Color conversion for a multi‐primary display using linear interpolation on equi‐luminance plane method (LIQUID)

Abstract

Abstract— A color‐conversion method, which converts an XYZ tristimulus value to a set of display signals for a multi‐primary display, has been developed. It is necessary for a display‐device driver in a color‐management system to select an optimal set of display signals that presents a given colorimetric value on a display screen. A multi‐primary display, which has more than four primaries, has more than two sets of display signals that generate the same colorimetric value theoretically. A display‐device driver, therefore, has to be designed according to a certain rule in order to choose a unique set of display signals for one colorimetric value only. To meet the requirement, a linear interpolation method, which uses three points on an equi‐luminance plane in XYZ tristimulus value space, has been developed. The developed method assigns three points on an equi‐luminance plane in XYZ tristimulus value space to ensure smoothness of a continuous gradation of display signals. The colorimetric accuracy of the developed method was evaluated with a six‐primary DLP™ projector. Colorimetric error in CIELAB space between the targets and reproductions is about 0.8 on average and 2.9 at maximum.