共查询到19条相似文献,搜索用时 146 毫秒
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荧光纸基的双面彩色半色调印刷品Clapper-Yule正面反射率模型 总被引:1,自引:1,他引:0
目的研究荧光纸基对双面彩色半色调印刷品反射率的影响。方法假设油墨与纸张的折射率相似,考虑到荧光部分可以吸收光线中不可见的紫外光,经过能量转换散发出可见光从而影响总反射率,将这部分影响等效于正、反面油墨的透射率,以及纸张内部向正、反面反射率的改变;考虑光学网点扩大因子,利用Clapper-Yule分程理论进行分析;通过数值模拟,对新、旧模型进行比较,验证新模型的合理性和准确性。结果建立了荧光纸基的双面彩色半色调印刷品Clapper-Yule正面反射率模型。结论色彩预测Clapper-Yule反射率模型必须考虑荧光纸基的影响。 相似文献
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首先介绍了经典的Kubelka-Munk理论及其Saunderson校正,并在此基础上推广到半色调印刷品中,考虑到光在印刷品中的横向散射,引入了散射概率函数描述光子从一个界面元进入而从另一个界面元射出的概率,建立了一个统一的半色调印刷品光谱反射预测模型. 相似文献
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目的以反射率为基准,对透明非吸收性材料进行分色建模。方法通过入射光照射到透明非吸收性材料后经历的多重内反射及透射,建立基于CYNSN的透明非吸收性材料网点面积率,预测光谱透射率的模型,并确定优化后的Yule-Nielsen指数n和胞元等级数量,在印有底白的透明非吸收性材料上打印检验样本数据,以该数据为分色基准,基于线性回归迭代算法,建立透明非吸收性材料CYNSN透射稿分色模型。结果该分色模型能够达到比较高的分色精度,并且避免了分色过程中使用光谱透射率测量仪器,降低了成本,提高了数据测量效率,使透明非吸收性材料分色效果更加接近于反射稿。结论该模型是一种有效的透明非吸收性材料分色模型。 相似文献
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Hébert M Hersch RD 《Journal of the Optical Society of America. A, Optics, image science, and vision》2006,23(10):2415-2432
We propose a spectral prediction model for predicting the reflectance and transmittance of recto-verso halftone prints. A recto-verso halftone print is modeled as a diffusing substrate surrounded by two inked interfaces in contact with air (or with another medium). The interaction of light with the print comprises three components: (a) the attenuation of the incident light penetrating the print across the inked interface, (b) the internal reflectance and internal transmittance that accounts for the substrate's intrinsic reflectance and transmittance and for the multiple Fresnel internal reflections at the inked interfaces, and (c) the attenuation of light exiting the print across the inked interfaces. Both the classical Williams-Clapper and Clapper-Yule spectral prediction models are special cases of the proposed recto-verso reflectance and transmittance model. We also extend the Kubelka-Munk model to predict the reflectance and transmittance of recto-verso halftone prints. The extended Kubelka-Munk model is compatible with the proposed recto-verso reflectance and transmittance model. In the case of a homogeneous substrate, the recto-verso model's internal reflectance and transmittance can be expressed as a function Kubelka-Munk's scattering and absorption parameters, or the Kubelka-Munk's scattering and absorption parameters can be inferred from the recto-verso model's internal reflectance and transmittance, deduced from spectral measurements. The proposed model offers new perspectives both for spectral transmission and reflection predictions and for characterizing the properties of printed diffuse substrates. 相似文献
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The transmittance spectrum of halftone prints on paper is predicted thanks to a model inspired by the Yule-Nielsen modified spectral Neugebauer model used for reflectance predictions. This model is well adapted for strongly scattering printing supports and applicable to recto-verso prints. Model parameters are obtained by a few transmittance measurements of calibration patches printed on one side of the paper. The model was verified with recto-verso specimens printed by inkjet with classical and custom inks, at different halftone frequencies and on various types of paper. Predictions are as accurate as those obtained with a previously developed reflectance and transmittance prediction model relying on the multiple reflections of light between the paper and the print-air interfaces. Optimal n values are smaller in transmission mode compared with the reflection model. This indicates a smaller amount of lateral light propagation in the transmission mode. 相似文献
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Yang L Lenz R Kruse B 《Journal of the Optical Society of America. A, Optics, image science, and vision》2001,18(2):360-366
Light scattering, or the so-called Yule-Nielsen effect, and ink penetration into the substrate paper play important roles in tone reproduction. We develop a framework in which the influences of both of these effects on the reflectance and tristimulus values of a halftone sample are investigated. The properties of the paper and the ink and their bilateral interaction can be parameterized by the reflectance Rp(o) of the substrate paper, the transmittance Ti of the ink layer, the parameter gamma describing the ink penetration, and p describing the Yule-Nielsen effect. We derive explicit expressions that relate the reflectance of the ink dots (Ri), the paper (Rp) and the halftone image (R) as functions of these parameters. We also describe the optical dot gain as a function of these parameters. We further demonstrate that ink penetration leads to a decrease in optical dot gain and that scattering in the paper results in the printed image's being viewed as more saturated in color. 相似文献
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通过经典的Clapper-Yule模型的应用,对已有的点对点的半色调印刷品进行扩展,在忽略油墨渗透的条件下,建立起能具有打底油墨的半色调印刷品的呈色规律的理论模型.在假定油墨是非散射介质以及油墨的折射率与纸张的折射率近似相等的近似下,利用光在油墨与纸张中散射迁移路径长短不同的分程理论,建立了具有打底油墨的半色调图像的分程Clapper-Yule光谱反射率模型. 相似文献
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利用Kodak的Approval打样系统测试了13种印刷常用纸张,总结了纸张底色对印刷色彩的影响,并比较了校正纸张底色的3种色度转换方法:不同测量衬垫的色度转换方法、相对色度转换方法和基于测量数据的多项式转换方法。分析比较发现:如果印刷中使用理想黑,则不同测量衬垫的色度转换方法与相对色度转换方法是等效的;印刷色彩由于纸张底色差异所引起的色彩偏差,并非完全符合线性的转换关系,因此基于测量数据的多项式的色度转换方法的转换结果更加准确,特别是当2种纸张间底色的色差大于4ΔEa*b*时;由于多项式的转换需要使用所有复制色彩的测量数据,造成了实际应用中的诸多不便,因此ISO 13655标准中的不同测量衬垫的色度转换方法较适用于纸张底色偏差的校正。 相似文献
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准确预测印刷品的颜色一直是印刷复制中一个十分重要的课题。基于光能的辐射传递理论,通过分析光在油墨层表面及内部传播过程中的散射与吸收等规律,并引入荧光激发函数,对Kubelka-Munk模型预测印刷品时蓝紫波段反射率偏差的问题进行了修正,并建立了新的印刷品光谱反射预测模型。该模型可为计算机光谱配色和高精度仿真印刷系统的开发提供理论基础。 相似文献
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目的 研究包装容器对酒体品质的影响因素,为劲酒包装容器的选择提供科学的数据支撑。方法 采用光学透过率测试仪对不同包装容器的透光率进行了测定,并对贮存2年的劲酒的总黄酮含量、总皂苷含量、色率、淫羊藿苷含量、口感进行分析,数据分析的方法为随机区组设计资料的方差分析。结果 无色玻璃瓶、PET瓶透光率高达90%以上,深色瓶、涂漆瓶、陶瓷瓶、不锈钢瓶透光率均极小。总体来说高硼硅玻璃瓶和PET瓶储存的劲酒均有不同程度的颜色变浅,总黄酮、总皂苷含量降低,口感变差,其他容器储存的酒体之间没有明显差异,且它的总体品质要高于高硼硅玻璃瓶和PET瓶储存酒体的总体品质。结论 包装容器的透光性会对劲酒的品质产生影响,避光包装容器可能更适合劲酒的储存,避光容器的材质和形状对劲酒品质基本没有影响;对于透光性容器,容器形状可能影响劲酒品质,相较于圆柱型的包装容器,扁平型的可能更能保护劲酒品质。 相似文献