Chromaticity gamut enhancement by heptatone multicolor printing

摘要: The present paper studies the chromaticity gamut of multi-color printing processes. Heptatone (7color) ‐ most promising variant offers a significantly larger than conventional CMYK process, approaching CRT and film gamuts. behavior process in device-independent CIE-XYZ CIE-L*u*v* colorimetric spaces is explored using compound Neugebauer model developped for this purpose. A simple straightforward Moire ´-free separation proposed. strong point proposed fact that only 3 different screen layers are needed any odd number basic colors including black. In today’s industry, 4-color (Cyan-Magenta-Yellow-blacK) state-of-the art technology. Numerous problems related to color separation, device calibration, gray balance fidelity have been studied since its invention by Alexander Murray 1934 ([HUN87], [WYS82], [YUL67], [MOL88]). Although it proves satisfactory majority cases, presents an important drawback: restricted when compared with gamuts displays or real dyes. Some saturated such as orange, certain reds, violet, purple, blue greens cannot be obtained printing. We propose extend introducing additional colors. This contribution modelizes extension 5-color, 7-color 9-color (7-color) has excellent considered optimal tradeoff between quality cost. modelization presented section 3. tool equation extended, 4, process. results discussed 5. Finally, scheme 6. our study gamuts, we used high-quality Pantonecompatible inks produced Swiss company SICPA printed them on coated paper. Colorimetric measurements were carried out Gretag SPM100 photospectrometer.