engleski

Gamut Characteristics of Chromatic and Identical Desatured Achromatic Reproduction

An important number of parameters decide the quality and fidelity of graphic imprints ; among them many are gamut related or gamut influenced. The research conducted in this paper attempts to define influences that different combinations of rendering methods, as a function of transferring and gamut mapping in reproduction process, have with a various starting color spaces of the original used in graphic technology. Three different subsections of the test form have been created for research purposes ; unsaturated achromatic, chromatic and section for instrumental analysis, stored in three various color spaces: RGB, CMYK and CIE L*a*b. Each of the samples was rendered with perceptual, saturated, relative and absolute colorimetric methods, and then printed on two different types of printing machines (dry and liquid toner principle) on an identical printing surface, in the same environmental conditions. Based on the information obtained by spectrophotometric measurements conducted on a whole subject for instrumental analysis, for each of the 24 samples, in CIE L*a*b* color space, single and parallel gamut preview have been constructed and their volume calculated. Three different methods of visual preview evaluation have been examined, separately for chromatic and restructured (desaturated) achromatic, in standard prescribed conditions, using simultaneous binocular method. Choosing the best sample was the evaluation criteria ; firstly between sets of proposed samples of different rendering methods for each color space, secondly between various individual color spaces for each given rendering method, and thirdly between sets of proposed diversely rendered samples for a given color space, on a reference computer screen. Based on the obtained results, situations have been defined, and it was possible to establish which rendering method, in combination with initial color space for chromatic or desaturated achromatic reproduction, depending on a type of the digital printing machine, gives specific results related to the gamut.

gamut; color space; rendering method; achromatic and chromatic reproduction

nije evidentirano