A Table-based Ink-reducing Approach with estimating ink limitation of media and Gray Component Replacement for Printing Devices

Abstract

In recent years color inkjet printers have been developed for home and office use. Color printing is accomplished by providing multiple layers of ink on a medium. However, excessive ink usage has caused problems, for instance, ink bleed, paper cockle, high operation cost, long drying time, slow printing, and so on. Therefore, a need exits to reduce the volume of ink used in printing images and thereby eliminate the foregoing problems. The first step of the proposed method for improving the problems is to estimate ink limitation on a medium by selecting reduced ink peak points which indicate that the top intensity of colorant signals is not the full value due to being reduced. And full ink peak points indicate that the top intensity of colorant signals reserves the full value as 255. To maintain a desired color lightness, chroma and hue value within a predetermined percentage deviation, the color difference of the color between reduced ink peak points and full ink peak points must be less than a predetermined color tolerance. The second step is to refer to the selected reduced ink peak points for determining calibration points for each ink color in the colorant space. The third step is to build a printer look-up table based on these calibration points. The final step is to combine Gray component replacement (GCR) to improve the performance of reducing ink here. Since GCR, a well known process in the printing arts, is also a valid method for reducing ink usage, because it can be used to print a single layer of black ink as a substitute for the combination of equal amounts of cyan, magenta and yellow.