMFs cannot accurately characterize the color matches between the LCD and OLED displays, with different chromaticities required to produce matched color appearance. Particularly, when the stimuli had matched color appearance, the chromaticities of the stimuli produced by the LCD display were all shifted towards the -u'+v' direction in the CIE 1976 u'v' chromaticity diagram in comparison to those produced by the OLED display. This suggested that using the CIE 1931 2° CMFs for display calibration would cause the colors shown on OLED displays to have a yellow-green tint if those on LCD displays appear neutral. In addition, a larger degree of observer metamerism was found between the LCD and OLED displays, while little differences, in terms of color mismatch and observer metamerism, were found between the OLED displays. The CIE 2006 2° CMFs were found to have better performance than the CIE 1931 2°, 1964 10°, and 2006 10° CMFs, which could be partially due to the size of the stimulus used in the experiment.