Feasibility Study On Red Color Evaluation Of Corals Based On The Gemdialogue Color Card

The color is an important indicator of quality assessment and value assessment.The paper supports the theory of colorology and combines the red characteristics of corals to quantify the red color of corals,classifies and divides the characteristics of coral red color after quantification,and establishes a reasonable color quality evaluation system.The paper is devoted to the feasibility of GemDialogue color card for the evaluation of coral red color quality.Based on the CIE 1976 L*a*b*uniform color space,using the X-Rite SP62 portable spectrophotometer to measure Gemdialogue color card,which contains P2R,MAG,R,O2R,R2O.The paper selected three lighting conditions:D65,F2,and A.The test color parameters include L*,a*,b*,C*,and h₀.A total of 38,250 experimental data were measured.By exploring the color parameter variation law,distribution characteristics and color performance of color cards and samples under different test light sources,D65light source was selected as the light source for coral color quality evaluation.Taking Aka coral as an example,combined with Aka coral red characteristics and industry standards for coral color grading,1372 sets of data were obtained that were consistent with Aka coral color quality evaluation.Using the hue angle h₀ as a variable,the experimental data was analyzed by K-Means rapid clustering using SPSS 25.0software,which was divided into 3 categories.Classification results are satisfactory.Fisher's discriminant analysis verified that the correct rate of return was 100%,further indicating that the clustering results were valid.K-Means rapid clustering analysis was carried out on L*,a*,b*as independent variables for different types of hue experimental data,and 5 types of hue angles were subdivided into 5,5,and 7 categories.Classification results are satisfactory.Fisher discriminant analysis verified that the correct rate of the above classification results was above 97%,indicating that the clustering results were valid.Integrate the above classification results,and describe the classification results of different tones by using the L*and C*as observations.The final classification scheme:Red series:Deep Red,Intence Red,Vivid Red,Red,Light Red.Orange-red series:Deep oR,Intence oR,Vivid oR,OR,Light oR.Red-orange series:Vivid rO,Vivid Light rO,Intence rO,RO,Light rO,Deep rO,Dark rO.This paper has done a complete test on the red part of the Gemdialogue color card.The data can be filtered according to the color characteristics of different red gemstones.