A COLOUR GAMUT INDEX AND COLOUR-SHIFT INFORMATION BASED ON CIE 13.3

Author(s):  
Kees Teunissen
Keyword(s):  
2021 ◽  
Author(s):  
Guan-Hong Chen ◽  
Shao-Hsuan Yang ◽  
Chang-Wei Yeh ◽  
Shih-Jung Ho ◽  
Meng-Chi Liu ◽  
...  

2019 ◽  
Vol 2019 (14) ◽  
pp. 79-1-79-7
Author(s):  
Baiyue Zhao ◽  
Lihao Xu ◽  
Ming Ronnier Luo
Keyword(s):  

2015 ◽  
Vol 49 (3) ◽  
pp. 343-356 ◽  
Author(s):  
M Chakrabarti ◽  
A Thorseth ◽  
DD Corell ◽  
C Dam-Hansen

A white LED complemented by cyan and red LEDs is a good candidate for achieving high colour rendering at low correlated colour temperatures. This is usually very difficult with commercially available white LEDs. In addition, the system is able to replace incandescent lighting in many applications; for example, the lighting for museum display cases. To investigate and optimize the colour and light distribution properties, both spectral and geometrical modelling are used. Mapping of the possible combinations of LEDs is used to locate the optimal solutions within the colour gamut, with emphasis on chromaticity and colour rendering indices. A geometric optical model is used to design and optimize the homogeneity of the colour and light intensity distribution as a function of angle. The resulting system produces diffused homogeneous white light with a tunable correlated colour temperature from 2000 K to 2400 K. Within this range the white light is characterized by a high general colour rendering index (Ra > 90), special colour rendering indices for saturated red objects (R9 > 85), and low chromaticity distance (Duv) from the Planckian locus (Duv < 2 × 10−3).


2016 ◽  
Vol 49 (8) ◽  
pp. 992-1014 ◽  
Author(s):  
M Wei ◽  
KW Houser ◽  
A David ◽  
MR Krames

Two psychophysical experiments were conducted to investigate the effect of colour gamut size and shape on colour preference. In the first, two side-by-side booths were designed to resemble a retail setting with clothing; in the second, a single booth was designed to resemble a restaurant setting, but also included a mirror to permit the observer's evaluation of skin tone. These settings were illuminated with two sets of sources, where, compared to a fixed reference, one set created modest chroma enhancement and the other set created greater increases in object chroma. Within each set, gamut shape varied, meaning different hues were saturated, even though, on average, the spectra created the same average increase in chroma. When objects were unfamiliar, as with the fabrics, all chroma-enhancing spectra were preferred to the fixed reference regardless of the gamut shapes. When familiar objects were present, such as food, observers were more discerning about changes in chroma and hue. We conclude that a graphic of gamut shape is an important adjunct to average measures of colour fidelity and gamut.


2018 ◽  
Vol 51 (3) ◽  
pp. 353-372 ◽  
Author(s):  
X Tang ◽  
C Teunissen

The aim of this study was to evaluate differences in appreciation for LED-based white-light sources between Dutch and Chinese people, when used for the illumination of three applications: fresh food, packaging material and skin tone. Furthermore, the contribution of the CIE special and general colour rendering indices ( Ri and Ra), a colour gamut measure ( Ga), and chroma changes for specific test-colour samples to perceived attractiveness was investigated. Thirty-four Dutch and 36 Chinese people assessed the attractiveness of the object appearance, with paired comparison experiments, for seven light sources at two CCT settings, 3000 K (Dutch and Chinese) and 4000 K (Chinese only), and a range of Ra and Ga values. It was found that for illuminating fresh food and packaging material, most Dutch and Chinese participants preferred light settings with an increased colour gamut. In contrast to colour rendering indices, the chroma change for the strong red test colour sample could be used to predict object attractiveness, but the established equations were different per application and culture. There was no clear relation between objective measures and skin tone preference for the Dutch study. Finally, Chinese participants did not like an increase in red saturation at 3000 K, but they allowed an increase at 4000 K.


Optik ◽  
2018 ◽  
Vol 154 ◽  
pp. 216-225 ◽  
Author(s):  
Rui Gong ◽  
Xiandou Zhang ◽  
Xuan Li ◽  
Xiaopeng Shao
Keyword(s):  

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