Performance of lightness difference formulae

Abstract

There are large variations between different previously published lightness difference experimental data sets. Two hundred and eight pairs of matt and glossy paint samples exhibiting mainly lightness differences were accumulated. Each pair was assessed about twenty times by a panel of fourteen observers using the grey scale method. The results were used to derive a new lightness difference formula (CII), and to a large extent, a possible new CIE lightness difference formula (CMC99). Both formulae were found to be more accurate than the typical deviation of an individual assessment from the mean of a panel of 20 observers, and outperformed the existing formulae using the present data set. The new CMC99 lightness difference formula is integrated into the new CIE colour difference equation CIEDE2000. The results also showed that special attention should be paid to measuring very dark samples. This is caused by poor instrument repeatability and inter‐instrument agreement in this colour region.

Dental ceramics: A CIEDE2000 acceptability thresholds for lightness, chroma and hue differences

“…3,4 Recent experimental results showed that the L* scale gives too large DL* values for lightness differences both for dark and for light samples. 27 Therefore, in CIEDE2000, lightness is corrected with a specific weighting function (S L ). However, our results (Fig.…”

Revisiting the weighting function for lightness in the CIEDE2000 colour‐difference formula

“…While most of the datasets employed here covered wide regions of colour space, the two NCSU datasets analysed only very specific regions: low saturated blue [33] and black [34]. Among these viewing conditions, we include the material of the samples (related to its texture), because it may play a role in the optimal S L function [18,21] we are looking for, and also the lightness of the background, because it is necessary information to calculate Whittle's formula [37]. In addition, Table 2 provides information on the main viewing conditions for each of the 13 visual datasets.…”

Colour-difference assessment

“…It was observed (Chou et al ., 2001) that perceived lightness difference is smallest for the darkest and lightest sample pairs, and the largest difference occurs for L * of 50. These results are consistent with the majority of the earlier work in that Δ E / Δ V (instrumental/visual perceptible difference) clearly increases as L * increases from L * = 50.…”