Patent attributes
Image measurement values of a measurement object, in particular a printed sheet, measured by means of a photoelectric image measuring unit operating on the basis of pixels are corrected with respect to at least one influencing variable which influences the measurement result with a view to at least partially eliminating the effect of this influencing variable on the measuring process. The image measurement values measured by the image measuring unit are converted by correction parameters of a parameter-based correction model into corrected image measurement values which no longer contain the influencing variable affecting the measuring process. The correction parameters used for the parameter-based correction model are automatically calculated using reference measurement values measured at reference measurements points on preferably the same measurement object by means of a reference measuring unit and the image measuring unit. In particular, image measurement values measured without polarization filters are converted into polarization filter image measurement values by means of this method. Influences induced by print medium, fluorescence effects and the influences of non-standard measuring geometries are also corrected.
