Authors: Ying Guo Huan Wang Hongmei Du
Publish Date: 2016/02/18
Volume: 75, Issue: 22, Pages: 14491-14502
Abstract
Based on the uniform color space International Commission on Illumination CIE 1976 Lab the color green of 728 pieces of jadeitejade was quantitatively characterized by the spectrophotometer Color i5 The colorchip system of jadeitejade green with color difference control was then researched First with the help of the basic color difference formula the concentrated plot areas of L∈35 55 a∈−30 −45 and b∈0 35 of jadeitejade color green were taken as the color center which was in accordance with the CIE standard green L = 56 a = −32 b = 0 and high chroma green L = 56 a = −45 b = 0 Second the total plot areas of h0∈12521° 17110° and L∈5 95 of jadeitejade color green were considered as color gamut which was in accordance with the scope from CIE standard yellowish green to bluish green In consideration of the color green plot areas of jadeitejade and China National Standard GB/T 23885–2009 “JadeiteJade Grading” ΔL = 5 Δa = 10 and Δb = 10 were calculated to form a colorchip system of jadeitejade color green with ΔE = 15 from one chip to another and 521 chips were then achieved Color chips were reduced or added for sparse or intense plot points As a result the colorchip system was condensed into 126 chips based on lightness and then merged into 19 areas with ΔL = 5 With cluster analysis 126 chips were graded into nine levels The commercial evaluation of jadeitejade color green showed that these levels were sequenced from the top quality fancy vivid green to the last faint green Oneway ANOVA verified the reasonability of the nine levels Fisher discriminant analysis demonstrated that very high accuracy of 9921 was achieved and only one group from 126 groups was misjudged Thus based on the statistical analysis of color parameters in the uniform color space the colorchip evaluation system of jadeitejade green with color difference control could be used with high accuracy
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