Measurements of individual color matching functions to solve the discrepancy in color appearance among color display devices

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The purpose of this study is to deal with the problem of the mismatch of the tristimulus value when the metameric match is achieved among different color devices, by assuming that the color matching functions, which can be used to calculate tristimulus value, have significant individual differences. In order to achieve our goals, we firstly need to develop a compact apparatus to measure color matching functions precisely, and a method of estimating color matching functions with our apparatus. Then we need to verify our method, followed by collecting data on many observers to clarify the individual differences and that deviation from CIE Standard Observer.We developed an apparatus that can present arbitrary combinations of the monochromatic lights with a Maximillian view system. Also we developed an algebraic method using M series to present independent sets of monochromatic lights to the observer to obtain color matching functions. By comparing our method with a traditional method, maximum saturation method, it turned out that our method is less noise-tolerant than MSM. As our method is based on the matrix operation, the noise in a specific stimulus penetrates to other parts, while in the MSM the noise is restricted to that stimulus. The satisfaction of the match, on the other hand, is much higher in our method as the reference stimulus remained constant through all the experiment.10 subjects participated in our experiment as an observer, and the estimated CMFs showed individual differences, not only in the B CMFs but also in G and R CMFs.We also conducted metameric color matching experiment between a color paper and a CRT monitor, and tried to compensate individual differences of CMFs to obtain customized tristimulus values. The color differences, or Eucrid distance, between the tristimulus values of two different media showed a trend that customized tristimulus values give smaller values than those calculated from Standard observers.