Based On Lcos Digital Printing, Color Management System

The market of digital photofinishing is greatly stimulated by the popularization of digital camera. However, the domestic technology is far lower than the overseas. A good chance is provided for the domestic digital photofinishing with the application of LCOS technology. Based on the technology analysis and market investigation, color management system(CMS) will be the key to decide the future of LCOS digital photofinishing, and it is also the key to decide whether domestic digital photofinishing can break foreign monopolization. Considering the characteristic of hardware, the following innovations will be made in this dissertation.Gamut Mapping: Based on the colorimetric prediction of CRT's gamut and printing paper's gamut, the traditional gamut mapping algorithm(GMA) is improved from two aspects, mapping direction and mapping method. For mapping direction, the weighted formula of visual color difference is proposed and the three-dimensional mapping model is designed. For mapping method, the balance is made between the clipping method and compression method, which generates a virtual gamut region, and the non-linear compression is performed.Gamma Adjustment: Based on the characteristic of digital photofinishing and the photoelectric characteristic of LCOS, Gamma adjustment flow is designed with the mathematical feedback method. The main parts include density adjustment, exposure adjustment, pre-printing adjustment and uniformity correction. In the application, the difference of LCOS characteristic, the imaging uniformity and the color error caused by developing environment are adjusts effectively.Color Space Conversion: The color space conversion with three-dimensional lookup table(3D LUT) method and artificial neural network(ANN) method is studied. The tools like IT8, ColorSync and so on generate most of currentcolor-management-systems, so the tetrahedral dividing of gamut is discussed from building table. For ANN method, the combination algorithm of dynamic self-adapting and evolution programming is proposed, and the convergence of network is improved effectively.Software System: Software provides operation system for the digital photofinishing and it directly influences the reproduction quality. The main modules include configuration module, hardware controlling module, image browsing module, image processing module and so on. The software system is very complicated and only the key parts will be introduced briefly in the dissertation.The application of the discussed model is still at beginning stage. It can be predicted that the development of LCOS digital photofinishing industry even the whole digital photofinishing industry should be speeded up with its farther application.