Loci of neutral and preference white for laser-based wide color gamut displays

The correlated color temperature (CCT) of a display's white point may vary depending on adapting illumination and user preference. To determine the optimal white-point chromaticity at each CCT for laser displays characterized by wide color gamut and narrowband spectra, this study aims to establish neutral and preferred white loci. To identify these loci, we have adopted the paired comparison method to collect the most neutral and preferred white points along multiple iso-CCT lines. The experiment utilized 5 images, each rendered with 162 different white point chromaticities (18 CCT × 9 Duv). Results indicate that the neutral white locus closely aligns with the preference locus. When using the CIE 1931 CMFs (color-matching functions), the white loci were consistently below the Planckian locus, with slight variations across CCT. While the Duv values of white loci vary substantially with the CMFs employed to estimate chromaticity. Moreover, regardless of which CMFs are selected, the fitted white loci are aligned with the major axis and remain parallel to the Planckian locus within the ellipse of the perceived white region, but show a nonlinear relationship outside it.