Evaluation Of Digital Proof's Color Management System

The color management is the most important factor of digital proof. Traditional proof would be gradually replaced by the digital proof, since its advantage of high speed, high quality and low cost. The thesis's purpose was to put forward some methods to evaluate the digital proof's color management system, and analyze the main influence factors. They are benefit to extend the application of digital proof, and help users choose the right proof system. The results acquired might criterion digital proof's workflow, improve the quality of proof, also they have important significance in the digital printing's development and popularity.The study methods: Combined the Colorimetry with Statistics, formed the graph of color difference distribution according to the section of digital proof system's color target; Basic parameters of proof were acquired by spectrum density apparatus, Proof's chromaticity data were measured by spectrophotometer; Digital proof's gamut was analyzed with color solid chart; In order to obtain the best reproduction parameter for the controlling point, dotgain data were processed by least square method.The main works: (1) The basic structure of the most popular digital proof's color management system was analyzed and compared; After auto calibration, in the condition of color management to print the proof, the color difference between digital proof and offset proof was calculated. An evaluation project was completed from the analyzing result of color difference. (2) Under the setting of same ink, same software and hardware, output proof with different paper, acquired some mostly parameters, such as solid density, relative contrast, dot gain and trapping. The basic properties of substitute paper were presented in terms of the paper's gamut.The conclusions: (1) When the evaluation conditions and methods were confirmed, some factors were provided, including environment condition, valid printing target, number of the color batch, system error of measure apparatus and stability of output device. (2) During evaluating, not only the average and maximal color difference were considered, also the color difference distribution and the distributing region of some patches which had large color difference were reviewed, then, the controlling parameters of digital proof's color management system were achieved. (3) It was feasible to use the homemade paper instead of the special one. Gamut was one of the key factors to evaluate proof paper's printability.