A study on quantifying color appearance of translucent material

The study intends to develop a single number pass/fail formula that can accurately represent the perceived color differences regardless of reference conditions, physical properties of sample pairs, and types of material. To accomplish the research objective, the study is divided into two parts. The first part presents a study on investigating and developing a new color difference formula and testing its performance against the existing formulas with various different settings. A new color difference formula based on Mahalanobis distance approach was developed using several different sets of perceptual data that have been established under various experimental conditions, using samples representing a diverse range of substrates and different groups of observers. The performance factor PF/3, a measurement of disagreement between computed and perceived color differences, for this proposed color difference formula shows that the formula outperforms other existing color difference formulas.;The second part of research study presents a study on developing a combination of new methods/techniques and color difference formulas to measure, evaluate, and control the color appearance of translucent materials. The combination of color difference formula based on Mahalanobis distance and weighted average Delta E* model was proposed and proved to provide the most accuracy and significantly high correlation to the visual assessment. The only limitation of this technique is that the significantly additional inspection time is required. A followed-up study was performed to eliminate this limitation. The combination of color difference formula based on Mahalanobis distance approach and the weighted average model using a measurement technique based on Kubelka-Munk theory was proposed. The F test results confirmed that this combination can measure the quantitative color difference accurately and provide the highest correlation to visual assessment of translucent materials with the significantly least amount of inspection time.;The findings of this research are expected to contribute a new inspection and quality control methodology that provides higher accuracy and less dependence on subjective judgment for industries producing products with color-related quality characteristics, especially for translucent material.