广告输出设备的颜色性能分析

围绕广告业彩色输出的硬件设备特性,通过建立的三维色域确定方法,探讨了常用广告输出设备颜色输出的物理能力。选择常用宽幅广告打印设备,针对广告色彩的常用输出模式,定量分析和比较了色域特征。结果表明,在广告行业中,针对一般的普通用户,目前市场上的Epson彩色喷绘设备具有相当的颜色输出效果;而对于高要求的专业级用户需求,则建议使用色域较大的喷绘设备,可获得一些黄、黄绿、绿,直至青颜色的高彩度色。     

如何为打印输出优化PS的设置

使用Photoshop提供的色域警告等功能预防打印输出时可能出现的问题。我们的电脑能使用不同浓度的红、绿、蓝三色混合出数以百万的颜色,而打印机只能使用青、品、黄、黑等油墨模拟出数量有限的色彩。屏幕上可以显示,而无法通过打印机输出的颜色,被称为"超出色域范围"的颜色。     

钴蓝影响硅酸锆发色的实验研究

针对钴蓝在不同添加量和不同细度对硅酸锆发色的影响进行实验,确定了添加量、细度与硅酸锆发色的关系。结果表明:钴蓝能显著改变硅酸锆的色调,使黄白色硅酸锆呈青白色,但却不能增加其白度,添加量过多反而会使亮度下降,影响白度;钴蓝细度的变化对硅酸锆发色无明显影响。添加微量的钴蓝可改变其色调,可拓宽硅酸锆的应用范围。     

陶瓷多通道喷墨印刷总墨量限制研究

针对陶瓷喷墨印刷多通道特性,设计陶瓷喷墨印刷总墨量限制测试色卡,喷印后通过视觉观察或测量法得到陶瓷喷墨印刷总墨量限制值,将此值应用于ICC制作过程,通过实验验证总墨量限制的重要性及准确性。此研究为陶瓷喷墨打印输出设备总墨量限制值的设定提供了一种简便可行的方法,对辅助研究打印机的线性化及研发具有自主知识产权的喷墨印刷流程具有指导意义。     

均匀色空间下红宝石颜色定量分级

采用国际照明委员会推荐的CIE1976均匀色空间,以CIELCH为表色系,采用X-rite i5测色仪量化红宝石的颜色指数.通过实验得到红宝石样品的颜色参数:色调角ho、饱和度C*、明度L.在标准光源下,将红宝石色调分为红色,粉红和紫红三个系列;饱和度分为灰、浅、中、浓、鲜艳五个级别;亮度分为暗、较暗、中等、较亮和亮五个级别.并综合颜色三要素,将红宝石颜色分为Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ、Ⅶ、Ⅷ八个级别.     

承德磷矿生产黄色磷酸二铵的方法

采用承德磷矿生产湿法磷酸。对磷酸二铵本色产品进行了研究,找出了承德磷矿影响产品颜色的主要因素。对比不同磷酸含铁量对料浆颜色的影响,找出了一种X试剂让磷铵料浆变浅,为着色黄色磷酸二铵创造条件。确定了X试剂加入点、加入量、及加入不同量黄色着色剂,对产品颜色的影响,找出了X试剂与黄色着色剂的最佳用量。     

洗涤剂中护色剂对织物护色效果的探讨

通过对比在一定洗涤条件下白布和色布的色度变化,研究了不同类型的护色剂在洗涤过程中的护色和防串色效果。结果表明：HP66加入量为0.3%时,可满足对白布的防串色效果;NaCl加入量为3%,对于色布的护色效果最佳。     

绿松石呈色机理实验与论证

矿物的成分、结构和键型是复杂的,引起矿物颜色变化的因素也是复杂的,一种矿物的颜色往往是多种呈色机制的总效应.绿松石是一种自色玉石,即它的颜色是由自身的成分和结构决定的.颜色正是决定绿松石经济价值的重要因素,长期以来,对绿松石颜色的研究一直是绿松石宝石学研究的重要内容.绿松石的颜色主要由Cu2 ,Fe3 离子决定,Cu2 离子对绿松石的基色--天蓝色起有益作用,而Fe3 则起相反作用,两者含量多少决定了色调的变化特点.这与用晶体场理论和光谱实验观测解释的呈色机制是一致的.     

数字输出设备线条输出质量测评

为了研究数字输出设备线条的输出质量,设计制作黄、品、青、黑4色不同宽度的横、竖线条测试图样,在两台彩色喷墨打印机上进行彩喷纸和光泽照片纸的打印输出.对输出测试图样的线条属性进行了客观属性指标的测量.测试结果表明：输出的线条宽度总比设计的宽度大;线条的边缘粗糙度与线条的方向相关,竖线条的粗糙度较横线条的大;输出线条边缘的模糊度主要受色墨和纸张的相互作用影响,具有涂层的纸张往往会加剧纸张表面方向的色料扩散,从而增强了线边缘的模糊性.     

基于EFI Colorproof系统的数码打样总墨量限定

以总墨量为数码打样流程的研究对象,通过数码打样机的基础线性化调整总墨量限定,分析了基于EFI Colorproof打样系统输出样张色彩密度及色差与总墨量的关系,得出了总墨量限定的原则,为数码打样总墨量的设定及软件开发提供理论依据。     

Color reproduction of authenticable luminescent backlit transmissive color images

We propose a method for creating authenticable color images under UV excitation backlight by printing an invisible luminescent white emissive ink layer on the verso side of a transmissive substrate and a classical cmy image on the recto side of the substrate. In order to obtain a backlit image whose colors are as close as possible to the original image colors, we map the input image sRGB color gamut into the gamut formed by the emissive white source attenuated by the classical ink halftones. The relationship between surface coverages of the classical cmy ink halftones and the resulting backlit colors is obtained by accounting for the transmission of the emissive white through the paper substrate and through the classical cmy ink halftones. The transmittance of the classical ink halftones is modeled by a new halftone absorbance prediction model. The lightness range of the luminescent backlit color gamut is expanded by printing a black and white UV‐absorbing instance of the original color image in superposition with the luminescent white emissive layer and in registration with the cmy image printed on the recto side. Luminescent backlit color images provide a high anticounterfeiting security, as they combine a verso printed invisible luminescent ink layer, a verso printed black and white instance of the original image and a matching recto printed cmy instance of the original image. The resulting luminescent backlit image colors are close to the original image colors only when observed in transmission mode under UV light. © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 331–340, 2014     

Evaluation of expanded gamut software solutions for spot color reproduction

Expanded gamut printing is an approach in color reproduction that expands the color gamut of conventional CMYK printing processes via the use of additional colorants, such as Orange, Green, and Violet inks. This study evaluates the ability of commercial color management software to create an accurate solution for an expanded gamut printing system. In this study, two printing processes were used, an Epson SureColor P9000 inkjet printer/proofer and an HP Indigo 7900 digital production press, both with 7-color expanded gamut ink sets. Software solutions from Alwan, CGS ORIS, ColorLogic, GMG Color, Heidelberg, and Kodak were evaluated. The systems were tested to see how well they could reproduce the colors in the entire PANTONE+ Solid Coated spot color library. It is shown that the solutions are able to reproduce 89% to 94% of the spot colors on the Epson P9000 inkjet printer and 77% to 87% of the library on the Indigo 7900, both to less than two CIEDE2000 (a typical tolerance in label and packaging work). The number of color patches in expanded gamut characterization test charts was noted, as this is still an area of proprietary, nonstandardized working practice. There are many different colorant combinations that can make the same color in expanded gamut printing. The ink build created by the different software solutions was studied, as it relates to press stability through appropriate choice of colorants. Pantone and Adobe provide everyday commercial tools for expanded color workflows. The study identified some issues with products from these companies that could confuse a less-skilled user in a busy production environment. The conclusion of the study is that expanded gamut solutions for spot color printing produce totally acceptable results for digital printing processes; expanded gamut printing is ready, here and now. The findings show that expanded gamut printing can replace cumbersome conventional spot color workflows creating considerable savings and advantages, especially for label and packaging printers.     

Let's call it “color‐gamut rendering”

The term “color gamut” historically has been associated with color output such as optimal color stimuli and additive and subtractive imaging systems. Recently, this term has been used with input devices such as scanners and digital cameras. It is proposed that the term “color‐gamut rendering” should be used instead of input devices. This clarifies the distinction between input (analysis) and output (synthesis) color systems in terms of the effect of an input system on defining the colorimetric properties of an output system. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 334–335, 2007     

数字中间片后期制作中的色彩管理

在色彩管理中使用LUT具有相当大的潜在应用价值。LUT是一个简单的数据结构,它把每一个输入值映射到相应的输出值,并且还可以确定视频硬件里每帧图像中每一个像素的数据值的大小。模仿和校正LUTs提供的转换,不但能保证多种显示器之间的匹配,而且在后期制作过程中还可以使显示的图像与胶片完美的匹配。介质中呈现的色彩组叫做色彩范围。电影正片的色彩范围与数字显示器的色彩范围具有不同的特性。数字中间片(DI)工艺有2种不同的图像编码方法:一种是使用DPX文件,其作用是进行输入和输出及表示底片密度,预览画面则需要显示LUT;另一种方法是不使用LUT而直接显示图像数据。图像数据显示的是显示器的色彩范围,而不是胶片的色彩范围。在记录到胶片上之前,数据需要转换成密度值。在制作DI过程中,可以模仿洗片厂配光工序,通过调节印片光号进行的色彩校正。本文从8个方面较详细的叙述了制作数字中间片时的色彩管理。     

Try camera gamut again: Not for size,but for camera and profile evaluation

Hunt and Pointer call into question the utility of the camera color gamut (at least by my definition). Such doubt may be partly due to the connection of gamut with a size metric. Quite apart from gamut size, the sets that define my gamut definition are essential to the evaluation of digital cameras in conjunction with their profiles. The output‐device gamut; emphasized by Hunt and Pointer is also important, but appears at another stage of color management. © 2007 Wiley Periodicals, Inc. Col Res Appl, 33, 82–83, 2008     

Spectral color management using interim connection spaces based on spectral decomposition

A feasible approach to spectral color management was previously defined to include lookups performed within an interim connection space (ICS). ICS is relatively low in dimensions and is situated between a high‐dimensional spectral profile connection space and output units. The definition of ICS axes and the minimum number of ICS dimensions are explored here by considering the LabPQR, an ICS described in earlier research. LabPQR has three colorimetric dimensions (CIE L*a*b*) and additional dimensions to describe a metameric black (PQR). Several versions of LabPQR are explored. One type defines PQR axes based on metameric blacks generated from Cohen and Kappauf's spectral decomposition. The second type is constructed in an unconstrained way where metameric blacks are statistically derived based on the spectral characteristics of the target output device. For a six‐dimensional LabPQR, one that uses three colorimetric and three metameric black dimensions, it was found that Cohen and Kappauf‐based LabPQR was inferior for estimating the spectra when compared with the unconstrained method. However, when the limited spectral gamut of an output device was introduced through printer simulation and necessary spectral gamut mapping, the disadvantage of the six‐dimensional Cohen and Kappauf‐based LabPQR dissipated. On the other hand, reducing LabPQR to only five‐dimensions (two metameric black dimensions) reintroduced the advantage of the unconstrained approach even after simulated printing including spectral gamut mapping. Importantly, it was found that the five‐dimensional unconstrained approach achieved equivalent levels of performance to a full 31‐dimensional approach within simulated printer spectral gamut limitations. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 282–299, 2008.     

Comparison of color gamuts among several types of paper with the same printing technology

In this work, we have studied the relationship among the colorimetric properties of different types of paper, having different finishing and grammage. Their color reproduction capability has also been analyzed by using the same printing technology (inkjet printing). On the one hand, we have plotted CIELAB data under the illuminant D50 into constant lightness and hue‐angle planes to be compared with MacAdam limits and with Pointer's real‐world surface color. On the other hand, we have calculated the volume gamut of the color solid associated to each color paper gamut. Analyzing the results, we have checked that there is not any clear relationship among the colorimetric properties of paper (for instance, CIE whiteness index, etc.) and the color gamut volume associated. However, the colorimetric parameters associated to the printed sample showed a quite good linear correlation between the minimum lightness (or the maximum blackness value) of the printed color chart and the color gamut volume. In particular, the greatest color gamut volume corresponds to the glossy papers taking into account this correlation for inkjet printing. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 330–336, 2009     

不同纸张对数字输出阶调特性的影响

为了了解不同纸张对数字输出阶调特性的影响,采用CorelDraw软件制作单色色阶测试版,选择常用的普通打印纸、一般照片纸和光泽照片纸在Epson Stylus Photo R250彩色喷墨打印机上进行输出,用DS分光光度仪对输出色阶进行CIEL*a*b*色度值的测量,用色彩管理软件为不同纸张制作特性文件,对不同纸张所能达到的数字输出阶调特性进行定量分析。针对选用的纸张进行测量后得出结论,输出色彩丰富的图像优选的纸张应是光泽照片纸,输出灰度层次丰富的图像可以选择普通打印纸。     

喷墨打印用黑色染料墨水在微孔型相纸上的耐臭氧性研究

研究了黑色染料墨水在微孔型相纸上的耐臭氧性,对现在行业里常用的黑色染料和本论文新采用的染料利用相同的配方体系进行了平行对比,在微孔型相纸上打印黑色的色块,放到臭氧老化箱里进行不同时间的老化后,测试色相及色密度的变化,发现本文新采用的染料用特定的配方具有明显高的耐臭氧性.