A New Approach to Calibrate Color Scanner in EPS

Abstract

Calibration, based on Color Management System concept, may be defined as a means towards a device independent process; which in another term, is a method of standardization of RGB coordinates to be as CIE standards. In Electronic Prepress System (EPS), it is a must that a color scanner should be calibrated to ensure the color information of an original. Throughout experimental, it is found that the process of gray balance and tone reproduction adjustment of scanner responses is necessary before transformation (RGB → CIE L*a*b*). A linear matrix coefficients is possible, while other multiple regression is also applicable, as color difference values (AE) are less than 6.0. In addition, comparison is made with another technique using color space conversion RGB rarr; CIE XYZ through 1-D look-up table of tone adjustment. Similarly, the result is acceptable with linear matrix transformation. The special programs were developed for this purpose which enable to ease the software/hardware design and quick process in EPS.