Method controlling ink application in a printing press

Abstract

In order to control ink application in a printing press, a sheet (3) printed by the printing press (1) is colorimetrically measured in a number of pixels (4) with respect to a selected color coordinate system that has been expanded to be four-dimensional by also taking into account an infrared component. Color difference vectors with respect to the desired color vectors, predefined or determined from a reference sheet (3) and referred to the same color coordinate system, are computed from the color vectors obtained for each pixel (4). A sensitivity matrix is determined for each measured pixel (4) of the sheet (3). The pixels (4) are classified by sensitivity class. The color difference vectors and sensitivity matrices of the pixels (4) pertaining to the same sensitivity class are averaged for each sensitivity class, and input parameters, in particular film thickness modification vectors, are computed from the averaged color difference vectors and averaged sensitivity matrices of all sensitivity classes for a control unit (9) of the inking mechanisms of the printing press (1). The inking of the printing press (1) is then controlled on the basis of the input parameters thus computed.

Dependencies are inferred from the claim text.