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Title: Human perceptions of colour rendition vary with average fidelity, average gamut, and gamut shape

Abstract

An experiment was conducted to evaluate how subjective impressions of color quality vary with changes in average fidelity, average gamut, and gamut shape (which considers the specific hues that are saturated or desaturated). Twenty-eight participants each evaluated 26 lighting conditions—created using four, seven-channel, tunable LED luminaires—in a 3.1 m by 3.7 m room filled with objects selected to cover a range of hue, saturation, and lightness. IES TM-30 fidelity index (Rf) values ranged from 64 to 93, IES TM-30 gamut index (Rg¬) values from 79 to 117, and IES TM-30 Rcs,h1 values (a proxy for gamut shape) from -19% to 26%. All lighting conditions delivered the same nominal illuminance and chromaticity. Participants were asked to rate each condition on eight point semantic differential scales for saturated-dull, normal-shifted, and like-dislike. They were also asked one multiple choice question, classifying the condition as saturated, dull, normal, or shifted. The findings suggest that gamut shape is more important than average gamut for human preference, where reds play a more important role than other hues. Additionally, average fidelity alone is a poor predictor of human perceptions, although Rf was somewhat better than CIE Ra. The most preferred source had a CIE Ra value ofmore » 68, and 9 of the top 12 rated products had a CIE Ra value of 73 or less, which indicates that the commonly used criteria of CIE Ra ≥ 80 may be excluding a majority of preferred light sources.« less

Authors:
 [1];  [1];  [2];  [3];  [1]
  1. Pacific Northwest National Laboratory, Portland, OR, USA
  2. The Hong Kong Polytechnic University, Hong Kong, China
  3. The Pennsylvania State University, University Park, PA, USA
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1415089
Report Number(s):
PNNL-SA-116963
Journal ID: ISSN 1477-1535; BT0301000
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Lighting Research and Technology; Journal Volume: 49; Journal Issue: 8
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; TM-30; color preference; color normalness; color saturation

Citation Formats

Royer, MP, Wilkerson, A., Wei, M., Houser, K., and Davis, R. Human perceptions of colour rendition vary with average fidelity, average gamut, and gamut shape. United States: N. p., 2016. Web. doi:10.1177/1477153516663615.
Royer, MP, Wilkerson, A., Wei, M., Houser, K., & Davis, R. Human perceptions of colour rendition vary with average fidelity, average gamut, and gamut shape. United States. doi:10.1177/1477153516663615.
Royer, MP, Wilkerson, A., Wei, M., Houser, K., and Davis, R. 2016. "Human perceptions of colour rendition vary with average fidelity, average gamut, and gamut shape". United States. doi:10.1177/1477153516663615.
@article{osti_1415089,
title = {Human perceptions of colour rendition vary with average fidelity, average gamut, and gamut shape},
author = {Royer, MP and Wilkerson, A. and Wei, M. and Houser, K. and Davis, R.},
abstractNote = {An experiment was conducted to evaluate how subjective impressions of color quality vary with changes in average fidelity, average gamut, and gamut shape (which considers the specific hues that are saturated or desaturated). Twenty-eight participants each evaluated 26 lighting conditions—created using four, seven-channel, tunable LED luminaires—in a 3.1 m by 3.7 m room filled with objects selected to cover a range of hue, saturation, and lightness. IES TM-30 fidelity index (Rf) values ranged from 64 to 93, IES TM-30 gamut index (Rg¬) values from 79 to 117, and IES TM-30 Rcs,h1 values (a proxy for gamut shape) from -19% to 26%. All lighting conditions delivered the same nominal illuminance and chromaticity. Participants were asked to rate each condition on eight point semantic differential scales for saturated-dull, normal-shifted, and like-dislike. They were also asked one multiple choice question, classifying the condition as saturated, dull, normal, or shifted. The findings suggest that gamut shape is more important than average gamut for human preference, where reds play a more important role than other hues. Additionally, average fidelity alone is a poor predictor of human perceptions, although Rf was somewhat better than CIE Ra. The most preferred source had a CIE Ra value of 68, and 9 of the top 12 rated products had a CIE Ra value of 73 or less, which indicates that the commonly used criteria of CIE Ra ≥ 80 may be excluding a majority of preferred light sources.},
doi = {10.1177/1477153516663615},
journal = {Lighting Research and Technology},
number = 8,
volume = 49,
place = {United States},
year = 2016,
month = 8
}
  • In this editorial, written as an open letter to the lighting community, we stand in support of widespread adoption of TM-30-15: The IES Method of Evaluating Light Source Color Rendition. We introduce important considerations related to light source color rendition, define the need for a new method of evaluation, provide a high-level overview of the IES method, discuss some of the practical considerations related to the development of the IES method and the consensus process, and conclude by inviting you to join us in support of the new measures and graphics described in TM-30-15.
  • In this editorial, written as an open letter to the lighting community, we stand in support of widespread adoption of TM-30-15: The IES Method of Evaluating Light Source Color Rendition. We introduce important considerations related to light source color rendition, define the need for a new method of evaluation, provide a high-level overview of the IES method, discuss some of the practical considerations related to the development of the IES method and the consensus process, and conclude by inviting you to join us in support of the new measures and graphics described in TM-30-15.
  • Here, semiconductor nanostructures capable of emitting from two excited states and thereby of producing two photoluminescence colours are of fundamental and potential technological significance. In this limited class of nanocrystals, CdSe/CdS core/arm tetrapods exhibit the unusual trait of two-colour (red and green) multiexcitonic emission, with green emission from the CdS arms emerging only at high excitation fluences. Here we show that by synthetic shape-tuning, both this multi-colour emission process, and blinking and photobleaching behaviours of single tetrapods can be controlled. Specifically, we find that the properties of dual emission and single-nanostructure photostability depend on different structural parameters—arm length and armmore » diameter, respectively—but that both properties can be realized in the same nanostructure. Furthermore, based on results of correlated photoluminescence and transient absorption measurements, we conclude that hole-trap filling in the arms and partial state-filling in the core are necessary preconditions for the observation of multiexciton multi-colour emission.« less
  • We analyze mean fidelity between random density matrices of size N, generated with respect to various probability measures in the space of mixed quantum states: the Hilbert-Schmidt measure, the Bures (statistical) measure, the measure induced by the partial trace, and the natural measure on the space of pure states. In certain cases explicit probability distributions for the fidelity are derived. The results obtained may be used to gauge the quality of quantum-information-processing schemes.