【作者】 张琳；

【导师】 张美云；

【作者基本信息】 陕西科技大学 ， 制浆造纸工程， 2013， 博士

【摘要】 目前，全球造纸工业的大宗消费领域是印刷行业，纸张成本占到印刷总成本的60％～70％，纸张印刷适性是决定其印刷过程和质量的重要因素。揭示纸张性能与印刷品质量之间的作用机理是造纸和印刷行业尤为突出的问题。然而，由于“纸张性能–印刷”之间复杂的多元关系以及影响因素的不确定性，该技术难题尚未能较好突破。本课题以不同印刷适性纸张为分析对象，评判纸张相关性能对其响应印效指标的影响程度，量化两体系之间的多元非线性作用规律；从纸张相关性能有效组合角度出发，研究纸张印刷适性的综合质量评价模型；推导纸张性能综合和印刷品质量综合的数学表达式，探索两者的关联，构建纸张印刷适性的预测方程；基于光谱传输特性，实现测试纸张与参考纸张之间的印刷适性匹配和评估，并推导待印刷纸张的光谱表征模型；创建自定义的纸张特性文件，揭示不同印刷适性纸张与目标印品阶调、色彩传输的作用机理，并开发其应用模块；针对色域边界、色域映射、再现意图三个色彩复制关键技术，分别提出新的算法，并研究根据不同印刷适性纸张的复制特征，自动选择适合应用策略机制，且编制软件程序。本课题量化了纸张在印刷中的行为和作用规律，旨在为纸张匹配适宜印刷条件提供科学依据，形成纸张应用与印刷实践控制的系统理论指导，推动我国造纸与印刷技术的高质量生产和针对性应用。利用灰关联分析，研究纸张相关性能对印刷品质量的影响程度，将各性能进行综合排序。结果表明，铜版纸性能影响力从大到小依次为：平滑度、匀度指数、光泽度、白度、吸墨性、表面强度、不透明度；胶版纸依次为：吸墨性、匀度指数、光泽度、白度、不透明度、表面强度、平滑度；轻涂纸依次为：平滑度、吸墨性、白度、匀度指数、光泽度、不透明度、表面强度。继而选择影响程度最大的前三个纸张性能作为自变量，以响应的印品质量指标为因变量，建立两者之间作用规律的多元非线性回归模型，以此可以寻求最佳纸张性能组合，获得预期印刷效果。将纸张相关性能指标有效组合可以对纸张质量进行更准确的判断。选取6个纸张性能作为输入层，纸张综合评价级别值作为输出值，构建纸张RBF神经网络综合评价模型。结果表明，该模型符合实践应用，且精度比BP神经网络更高，但纸张评价值范围仅为1、2、3。为了进行更细致的比较，提出基于人工鱼群–投影寻踪算法的纸张质量综合分析模型，建立纸张评价等级与投影值之间的关系式，计算出的纸张评价值范围可为任意实数，可比性更高，尤其适合于同等级纸张的比较。利用主成分分析法，分别得到纸张性能综合和印刷品质量综合的计算表达式，然后以具体纸张性能综合值为自变量，以印品质量综合值为因变量，拟合两体系之间的关系曲线，最终得出纸张印刷适性的预测方程，其自变量通过纸张性能综合表达式被转换成纸张相关性能。该方案将纸张和印刷结合起来，获取信息更全面，应用方便，结果客观具体。基于光谱传输特性，提出四种方案实现测试纸张与参考纸张之间的印刷适性评估，包括朗伯-比尔光谱定律、Kubelka-Munk光谱模型、纽介堡光谱方程、主成分分析法。结果表明，主成分分析法光谱评估效果最好，但计算量最复杂；纽介堡光谱方程评估效果和计算量均次之；朗伯-比尔光谱定律和Kubelka-Munk光谱模型评估效果最差，但计算量最小。进一步将高品质的纸张视为朗伯六界面体，分解为三个部分再进行组合，推导出纸张的全反射率-全透射率新模型，使得在各种测量几何条件下，表征纸张的光谱特性更简单、直接。提出并建立自定义的纸张特性文件，使印刷所用的纸张和油墨能更好地相适应和匹配。纸张特性文件的核心建立步骤是：印刷设备的基本线性化；最适合油墨色彩数量的判定；判断最大油墨厚度并给出油墨量建议。利用VC++软件进行上述步骤编程使其能够在色彩管理系统中进行调用，应用于实际印刷系统中。利用曲面细分技术计算色域球体边界的三角形近似值，将凸壳算法非空区域最大值点的γ=0.2，提出基于分区最大边界法和凸壳算法的组合方案色域边界新算法。结果表明，组合算法精度和计算量均介于分区最大边界法和凸壳算法之间。基于遗传算法，提出色域映射的新方法，将图像超色域颜色的CIELAB色彩空间坐标定义为基因，适应度函数定义为原始图像和映射图像的S-CIELAB色差的倒数，实行单点交叉或多点交叉。结果表明，遗传算法色域映射方案比传统裁切算法的色差要小。针对四种再现意图，对其各自特点及适用范围进行实验和规律总结。最后，分析纸张各性能与再现意图、色域边界算法及色域映射方法的关系，研究得出根据纸张相关性能，自动选择各种色彩具体算法的规律和方案流程，并利用VC++软件实现自动选择功能。更多还原

【Abstract】 At present, the maximum concentration of consumers for the pulping andpapermaking industry is the printing and packaging industry. The cost of paperaccounts for60%~70%of the total cost for printing. Paper printability is thefirst factor to determine the printing process and quality. Therefore, revealingand predicting the mechanism and the effect of paper printability is a particularlyprominent and important task for both the papermaking and the printing andpackaging field. However, due to the complex multiple correlations anduncertain influence factors of "paper-printing", the technical problem has notbeen broken through.This subject focuses on the printability of different paper and analyzes thecorrelation between each paper performance and responsive printing effects.Then the multivariate nonlinear analytic expression is established. From the viewof synthesizing index, the mathematical model for comprehensive evaluation ofpaper printability is studied and provides quantitative and scientific judgmentreference for paper in the same or different level. From the connective view ofpaper and printing, the concepts of paper comprehensive index and printingquality comprehensive index are put forward respectively. The predictionmechanism and model of paper printability is discussed. Based on the spectralimaging technology, four kinds of schemes are used to realize the printing matchand evaluation between the reference paper and the test paper. And the totalreflection and transmission model of a high quality paper is characterizedspectrally as a lambert body. Then a special paper printability file and itsprogramming module are created. The roles and laws between paper printabilityand the target tone and color transmission are revealed. The three keytechnologies which are respectively color gamut boundary, color gamut mappingand rendering intentions are studied and the new algorithms for above are putforward. Then the correlation law of automatic selection and matching accordingto the different printing feature of paper printability is studied. This paper aims to provide a quantitative science criterion suitable for printing conditions for paperand form system theory guide for paper application and printing practice control.And it will promote high quality production and specific application fortechnology of papermaking and printing.Properties of paper printability are numerous and complex and therefore arestudies of correlation. Firstly the influences of the paper printability (includingsmoothness, ink absorption, gloss, whiteness, opacity, evenness index, surfacestrength) on the printing effects (including the C, M, Y, K solid printing density,designated printing image gamut volume and50%dot gain) are analyzed by greycorrelation analysis and sorted according to the correlation degree. And then thetop three influential factors are selected as the independent variables of themodel based on the multivariate nonlinear regression. Finally the approximatemodel between paper main performances and its responsive print effects isestablished. Results show that the approach can quantify the multiple complexnonlinear relationship between paper and printing effectively and clearly and thebest combination results of performances are got.We can make a correct evaluation on paper only when many paperperformances are synthesized. Based on the classification quality standard of artpaper which is summarized by myself, six main paper properties, includingsmoothness, gloss, whiteness, ink absorption, surface strength and opacity, areselected. Then by using the Radial Basis Function(RBF) neural network, with360groups of custom training samples as input of the network, with the papercomprehensive assessment level as the output of the network, the RBF neuralnetwork model for comprehensive evaluation of art paper quality is built. And250groups of the known quality grade art paper are used to test thecomprehensive model. Furthermore we use the BP neural network model forcomparison. Results show that the evaluation results for art paper quality basedon RBF neural network are more accurate and trustworthy than that of BP neuralnetwork. The evaluation model reduces the influence of subjective factors,simplifies the calculation steps and provides a new train of thought for thecomprehensive evaluation of paper quality. In order to sort the quality of paperfurther, the model of paper quality based on Artificial Fish Swarm-ProjectionPursuit algorithm is put forward. And15examples which each includes six indexes as the main parameters are selected as the training samples and9samples as testing samples. Research has shown that there is no subjectiveweights in the evaluation process and the result is a specific value. Therefore, theresearch program has the high comparability and more suitable for theassessment of the same grade paper.The combination of paper and printing for prediction of paper printability ismeaningful. The paper performances and the printing quality indexes arerespectively analyzed using Principal Component Analysis(PCA). The variancecontribution rates of principal components are used as the weights. Thecomprehensive evaluation of paper or printing can be got by the sum of linearweighting and it synthesizes paper performance and printing effect. Then theprinting comprehensive quality index are used as the dependent variables and thecomprehensive properties of paper as independent variables. Then therelationships between printing comprehensive quality and comprehensiveproperties of paper are discussed and the paper printability is forecast finally.The method provides a specific formula which is very convenient, quick andobjective for application once the parameters are determined.Paper properties based on spectral imaging technology are studied and fourkinds of schemes including Lambert Beer law, the Neugebauer equation,Kubelka Munk model equation and Principal Component Analysis are putforward to match and evaluate the relationship between the test paper and thereference paper. Results show that the project by PCA is the most complicated,but it is better to evaluate. The Neugebauer equation comes second. The methodsby Lambert Beer law and Kubelka Munk model are worse but a small amount ofcalculation. Furthermore paper is regarded as a six-interfaces body and brokendown into three sections. Then the new spectral model of paper reflectivity andtransmissivity is deduced by the combination of three sections above. Resultsshow that the characterization of the total reflection and the transmission of highquality and glossy paper (as a lambert body) is more simple and direct in avariety of measuring geometric conditions. In addition, the air-paper interfacehas been split which dissociates the measurement geometric-dependentparameters and the measurement geometric-independent parameters effectively.After inspection, the model can characterize and get the spectral characteristics of paper well.We put forward and set up the custom paper property file which makespaper and ink used adapt and match well. The detailed steps are built anddetermined for paper property file, including the basic linearization of printingequipments; the judgment of the color number suitable for ink most; therecommendation of the maximum ink thickness and ink volume. And the specificestablishment steps are programmed by relevant software so as to be invoked inthe color management system. Finally the paper property file is plugged into oneof the three modules in Window Color System. The research can be applied inprinting system well and serve for the actual printing production.The three color reproduction technologies which include color gamutboundary, gamut mapping and rendering intentions are studied respectively withproposing new algorithms. For the color gamut boundary algorithm, the newcombination scheme is proposed based on the Segment Maxima GamutBoundary Description(SMGBD) and convex hull algorithm used commonly.Analysis results show that the precision of convex hull algorithm is higher thanthat of SMGBD and the combination algorithm but the calculation process andthe actual use of SMGBD is better than the other two. The combinationalgorithm is in between. For the color gamut mapping, the color space is carriedout by the Genetic Algorithm. The results show that it is more advantageous thantraditional cutting algorithm. For rendering intentions, the characteristics andapplication range of four intentions are summarized by experiments. Finally, therelationships among paper performances, color gamut boundary algorithm,gamut mapping methods and rendering intentions are analyzed. Then theschemes and flows of automatic selection of color technology according to paperperformance are studied and the automatic selection functions are realized byVC++software.更多还原