An Analysis And Improvement Of Precision Of Prepress System Color Transfer Output Process

The introduction and extensive application of devices characterized by informationization in the field of prepress makes prepress system configuration more flexible and more convenience to prepress CMS (Color Management System). At the same time, some possible negative effects of prepress CMS are brought in. Accurately communicating and reproducing color information have always been being the color management system's target and an important subject for study among different devices.Since monitor and color ink jet printer are important display and output devices of computer, it is a significant and absolutely necessary work to investigate their characteristics.In this paper, starting from the actual requirement of prepress system color management, combining CRT monitor and printer, on the basis of three-dimensioned lookup table with interpolation algorithm theory, by the establishment of equipment characteristic model and gamut mapping algorithmic, I have completed to build the prepress color management system, designed and developed color management prototype system, done experiments and analyzed. The completed work and results obtained are as following:1. By analyzing CRT and printer working principle and presenting color characters ,combined with CIE CIE 1976 L*a*b* chroma system, a gamut mapping arithmetic from monitor to printer based on 3-D lookup table with interpolation algorithm theory is provided.2. Using 3-D lookup table with interpolation algorithm, a monitor and a printer characteristic model are established. Then a printer calibration model is established by using improved 3-D lookup table with interpolation algorithm. Tested by practice, the equipment characteristic models have reached upper precision. The chromatic aberration average value between equipment measure value and model calculate value is rather less than the smallest scope that human perceived.3. A gamut mapping algorithm from monitor to printer that based on improved 3-D lookup table with interpolation algorithm has been realized. The color error transferred from monitor to printer has been slashed after the gamut mapping between monitor and printer.4. An experiment precept was devised and experiments were done. A color management prototypesoftware system is developed on MatLab 7.0 platform. The monitor and printer characteristic model and printer calibration model have been established by using experiment data. Gamut mapping are realized on the basis of equipment models. All the equipment models and gamut mapping method have been analyzed.