Study On Methods Of Printing Image Quality Based On The Color-Difference Formula

With the increasing development of media technology, the imagebecame an integral part. Image quality assessment is an important areaof the image content, and its evaluation results must be consistent withthe visual sense. Objective evaluation of image quality based oncomplex algorithms, it is easier for digital images, while the printedimage is difficult to operate. And the results are not perfect betweenevaluation values and human visual experience. This difference is theobjective evaluation method not due to human visual experience. Thecolor is an important part of the image, the human eye perception ofcolor is more sensitive than others. Evaluation based on the needs forimage, a convenient method to evaluation image color difference wasfound in this paper. It provide a reference for the related industries.However, there is no method for evaluating image color-differencespecially. In1976the International Commission on Illumination (CIE)introduced the CIELAB color difference formula as the color standard.Based on this, some new color difference formula like CIE94, CMC,CIEDE2000were development. But, these traditional methods aremainly not aimed at the image color. They are good methods toevaluate the color difference between two uniform color samples, cannot used for two images. As the image is a combination of non-uniformand complex color samples, which contains a large number of differentcolors. The image color difference cannot be measured directly byinstrument, and the calculated results from original color-differenceformulas are not stand for the visual color difference sense. Thus, thereis the demand for establishing the link between objective andsubjective evaluation value based on visual experimental data andcalculation results. And the results from different color differenceformulas are different. Therefore, the ability assessment of different color-difference formula that predicts the image color-difference senseis very urgent and imperative research, and there is importanttheoretical significance and practical value.A large number of printing images samples used for subjectiveexperimental are produced, and two experiments (experiments and todetermine the level of subjective color threshold experiments) werecompleted is this study. Subjective experiment of imagecolor-difference levels evaluation is set up to establish the base data ofimage color-difference calculation. A large number of experimental datawas analyzed. The ability of some typical color-difference formulas thatevaluates image color-difference sense of is tested, including CIELAB、CMC、DE2000. They were improved in the ability to evaluates imagecolor-difference, and the CIELAB improved had the best performance.By refining the threshold test, threshold value of the image was got.Results show that the threshold value for printing images is muchsmaller than the digital images. This study provides basis data forevaluation and calculation color difference, the results can used asinstructive role for image printing and reproduction.