Analyzing the metrics of the perceptual space in a new multistage physiological colour vision model

Abstract

In this work, the metric of a new multistage colour vision model, ATTD05, is assessed and a new colour difference formula is suggested. Firstly, the uniformity of the ATTD05 colour space was compared with that of CIECAM02 for some Munsell samples, because if the model yields a uniform perceptual space, we will be able to implement a colour difference formula as a Euclidian distance between two points. Secondly, we developed a new space based on the perceptual descriptors of the model: brightness, hue, colourfulness, and saturation. After that, we calculated the free parameters of the space that better fit the measured and experimental data of two datasets (small-magnitude and large-magnitude colour differences), by minimizing the performance factor (PF/3). Finally, we compare colour differences calculated for ATTD05 and for other models. The PF/3 and the STRESS parameters were used to decide which model predicts better perceptual differences and, therefore, which model was the more uniform.

Setting tolerances on color and texture for automotive coatings

“…Although the performance of the various color difference equations has been thoroughly tested, it is still unclear which equation is best suitable for high gloss effect coatings with small color differences as used in the automotive industry. Studies show no significant difference in performance between dE CMC and CIEDE2000 or CIE94 . A small preference for CIEDE2000 was found in some other studies, but a statistically significant improvement was only reported in Refs.…”

“…Studies show no significant difference in performance between dE CMC and CIEDE2000 or CIE94. [12][13][14][15][16][17][18] A small preference for CIEDE2000 was found in some other studies, 8,[19][20][21][22] but a statistically significant improvement was only reported in Refs. 11, 23. Inconsistencies in these results are partly due to the different compositions of the sample sets the equations were tested on.…”

Analysing the color uniformity of the ATTD05 perceptual space

“…Since the locus of constant Chroma are more circular (with one exception), the Chroma spacing indexes for all Values and the hue spacing indexes for all Chromas and Values are also lower, and the eccentricity of the centre of gravity for a given Value and the corresponding index of dispersion of the centres of gravity for the rings of the population for that Value are in the some order (again with few exceptions), we conclude that the perceptual space of ATTD05 has a higher degree of uniformity than that of CIECAM02. Consequently, a useful colour difference formula can be implemented [25].…”