Calibration of a multilevel inkjet process
View Patent ↗A multilevel printing process can be calibrated by: measuring a small number of recorded patches obtaining data points characterising the printing process, modeling a gradation of the printing process with a model curve incorporating different gradation behaviour of the printing process in different regimes based upon the obtained data points, and using the model curve to obtain a gradation-correction curve for calibrating the printing process, where it is sufficient to use only patches obtained by filling every pixel in a patch with a same recording level.
1. A method for calibrating a multilevel printing process, comprising the steps of:
measuring an optical density or colour of a small number of recorded patches obtaining data points for the printing process,
modelling a gradation of the printing process with a model curve incorporating different gradation behaviour of the printing process in different regimes based upon said data points,
using the model curve to obtain a gradation-correction curve for calibrating the printing process,
characterised in that the measured patches substantially comprise only patches obtained by filling every pixel with a same recording level.
2. Method according to claim 1 wherein said measured patches comprise only patches obtained by filling every pixel in the patch with the same recording level.
3. Method according to claim 1 wherein the model curve is obtained by linear interpolation in between the data points obtained by measuring said patches.
4. Method according to claim 1 wherein the multilevel printing process is an inkiet printing process.
5. Method according to claim 4 wherein recording levels correspond to drops of different drop sizes.
6. Method according to claim 4 wherein recording levels correspond to different drop counts.