A Yellowness Index Simulation Model

Abstract

The yellowness index (YI) is a measure used in industry to quantify the yellowish of an object. With the advancement of computer vision, the YI can be measured using a simulation model instead of the costly measurement instruments such as spectrophotometer and colourimeter. A simulation method was established to transform the colour information of the digital image to CIE XYZ colour space and thus calculate the YI. The input image is obtained from a standard colour chart with the RGB value listed. The CIE XYZ and YI are obtained from the developed model and compared with those obtained from the RGB value listed in colour chart. The percentage of error (PE) between actual and simulated values for RGB, CIE XYZ, and YI are less than 1%. High coefficients of determination (R2) were obtained for YI as 0.9908. Based on the low PE and the high R2, we conclude that a CIE XYZ and YI measurement model is successfully developed.