Towards an optimum colour preference metric for white light sources: a comprehensive investigation based on empirical data

Abstract

Colour preference is a critical dimension for describing the colour quality of lighting and numerous metrics have been proposed. However, due to the variation amongst psychophysical studies, consensus has not been reached on the best approach to quantify colour preference. In this study, 25 typical colour quality metrics were comprehensively tested based on 39 groups of psychophysical data from 19 published visual studies. The experimental results showed that two combined metrics: the arithmetic mean of the gamut area index (GAI) and colour rendering index (CRI) and the colour quality index (CQI), a combination of the correlated colour temperature (CCT) and memory colour rendering index (MCRI), exhibit the best performance. Qp in the colour quality scale (CQS) and MCRI also performed well in visual experiments of constant CCT but failed when CCT varied, which highlights the dependence of certain metrics on contextual lighting conditions. In addition, it was found that some weighted combinations of an absolute gamut-based metric and a colour fidelity metric exhibited superior performance in colour preference prediction. Consistent with such a result, a novel metric named MCPI (colour preference index based on meta-analysis) was proposed by fitting the large psychophysical dataset, and this achieved a significantly higher weighted average correlation coefficient between metric predictions and subjective preference ratings.

Evidence for human-centric in-vehicle lighting: Part 2—Modeling illumination based on color-opponents

“…Current investigated illumination models for general indoor lighting preferences are primarily derived by a triplet based on correlated color temperature (CCT), vertical illuminance (E v ), and saturation enhancement (ΔC * ; Trinh et al, 2019 ) or without intensity dependency in a linear relation between color gamut (CDI) and color fidelity (Q a ; Huang et al, 2021 ). Further, combinations with non-visual parameters such as Circadian Stimulus (CS) were successfully established (Khanh et al, 2020 ).…”

Utilizing a strait-range green phosphor γ-AlON:Mn,Mg for the task of achieving a super-broad hue gamut display

“…The top emission wavelengths in the other illuminations were altered between 510 and 570 nm as well as 580 and 700 nm, respectively. We modified the illumination strength for each combination to produce a white illumination that yields a warm CCT measured at 3000 K that can be a substitute for traditional lights along with no divergence from the black body locus [13]- [15]. For each distribution, we calculated the CQS as well as LER.…”

Investigation of MAl2−xSixO4−xNx:Eu2+ phosphor for improving luminescence properties of white LEDs

“…As a result, in addition to the aforementioned methods, more innovative ways must be used to produce MAl2O4:Eu 2+ (M = Ca, Sr, Ba) phosphors satisfy such criterias. Alkaline-earth-silicon-nitride as well as oxynitride treated with Eu 2+ were recently demonstrated a discharge having a particularly lengthy wavelength as well as excitation inside the observable region of 370-460 nm [17]- [19]. If silicon and nitrogen atoms integrate into MAl2O4, MAl2−xSixO4−xNx: Eu 2+ is predicted to expand the lines of excitation towards the observable area as well as discharging under greater wavelengths, especially discharges in yellow as well as green caused by oxide being turned to oxynitride latticework.…”