The Key Technologies Research On Color Management System Based On Digital Output Devices

With the development of computer, multimedia and the network technology Various color digital output devices have been significantly utilized in daily life and work.However, when the color images are transferred and reproduced from one digital output device to another, the color appearance of the images always disagree with the originals due to the color dealing mechanism and color gamut of the digital output devices being different from each other, which significantly affect the development in the related industries.The color management system is recognized as an effective way to resolve this problem.The key and fundamental techniques of the ICC color management system were studied in depth in this dissertation,color inkjet printer is selected as the typical representation of color digital output devices. Several corresponding model method and algorithm were investigated to achieve the digital devices color target suitable analysis,characterization define,color gamut boundary descriptions and color matching, Finally,series of subjective and objective evaluation index were proposed for the effective analysis for the research results.In this paper,on the basis of the device color management and tone compensation, the color matching adaptability was discussed between color targets and digital output devices, through the color adaptive analysis, a new optimization of color target model was designed based on Epson Stylus Pro7910digital output device. After experimental analysis,the results indicated that the new color target performed best in the use of reflecting the color adaptability in the digital output devices.Through the advantages and disadvantages of the currently used method and model were analyzed in color characteristics for digital equipments,a forward conversion of BP network model and partition reverse transformation model were put forward based on saturation is preferred. An experiment was designed to compare the new model with the current models, the results show that the new forward conversion model and partition reverse transformation model which proposed in this thesis are achieved high accuracy than others in color digital output devices.On the currently used color gamut description algorithm was discussed and summarized,combining the theory of tetrahedron subdivision, a kind of tetrahedron grid subdivision device gamut description algorithm model was proposed based on space region partition. On the basis of color target’s feature points, the optimal partition was discussed on respective color targets, and in-depth analysis on color matching adaptability was made between the color gamut boundary description algorithm and the color target. And then the improved Convex Hull color gamut boundary algorithm was realized and the matching effects were analyzed on this algorithm and color targets,relying on this algorithm and new color target, the comparative analysis on precision was discussed on the two color gamut boundary description algorithms. The results show that the effect of new color target with the two color gamut boundary description algorithm is much superior to the currently used color targets, and also show that the color gamut boundary description algorithm which was proposed in this dissertation is performed best in accuracy and precision than other related color gamut boundary description algorithms.The color gamut mapping algorithm was discussed and summarized due to its importance in the ICC color management system. Afterwards, a new gamut mapping algorithm was proposed in this study,namely,the neighboring replaced mapping algorithm based on the feature points. Through the human visual subjective evaluation and objective analysis, the comparative analysis in-depth between this new mapping algorithm and the two before color gamut boundary description algorithms.the results indicated that the matching effect between this new mapping algorithm and the new color gamut boundary description algorithm is obviously better in all than the matching effects with the improved Convex Hull color gamut boundary description algorithm. The results provide further evidence of the effectiveness and feasibility of the proposed algorithms in this dissertation.