INVERSION OF THE NEUGEBAUER EQUATIONS

The Neugebauer equations are considered as the basic physical model fo r printing systems and, hence, they have often been used either in the ir original form or in any adapted version to model color printers. Th e main problem with printer models is that they relate color as a func tion of colorant values. in practice, however, the inverse relations i s needed and, hence, the printer model needs to be inverted. This is d one by making use of iterative techniques and, as a result, only one c olorant combination will be obtained to achieve a given color. However , in this publication it is shown that, in the case of Neugebauer mode l for three colorants, there are up to six solutions with which a give n color can be reached. Between these solutions there may be a number of pairs that are complex conjugated. Mathematical formulas to find al l these solutions are given. The extension of this inversion technique for more than three inks and for the localized Neugebauer equations i s presented. (C) 1996 John Wiley & Sons, Inc.