Precise capture of colors in cultural heritage digitization

A workflow for the color reproduction of digital still images for the purpose of cultural heritage digitization is presented. An analysis was performed to determine the effect of RAW to TIFF transformation; RGB to CIE L*a*b* transformation; white balancing; use of standard color spaces: sRGB, AdobeRGB (1998), ProPhoto RGB, eciRGBv2; custom DCP, and ICC profiles assigning. For the analysis, Color Checker Classic and Digital Color Checker SG targets were used. The precision of the color reproduction was checked against FADGI and Metamorfoze standards. We demonstrate that to obtain high color fidelity reproduction, white balancing and a custom ICC profile are necessary, while DCP profiling could be omitted. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 333–336, 2017     

A comparative analysis of the characteristics and images of costume colors in the traditional plays of Korea,China, and Japan

The purpose of this study was to analyze quantitatively the characteristics and images of costume colors in the traditional plays of Korea, China, and Japan. The study focused on the Korean Masque, Beijing Opera, and Kabuki costume colors based on a selection of 1135 color samples. The collected source data were selected by extracting digital color data by using the Eyedropper Tool of Photoshop 7.0. The RGB color data were transformed to H V/C and the attributes of hue and tone were analyzed. Color images were analyzed with the color image scales of IRI Color Design Institute and Shigenobu Kobayashi to increase the validity of the evaluated images. As a result, the “five element colors (red, yellow, purple–blue (PB), white, and black)” from the theory of “Yin‐Yang Wu‐Xing” were used in the common stage costume colors of the Korean Masque, Beijing Opera, and Kabuki. Red, a preferred Asian color, was used most frequently in the costumes of these three traditional plays. A comparison of the traditional stage costume colors in the three northeast Asian countries revealed a difference in tones rather than in hues. First, the Korean Masque frequently used white in accordance with the tradition of white‐clad people and the cultural view of colors in which natural colors were preferred. Additionally, in the Masque, Koreans used colors based on the theory of Yin‐Yang Wu‐Xing with high‐chroma tones. On the other hand, the Beijing Opera exhibited the gorgeous and strong color images of China, by adopting high‐chroma colors in the Five Element Color: R, Y, PB, white, and black. Last, in the Kabuki costumes, a variety of white, black, dull, light, dark, strong, vivid, deep, bright, and grayish tones played an important role in showing various color images. The costume color images of the traditional plays of the three countries revealed that all shared the use of dynamic, springy/casual, and gorgeous images in the strong contrast of five element colors. Regarding the differences, the Korean Masque exhibited natural images in favor of natural colors, whereas the Kabuki displayed modern, decent/formal images by using dull, dark, and grayish colors. The study results suggested that the three countries commonly used five element colors from the theory of Yin‐Yang Wu‐Xing, but that their color images differed in terms of the tones used and the techniques for color combination. These results reflect that colors in the traditional costumes of the three countries are affected by their cultural codes, thereby representing the characteristics ofcertain peoples and cultural circles. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011     

A study on the application of an artificial neural algorithm in the color matching of Taiwanese cultural and creative commodities

In the recent years, great importance has been shown toward the cultural creativity in Taiwan. Cultural identification and determining how best to apply it to commercial products require investigating and compiling a vast amount of cultural information, along with the individual ideas of designers, to develop new cultural products. During the product development and design process, the color scheme is the final and most important element. It not only represents the first image of the product but also elicits the important first‐sight impression of consumers. Consequently, color ranks first in cultural commodity development. By understanding the Taiwanese culture, as well as assessing, verifying, and internalizing it into the materials that can be used by the designers, this study uses an artificial neural network system and simplifies the collected pictures that are representative of the Taiwanese culture into groups of different matching colors to assist designers in developing cultural commodities with different features and according to different cultural styles. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 341–351, 2015     

Impact of the adapted white point and the cultural background on memory color assessments

With their inherent ability of serving as an internal reference, memory colors provide a very powerful concept in the evaluation of color rendering properties of white light sources with respect to visual appreciation. Recent results for example suggest fairly good correlations between memory-based color quality metrics and the observers' general color preferences. However, due to technical limitations in the design of the underlying psychophysical experiments, they generally lack the explicit inclusion of realistic viewing and adaptation conditions, which is supposed to have a nonnegligible impact on the model prediction performance. In addition, intercultural effects might play a crucial role in the context of memory colors. For these reasons, the current article investigates the impact of both the adapted white point and the observers' cultural background on memory color assessments in order to contribute to a better understanding of these dependencies and their interactions. For this purpose, the color appearance rating results of Chinese and German observers were collected for a selection of 12 different familiar test objects assessed under two different adaptation conditions at 3200 K and 5600 K, respectively. From the statistical analysis of the experimental data, it is shown, in accordance to previous studies, that the impact of the observed intercultural deviations is likely to be of no practical importance even though significance is found. Despite considerably larger effect sizes, the same must be concluded for the two tested adaptation conditions.     

Perceived density,a further attribute of color,revealed by the colors favored in Japan

Colors can be characterized by three main attributes: hue, value, and saturation. But colors also exhibit other phenomenological qualities. In this study, we identify one such secondary attribute of color: perceived density. We discuss the prevalence of dense colors in Japan starting from the “48 Teas and 100 Mice” colors of the Edo period, and develop the concept of perceived density through this aspect of Japanese color preference. When vivid colors were forbidden to commoners during the Edo period, subtle variations of brownish and grayish colors were created. These colors with base tones were not salient, yet they looked dense. Muted colors with paradoxical richness are still common in Japan today. Japanese commodity design often uses muddy colors with white or gray undertones, and deep colors with black undertones. Together they form distinct groupings of relatively dense color. The perceived density of color corresponds to how dense and filled, or thin and airy a color appears. Colors of higher perceived density appear to be more packed and to have mass. Perceived density of color is unusual in that it does not have a monotonic relationship with one of the primary perceptual attributes. High apparent density is observed in a central region of an equi‐hue plane where value or saturation are at intermediate values. We consider two possible explanations of how high values of density can coincide with middling values of value and saturation: characteristics of the spectral reflectance curves, or the complexity of the neural signals that underlie the emergent property.     

Computational color analysis of paintings for different artists of the XVI and XVII centuries

We have performed a computational color analysis of images of paintings for six master painters: Titian, Rubens, El Greco, Velázquez, Rembrandt, and Vermeer. These painters show the evolution from the renaissance to the baroque style. Different first and second‐order statistical parameters have been obtained and analyzed in order to fix which of them can be common for the different artists and which of them can be representative of a certain period of time or the evolution of the art. The firsts include the orientation and semi‐axes ratio of the ellipses that define the gamut in the chromaticity diagram and the dependencies with the frequency of the power of the Fourier transforms. Most differences among artists can be found in the volume and area of the gamut, the number of discernible colors which is greater for Titian, El Greco and Rubens, compared to Velázquez, Rembrandt and Vermeer, the average value of L* and the number of dark pixels.     

从涂料角度看待敦煌壁画色标及变色问题

描述和评论了敦煌莫高窟壁画的色标及变色问题,并从涂料专业的角度对敦煌莫高窟壁画的保护和维修问题提出了看法。     

Effects of color on expectations of drug effects: A cross‐gender cross‐cultural study

To study the role of color in expectations of drug effects, 80 Chinese participants (40 females and 40 males) were asked to classify each of seven single colored capsules and six differently colored two‐piece capsules into one of four classifications of drug effects. The results from the Chinese sample were also compared with that from four other cultural groups studied elsewhere. The Chi‐square test results showed that all seven single colored capsules yielded non‐chance distributions in classifications of drug effects, with six showing specific effects; and that five two‐colored capsules had non‐chance distributions, with four significantly associated with specific effects. Notable gender differences were observed in the expectations of drug effects. While the cross‐group comparison revealed consistent red‐stimulant and blue‐depressant associations across the five cultural groups, disagreements existed for other colors among the groups. The findings emphasized the importance of color in drug design and administration in support of drug differentiation, medication adherence, and drug efficacy, and suggest gender and cultural implications on the basis of color to achieve better drug effects. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 124–130, 2017     

A general framework to study the price‐color relationship in paintings with an application to Mark Rothko rectangular series

We propose a general framework to study the relationship between the price of a painting and its color‐related attributes. To this end we focus on four key aspects: dominant colors, features of the color palette, color harmony, and color emotions. We demonstrate the usefulness of this approach with an example based on Mark Rothko's post‐1950 paintings (the “rectangular” series), and auction data from the 1994 to 2018 period. We identify two distinct price‐color regimes in Rothko's market: (a) [1994‐2005], a period in which prices are explained mainly by the growing popularity of the artist regardless of the color attributes of the paintings sold; and (b) [2006‐2018], a period in which color‐related attributes explain most of the prices. Furthermore, we find that in this second period, the dominant colors and the diversity of the color palette, are by far the most relevant attributes that influence the price; color harmony and color emotions hold almost no explanatory power during this period. Finally, we propose a new metric based on the Herfindahl Index to describe color diversity; this metric seems to be promising at characterizing the effect of the color palette on the price of a painting.     

Proposal of an opponent‐colors system based on color‐appearance and color‐vision studies

A new theoretical color order system is proposed on the basis of various studies on color appearance and color vision. It has three orthogonal opponent‐colors axes and an improved chromatic strength of each hue. The system has color attributes whiteness w, blackness bk, grayness gr, chroma C, and hue H. A method is given for determining Munsell notations of any colors on any equi‐hue planes in the system. A method is also given for determining grayness regions and grayness values on hue‐chroma planes in the system. It is concluded that colors with the same color attributes [w, gr, bk, C] but with different hues in the theoretical space have approximately the same perceived lightness, the same degree of vividness (“azayakasa” in Japanese), and also the same color tone. The tone concept, for example used in the Practical Color Coordinate System (PCCS), is clarified perceptually. The proposed system is a basic and latent color‐order system to PCCS. In addition, the concept of veiling grayness by a pure color with any hue is introduced. Further, relationships are clarified between generalized chroma c(gen) and grayness. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 135–150, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10234     

An attempt to reconstruct the meaning of al‐Tusi's color words

In a text dating between 1259 and 1277, the Persian scholar al‐Tusi presented a systematic arrangement of 26 color terms. We propose a reconstruction of all color terms from al‐Tusi's scheme, in terms of preferred translation, mean CIEL*a^*b^* coordinates and digital representation. This reconstruction is based on a visual experiment with 30 subjects, who identified the Munsell chip best representing each color term. Persian words for which the meaning changed since the time of al‐Tusi were substituted by direct translations. The results show considerable interobserver variability in the colors selected when identifying color terms. This relatively large variation was shown to be a characteristic for memory matching experiments in general. Several specific color terms for which the resulting color variation was particularly large are discussed in more detail, and possible explanations for these variations are proposed. The proposed reconstruction suggests that al‐Tusi's list is largely consistent in modern colorimetric terms, although some large hue shifts are observed for color terms corresponding to green. We found no evidence for blue‐green (“grue”) confusion. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 206–216, 2016     

磷酸二铵颜色发黄原因分析及解决措施

270kt／a磷铵装置用同一种磷酸生产磷酸二铵时,产品颜色由果绿变为黄色。分析其产品颜色变化原因,采取对造粒机管式反应器、二次氨化、返料破碎机的改造措施,减少造粒机氨逸出量,降低中间槽、预洗涤器洗涤液中和度,控制中间槽洗液pH值在2．7以下。改造后洗液和产品颜色稳定在果绿色。     

Theoretical considerations on small color differences ascribed to the standard observer made on the basis of individual color‐matching functions

An analytical method to determine how color‐matching functions influence the perception of chromaticity differences is proposed. We show that, as a consequence of the observer metamerism, a metameric color‐match perceived by one observer may appear to be a significant mismatch to a different observer. It is also shown that, on average, the differences between the color‐matchings made by two different observers can be estimated to be in the order of 2 CIELAB units. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 194–200, 2009     

The effects of functional polysiloxane resins on the color gamut and color yield of dyed polyester

It is important to evaluate the influence of textile finishing using the polymer resins on the color of dyed fabrics. In this article, three functional polysiloxanes modified with different organic groups were used to treat dyed polyester microfiber fabrics. Effects of the polysiloxanes on the color of the dyed polyester were investigated by color yield (K/S), colorimetric data of CIELAB, and the color differences (ΔE). Chemical structures of three functional polysiloxanes were the polysiloxanes with amino groups (polymer A), with perfluorocarbon groups (polymer B), or with quaternary ammonium salts and perfluorocarbon groups (polymer C). Compared with the dyed fabrics treated with the polysiloxane with amino group, the K/S of dyed fabrics treated with the polysiloxane with perfluorocarbon obviously improved. Effects of the polysiloxanes with perfluorocarbon and cationic groups on the color shade of the dyed polyester were noticeable. The fastness had not significantly changed. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2012     

烷基噻唑偶氮类试剂的合成及其显色反应特性的研究

合了成３个新的烷基噻唑偶氮试剂，经元素分析和红外吸收光谱确定了它们的结构。探讨了试剂与８种金属离子的显色反应特性。     

Predicting changes in the color of powders: Does Melamed's model fit to real industrial powders?

In 1963, Melamed proposed a model that expressed reflectance of a powder described as a population of spherical particles of unique diameter as a function of size, shape, and optical characteristics of the powder. This article shows how this model has been adapted to fit to industrial powders. An example of use for industrial quartz is given. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 413–419, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20058