Research On Color Space Of Multiple-ink Printer

Conventional four-color printing systems are limited by an insufficient number of degrees of freedom for tuning the visible region of the spectrum. The goal of this paper is to find eight inks which can minimize the metamerism between original and reproduction, and predict the spectral reflectance of ink overprint. In the second chapter, theory background of the paper is introduced, including multiple-ink color system, and Kubelka-Munk turbid media theory, and vector representation for colorants, and linear modeling techniques, and several spectral printing models. In the third chapter, CIE1976L*a*b* uniform color space and its color difference formula is introduced, and the development of color difference formula is introduced simply, the CIE94 and CIEDE 2000 is analyzed deeply, the discontinuity of CIEDE 2000 color difference formula is pointed out so that we can avoid inherence error in the calculation process using CIEDE 2000 color difference formula. In the fourth chapter, eight color is selected which can minimize the metamerism between original and reproduction, first estimate seven color ink (one of the eight color ink is black) according to CIE 1931 XYZ chroma chart, to be the reference of the eight colors; then do spectral analysis of original, evaluate and assured the eight colors, use principle component analysis statistic the spectral information and decompose these information into a subspace of 31 dimensions spectral space while the dimension of the subspace can describe the mostly change of these measure spectral samples; using vector correlation and continuous tone approximation to select eight inks that have the mostly similar optical performance with the basic colorants. In the fifth chapter, predict the spectral reflectance of ink overprint using Kubelka-Munk turbid media theory. In the last chapter, do experiment in this paper and analysis the results.