Evaluating Display Color Capability

Abstract

Although the CIE recommends using the 3D CIELAB color space to assess displays, a 3D CIELAB gamut plot can be difficult to calculate, render, and interpret. Here, a team of experts demonstrates why the gamut rings plot may be a better alternative.

Overview of the Newly Released IDMS

“…As reinforced in recent publications, 3,4 and as explained in the new IDMS (section 21.3.2), color gamut is a volume. * It is critical to use three-dimensional tools that consider the lightness axis, in addition to chromaticity, to properly represent any display's color capability.…”

Color Capability of RGB Laser Displays

“…For some displays, this condition is not met, and consequently there is no longer any significant correlation between the chromaticity gamut area and the color gamut. 4 Although images always are encoded using an additive color model, the display system designer or end user may choose to map the input signal to the optical output in a nonadditive way, even though this would compromise the color accuracy. For example, some applications may require text legibility under strong ambient light, whereas color capability is of less importance.…”

“…where LQ is the luminance (illuminance for a projector) of the display for input signal Q . For some displays, this condition is not met, and consequently there is no longer any significant correlation between the chromaticity gamut area and the color gamut 4 …”

Gamut rings of reflective ePaper displays with combined frontlight and ambient illumination

“…Recent standards have proposed representing the CIELAB color gamut envelope in two dimensions, in a so-called Gamut Ring diagram. 10,[13][14][15][16] The CIELAB color gamut volume method with its 2D Gamut Rings representation was originally demonstrated for self-luminant displays. However, reflective displays require a different implementation of the gamut volume method.…”