Thesis (M.Sc.)--Chulalongkorn University, 1999

To match the colour print of the colour copier and the offset proof, a colour management system is needed. The purpose of this research is to develop the colour management system (CMS) for producing a proof from copier as an offset proof. In the study, the 2 profiles were developed; the first profile was calculated from 614 colorimetric values and the second profile was calculated from the 2 divided groups of colorimetric values. The Standard Colour Image Data : SCID (ISO12640) with the RGB data were used to produce both the offset proofs from proof press and colour prints from the colour copier. Then colorimetric values of the two processes were measured. The relationship between XYZ of the proofs and RGB of the original of the two systems were obtained by using the Multiple Linear Regression. The average colour different (triangle E) of the print-out with the first profile is decreased 35% and the average triangle E of print-out with the modified profile is decreased 58%. And the tone reproduction of ht eimage from the second profile is better than that from the first profile