Abstract: The K-M theory points that there is a linear relationship between the K/S values and the dye concentration. In practice this linear relationship is not obvious, so most of the software is logarithmic curve fitting way to establish a database. In semi-transparent situation of dye, the linear relationship of K/S is worse, the above mentioned method has failed to meet color accuracy requirements. In this paper, we collected multiple semi-transparent samples and removed invalid points, then did cubic spline interpolation for the remaining valid points, and corrected reflectivity in low concentration points to make it more consistent with the linear relationship hypothesis of K-M theory. Experimental results show that the above-described method can significantly improve the accuracy of color match.

Key words: spline interpolation, semi-transparent color match, reflectivity correction, scattering coefficient, absorption coefficient