Reflectance and Energetic Imbalance: Colourmetric Evaluation of the NCS Colour Atlas

Résumé 0

"The NCS atlas was evaluated in two ways. The first provided a series ofexhaustive colourimetric measurements (reproduced in the electronicappendix available in http://www.uv.es/psicologica that were used for: (1)relating them to the descriptive parameters used by the atlas; and (2)analysing the general colourimetric properties of surface colours. The secondtype of evaluation examined the possibility of using the NCS atlascolourimetrically to specify colour tiles not belonging to it. The analysis ofthe relationship of the NCS with the colourimetric parameters showed thatevery NCS hue was associated with a specific chromatic angle and with onedominant wavelength. The relationships between NCS whiteness and CIElightness, on the one hand, and between CIE and NCS chroma parameters,on the other, were high but not so closed. When the atlas was consideredglobally, it was observed that lightness strongly determined both the stimulichromatic angle and CIE saturation. More specifically, for low lightness, thehighest CIE saturations were observed for the chromatic angles associatedwith either of the spectrum extremes or with the purple line. For highlightness, on the contrary, the highest CIE saturation levels were observedfor the chromatic angles related to the middle portion of the spectrum. Thesecond type of NCS evaluation considered its possible utility for inferringthe colourimetric parameters of samples not included in the atlas. Arelatively low error level (∆ E < 8) was detected, so it was concluded that theNCS atlas can be used for those practical applications that requirecolourimetric computations with medium or low levels of precision."