纸张墨斑性能检测方法研究初探

探讨了不同平滑度纸张的墨斑性能检测及评判方法。结果表明,4种墨斑测试方法能够较好地预测纸和纸板在实际印刷过程中的墨斑产生情况;主观判定采用成对比较法较为稳定可靠;通过与成对比较法的相关性分析,PTS分析软件采用的光谱法能够较客观地定量评价墨斑。     

喷墨打印纸印刷适性预测模型的研究

测试了不同喷墨打印纸的白度(x2)、光泽度(x3)、粗糙度(x4)、透气度(X5)、吸水性(x6);在相同条件下打印喷墨打印纸,测量各印刷品的质量参数:色密度(D)、印刷网点扩大(DG)、印刷反差(K)、色调误差(H).再利用SPSS主成分分析法,将印刷品每项质量参数与喷墨打印纸性能参数结合分析,可得印刷品单一质量参数与喷墨打印纸性能的相关性函数D/DG/K/H(x2,x3,x4,x5,x6);同时,对质量参数综合处理后,可得印刷品质量评价的综合模型Y=0.479D -0.491DG +0.527K -0.501H.经验证,该模型不仅可用来分析影响印刷品质量参数的喷墨打印纸性能参数的权重,还可用来判断和预测印刷品的综合质量,可较好地预测喷墨打印纸的印刷适性.     

欧洲印刷品脱墨性能调查

为建立欧洲印刷品回收能力的数据库,对欧洲213种印刷品的脱墨性能进行了评价。主要是新闻纸、杂志纸,也包括一些传单、目录及电话簿纸。按照INGEDE方法11进行脱墨试验,结果按照脱墨性能计分法加以评定。发现报纸有27％不适于脱墨,其中苯胺印刷和喷墨印刷的7种报纸均未能通过测试。南欧和北欧分别有50％和38％的报纸未达到脱墨要求。杂志纸一般具有较好的脱墨性能。传单纸几乎有40％不适于脱墨。未涂布传单纸均未达到脱墨要求,涂布传单纸的脱墨性能相对较好。涂布目录纸的脱墨效果较好。电话簿纸很难脱墨,有57％没有完全达到脱墨要求。     

基于傅里叶变换和梯度法构建纸张匀度评价模型

采用傅里叶变换滤波和梯度分析法构建了纸张匀度分析的数学模型,在梯度分析中,为了提高运算速率,采用Roberts算子替代微分。并将该方法与国际上通用的标准匀度指数模型及人眼视觉评价方法进行对比分析。结果表明,该方法思路简单、运算速度快,有效地去除了噪音,既反映了纸张局部定量的微弱变化,又反映了整体定量的变化情况,与标准匀度指数和人眼视觉评价结果有很好的相关性。     

喷墨印刷的方式及原理

正喷墨印刷是一种新的不用印版的印刷方法,它通过特殊装置,在电子计算机控制下,由喷嘴中压电晶体发电脉冲,将油墨挤出并向承印物如纸张的表面喷射雾状墨滴,根据电荷效应在印刷品表面喷射雾状墨滴,在印刷品基表面直接成像。     

印刷墨斑的类型及测定方法

<正>一、印刷墨斑的定义及分类印刷墨斑是指在印品表面形成的颜色不正常、深浅不均匀的斑点或条纹。墨斑一般在文字印刷中见不到,在印刷较厚重的图案中也难发现,而在颜色均匀的实地区域、阶调较为平缓的区域或其他色调均匀的背景中较为明显。     

可食性喷墨油墨性能对印刷品质量的影响

可食性喷墨油墨为水性油墨,绿色环保,其原料全部符合食品卫生标准,可以用喷墨印刷的方式直接在食品、药品或产品的包装表面印刷,具有色彩鲜艳、无毒、无污染的特点。采用在油墨中添加不同含量的染料、树脂及表面活性剂的方法,改变油墨的黏度和表面张力,探讨不同性能的可食性喷墨油墨对印刷品质量的影响。采用CCD图像检测分析系统,对印刷品的线条质量、实地填充质量及圆点质量进行评价和分析;用密度计测量印品的色密度并进行颜色评价。结果表明,可食性喷墨油墨的黏度和表面张力影响印刷品的质量,通过调整树脂及表面活性剂用量,可以获得适于喷墨印刷的可食性喷墨油墨。     

基于CCD获取测控元素评价喷墨打印质量

随着数字印刷以指数级的速度猛增,数字印刷质量检测的方法和标准也成为研究的热点。本文的主要工作和创新点包括:①首次将计算机图像分析法引入喷墨印刷质量检测中;②通过与传统印刷质量检测进行对比,确定了将墨点、线条、色块和MTF(Modulation Transfer Function)等作为基本测控元素,并设计出用于评价喷墨印刷质量的测试样张;③提出了针对各测控元素的检测算法和总体检测流程,实现了对喷墨印刷质量的检测,并通过实验对检测方案的准确性进行了验证。实验结果证明,基于CCD获取测控元素法可以较为准确地实现对喷墨印刷质量的客观评价。本文的研究完善了印刷品的检测体系,可以推广作为印刷企业针对喷墨印刷品质量检测的标准方法。     

数字喷墨印刷品光老化现象研究

数字喷墨印刷凭借高质量、低成本、易操作的优势,应用领域不断扩展,被认为是未来数字印刷技术发展的重要代表。随着数字印刷与网络出版技术的发展与结合,数子喷墨印刷方式被逐渐应用于图书出版行业的个性化按需印刷,这使得纸质喷墨印刷品的存置稳定性研究备受关注。本文是针对纸质喷墨印刷品自然条件下光老化现象进行的研究,文中首先分析了导致印刷品褪色的主要因素,提出了对印刷品老化现象进行分析的方法,以及对影响因素进行分离的算法模型;其后,在排除湿度变化影响的完全自然光照射条件下,对数字喷墨印刷样张进行了光老化试验,通过X-rite Spctroeye密度仪测量晒前、晒后实验样张的相关参数,分析了光照后印刷品颜色变化现象,并进一步采用曲线拟合的方法,得到了油墨光照衰退经验模型;最后,对印刷材料光老化特性对印刷品色彩及阶调的影响进行了分析与总结。本研究是首次在尽量排除湿度变化影响的自然光照条件下,对数字喷墨印刷品进行的光老化试验,并对图像阶调递增过程中油墨光照衰退的规律进行了推导,总结得到了油墨光照衰退经验模型。本文所提出的光老化分析方法与得到的油墨褪色关系模型,对印刷品老化现象的后续研究具有重要参考价值。     

透过Drupa领略喷墨印刷风采

文章重点介绍了Drupa2008上的几款喷墨印刷设备,并就喷墨印刷技术的应用领域及发展前景进行了初步的探讨.喷墨印刷(ink-jet printing)是一种无接触,无压力.无印版的印刷技术.其工作原理是先将电子计算机存储的图文信息输入喷墨印刷机.再通过特殊的装置.在电子计算机的控制下,由喷嘴向承印物表面喷射雾状墨滴.根据电荷效应在承印物表面直接成像.得到最终的印刷品.     

纸张转印墨斑检测方法初探

利用IGT印刷适性仪,在不同印刷条件下探讨了新闻纸、单面涂布白纸板和铜版纸转印墨斑的变化规律.结果表明,两种新闻纸的优化印刷条件为:油墨量0.10 mL、印刷压力650 N、速度0.4 m/s;主客观判定结果有差异,最少墨量时客观判定效果好,中等墨量时主观判定效果较好.两种涂布白纸板的优化印刷条件为:油墨量0.35mL、印刷压力200 N、速度0.3 m/s;铜版纸优选出的印刷条件为:油墨量0.50 mL,印刷压力500 N,速度0.2m/s.2人组及4人组主观判定结果的相关性较强;3种客观判定方法中,光谱法与主观判定的一致性最好,PTS法次之,灰度法最差,光谱法和PTS法有望作为评价纸张转印墨斑的新方法.     

基于色域划分的多通道喷墨打印系统分色模型研究

随着颜色复制精度的提高,含有浅色墨的多通道喷墨打印系统使用范围越来越广,但是含浅色墨的喷墨打印系统墨色维度高,光谱冗余严重,分色数据量较大、灵活性不高,且由于同色油墨间的相关性,映射精度对分色精度影响较大。针对这些问题,本研究在色域划分思想的基础上,基于分区纽介堡方程理论,结合灰成分替代原理以及两种色墨替代原理,建立了CMYKcmk两种色墨喷墨打印系统的分色计算模型。结果表明本方法能够减少分色计算量,提高分色可调整性,较好地实现两种色墨喷墨打印分色。     

Print clarity on digitally printed textiles – a quantitative evaluation

Abstract

Print clarity of a digitally printed product has great impact on the final esthetic appearance and performance of the printed products. Print clarity on various textile substrates is considered as image sharpness in this research. The current standard test method is a subjective test where a printed fabric is evaluated visually by one or more human subjects. To advance digital printing of textiles further, it is critical to create a quantitative evaluation method for testing print clarity (sharpness), as has been done with paper. In this paper, a quantitative evaluation of the print clarity (sharpness) of a digitally printed test pattern on textiles was created. Different colors, directions, and fabrics (substrates) were considered in the design of experiment. Eight similar weight and structure woven polyester samples along with a paper substrate were printed with MS JP7 printers using nano-pigments and printed in two directions. The resulting prints were scanned with an EPSON Expression 11000XL Photo Scanner. Several software packages, including Image-Pro and MatLab, were used to process data to analyze and compare image contrast of the test pattern under different conditions. Improved print clarity in digital printing on polyester woven fabric was explored. The newly developed test method is a quantitative test method that makes optimization of the print quality (sharpness) easier and more accurate.     

Fabric wrinkling evaluation: a method developed using digital image analysis

The textile and clothing industry has conventionally used subjective methods for the assessment of fabric wrinkling. Indeed, the fabrics were usually evaluated subjectively in reference to a set of visual standards. However, the visual assessments of the wrinkling degree, often showing inconsistencies between wrinkle judgments of observers, are severely influenced by the color and the fabric texture which may exist. In this paper, an objective method which permits an evaluation of multidirectional wrinkling of any colored fabric has been developed using digital image analysis. This method consists in capturing images of the color wrinkled fabrics and processing them in simple steps using image‐processing software. The surface roughness, density, width, length, number, and height of the wrinkles, considered as wrinkling characteristics, were extracted. Wrinkle degree was selected to use as the comparative parameter of the result evaluation from conventional and digital methods. The wrinkle grade of each fabric sample obtained through the conventional technique was statistically compared with that obtained through the digital technique developed. This study demonstrates that the results of the digital method developed for wrinkle evaluation of colored fabrics were similar to those of conventional methods of wrinkling evaluation.     

Objective evaluation of multidirectional fabric wrinkling using image analysis

In the textile industry, the wrinkled fabrics are regularly evaluated subjectively in reference to a set of visual standards. However, due to the disadvantages of visual evaluation, which are unreliable and time-inefficient, several objective methods were recently developed. In this paper, a new objective evaluation of multidirectional realistic fabric's wrinkling generated by the French method of “cylindre creux” was proposed using the image processing. Four characteristics of wrinkled fabrics were evaluated to estimate wrinkle grade with a statistical model. The study reveals a good correlation between the objective wrinkling evaluation (using image analysis) and the subjective evaluation (using the visual standards).     

基于图像处理和BP网络的烟包印刷质量检测

为解决烟包印刷质量在线检测问题,本文提出了一种基于图像处理和BP神经网络的印刷质量检测和诊断方法.利用待测印刷图像和标准模版图像间差异的特征参数,BP神经网络可将印刷品分成优秀、合格以及不合格三类.实验结果表明,现有系统能够满足烟包印刷质量检测的需求,并且能够运用于烟包印刷质量的在线检测中.     

图像处理技术在服装褶皱评价中的应用

对图像处理技术在纺织服装领域的应用成果进行了回顾,在此基础上探讨了该技术在服装表面褶皱评价领域的应用基础和原理。分析了服装褶皱的形成方法和穿着后所产生的视觉效果,提出了从服装表面提取褶皱图像的方法。经过对图像的处理提取了以灰度为基础的评价指标体系,提出了褶皱数、褶皱深度、褶皱宽度和褶皱不匀度等服装褶皱的评价指标,以期对服装表面褶皱这一视觉效果进行数字化描述。研究结果表明这些评价指标能够很好地反映服装表面褶皱的形态特征。     

The effect of weave structure on the quality of inkjet polyester printing

In this study, the print quality of lines were investigated in warp and weft directions that were inkjet printed on various weave structures of polyester such as plain, 2/2 twill, 3/1 twill, 3/2 twill and 4/1 twill. In order to study the effect of weave structure on the quality of inkjet printing on polyester fabrics, lines having a width of 1?mm, 2?mm, and 4?mm were inkjet-printed and the print quality was measured as the line width. The quantitative analysis of lines width was performed by scanning the fabrics with a scanner. The obtained result showed that the weave structure is effective on the lines width and print quality, and the plain weave structure had the worst print quality in both directions. Also, the width of lines printed in the weft direction was more than lines printed in the warp direction which is possibly due to more density of warp than weft. The effect of weave structure and print direction on lines width and print quality was also confirmed by the analysis of variance (ANOVA) results. The image processing was shown that the ink spreading shape on the various fabrics is different and is affected by the weave structure and the print direction.     

喷墨印刷网点扩大补偿研究

在不同纸张上以密度补偿方法为基础,以纸张、印刷品光谱反射率和印刷反差为依据,结合网点扩大补偿控制获得最佳的再现原稿的印刷品。密度补偿方式可以使较低级的表面施胶喷墨用纸也能获得较优的图像质量,满足人们在视觉效果上对原稿层次再现的各种要求,从而降低印刷的纸张成本。     

基于高维多元数据的酒体感官评价可视分析

酒体质量评价以感官鉴定为主,但感官评价易受人的身体条件和经验等因素的影响。为提高评价的稳定性和有效性,建立以理化指标数据为依据的评价方法。本文提出了一种基于大数据可视分析的研究方法,挖掘高维多元指标数据对酒体感官特性的影响。首先,对高维多元指标数据的相关性,以及与感官评价的相关性进行分析,通过图模型阐释关系特性,初步建立面向领域的可视分析方法。然后,采用基于机器学习的数据分析技术,结合感官评价构建酒体质量评价模型。最后,结合评价模型对酒体指标参数的重要性进行分析。在此基础上,对模型的评价效果进行了验证,分别选取两类样本进行对比,一类样本包含重要性得分较高的6 项理化指标,包括酒体密度、残糖、挥发性酸、酒精度、硫酸酯和非挥发性酸,另一类样本包含全部11 项理化指标,验证结果显示两类样本的预测结果相近,分类预测误差仅相差0.4%,表明以上6项理化指标是影响感官评价的主要成分。该可视分析方法可降低理化指标的维数,并保留酒体质量的特征信息,用于酒体质量的评价,对酒体质量科学化评价起到重要作用。