Hierarchical emotional color theme extraction

Artists usually carefully select different colors in artistic work so as to convey special visual and emotional feelings. Color theme extraction techniques can help users to acquire the color styles in an image. However, current color theme extraction methods ignore the emotional factors, and they can only provide a single theme result for an image as well, neither of which meet people's favor on different colors under different mood states. This article introduces the conception of emotional color theme, introduces the color emotion theory into color theme extraction, and proposes a novel emotion color theme extraction framework. To achieve these goals, we perform the theme extraction with emotion value of each pixel instead of color value. The emotional discrepancy is proposed between the colors in the theme to evaluate a color theme quality and prove it with color theme dataset. Then a data driven approach is adopted to optimize the color theme. Different from previous optimizing strategies, we built the emotional relation between the target theme and the candidate theme. Our method can enhance the color editing results of previous methods, e.g., for color transfer our results can demonstrate hierarchical emotions from a single reference image. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 513–522, 2016     

Quantitative evaluation of color harmony via linguistic-based image scale for interior design

In order to develop a computer-based color consultation system, a quantitative evaluation of color harmony for interior images is constructed by using a linguistic-based image scale. Conventionally, color harmony from any engineering perspective has received limited attention, because its successful evaluation requires the development of pleasure-related features. In this study, a new pleasure-related function of color linguistic distribution (CLD) is proposed to quantitatively represent the mental color impression of interior images upon a designed one-dimensional linguistic-based image scale of EXCITING-CALM. Supported by a database that includes fashion trends, the distribution state of CLD is capable of indicating the fashion trends in Taiwan. Also, on the image scale, the grade of color harmony can be measured by its CLD similarity to a reference harmony distribution (RHD). Evaluated results demonstrate that interior design is primarily dominated by (low) saturation and (high) brightness. Also, results based on CIE1976 L*a*b* and CIE1976 L*u*v* color spaces are observed to be better than those based on the hue-dominated method of Moon-Spencer theory in corresponding with human's linguistic similarity, questionnaire-based harmony evaluation, and social trends. Moreover, our solution percentage has been investigated as 72.3%, which is better than those of the Moon-Spencer theory and of the “Law of Inverse Ratios of Areas.” For application purposes, the proposed system is suitable to analyze the mental impression of products from the perspective of the customer. © 1996 John Wiley & Sons, Inc.     

A novel method for fabric color transfer

Fabric color design is a complex process in textiles and clothing industry. A new method for fabric color selection and transferring is proposed in this study. An automatic way to select the colors from the natural images is developed for fabric color design. Based on these colors, a fabric image is then used for color transferring. The fabric image is processed by a bias field estimation operation, and the membership function of the color deviations of the image has been obtained. According to the selected colors and the color membership function, the fabric image colors can be changed and transferred to a new image that preserves the similar texture appearance but with significantly different color effects. The experimental results confirm the effectiveness of the proposed method. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 304–310, 2015     

An interactive method for generating harmonious color schemes

We present an interactive visualization tool for generating color schemes that can be used by both professional artists and novice designers to improve their design efficiency. The method is developed on two color harmony principles of familial factors and rhythmic spans from conventional color theories. The interactive tool makes use of these principles for users to interactively generate colors palettes containing harmonious combinations in the hue, saturation, and lightness color space in as few steps as possible. A pilot study with 20 participants has shown that this tool provides efficient workflow, color‐scheme harmony, and intuitive interaction, demonstrating the usefulness of the method. This work contributes to an artistic‐theory driven harmonious color‐scheme generation and to interactive user interfaces visualizing color relationships. © 2012 Wiley Periodicals, Inc. Col Res Appl, 39, 70–78, 2014     

Quantifying the color palettes of Naghsh-e Jahan Square in Isfahan

In the 1960s, Jean-Philippe Lenclos introduced a structured methodology for determining the color palettes of urban environments. After half a century, this method is widely used all over the world. Since this process contains subjective and time-consuming steps, we propose a quantitative improvement of Lenclos' methodology by introducing a fully digital procedure. This removes observer subjectivity and dependence on local illumination conditions. We applied the digital process to the four monumental buildings of Naghsh-e Jahan Square in Isfahan, a masterpiece of world architecture. The resulting color palettes are more accurate than those obtained in earlier studies. We obtained more accurate color coordinates, characterized by a wider color gamut, and quantified color variations within buildings and between monuments as well.     

Formulation of interior design color palette based on the regression analysis of digital color samples

Various color models have been developed to represent color as a synthetic construct of its component attributes. The CMYK color model is based on a mathematical framework efficient for digitally planning and processing the colors for a domain‐specific application such as interior design. The CMYK color model correlated with the Munsell system would also increase usability and effectiveness. In this research, we suggest a computationally assisted systematic method to formulate a color palette useful for interior design. A continuous process of sampling, statistical analysis, and computational manipulations has been performed to derive a desirable color palette. First, color samples have been extracted from the representative interior design cases of residential buildings, offices, and commercial spaces. Second, the interrelationships among C, M, Y, and K values in all samples have been statistically analyzed followed by calculating the number of elements in the numerically categorized sets for C, M, or K value. New CMYK combinations were generated by using selected sets of C, M, or K value showing relatively dominant presence in the original samples. Then, the statistically extracted correlation function was used to propose a complete list of CMYK color combinations for interior design. The resulting CMYK combinations were then converted into the values represented in the Munsell color system. We envision that the proposed approach can increase both applicability and efficiency of the resulting color palette by considering both intuitive and mathematical color models with the support of a computational data processing technique. © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 135–145, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20092     

A consultation and simulation system for product color planning based on interactive genetic algorithms

In the early stage of a design process, it is important to create numerous and varied possible color plans for the target consumer group. These color plans help individual designers quickly find a few good color design schemes and give the design team ideas for brainstorming. The color plan of a product consists of the color combinations of its components and decorative patterns, which strongly influence the feelings of customers and thus their desire to purchase. However, very few studies have discussed these issues. In this study, a consultation and simulation system for product color planning that helps designers obtain the optimal color planning for components and decorative patterns of a product is proposed. This system includes two parts: one uses the interactive genetic algorithm to establish a creative evolutionary system that can interact with a designer to explore novel design schemes; the other extends the boundary extract algorithm to establish a color simulation system that can apply colors to the areas of product components and decorative patterns for color simulation. Finally, a case study of color planning for a motorcycle model is used to verify the feasibility of the proposed system. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 375–390, 2013     

Detection and modification of confusing color combinations for red‐green dichromats to achieve a color universal design

Color‐vision deficiency is a relatively common genetic condition, which often leads to the obstruction of necessary information in colored images. It is important to minimize such inconvenient effects in communication using colored images from a universal design perspective. The universal design principle stipulates that all environments and products should be usable by all people, regardless of age, physical attributes, and ability. This article proposes a method to detect color combinations in a given image that would confuse color dichromats, and suggests a way in which to modify them to make the image easily distinguishable for both normal and dichromatic observers. Confusing color combinations were detected based on a color‐difference calculation using simulations of how the color would appear to dichromats. The confusing colors were then modified based on the minimization of an evaluation function, which was defined as the sum of the degree of confusion and the degree of color change from the original image. Several colored images obtained by the proposed method were compared with the originals by red–green dichromatic observers who judged them to be clearer, thereby confirming that the proposed method was effective for color rendering for universal design. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 203–211, 2008     

Preference for accent and background colors in interior architecture in terms of similarity/contrast of natural color system attributes

Color combination criteria are said to entail an affective response in interior design. We investigated the color combination criteria that orient the preference of current observers, after Le Corbusier's 1931 Salubra keyboards. We explored the similarity/contrast in Natural Color System (NCS) hue, blackness, and chromaticness in 312 combinations with four colors, two backgrounds and two accent colors, coming from 43 individual colors, on the walls of a simulated interior of a bedroom from the Swiss Pavilion (Le Corbusier, 1930-1931). Participants were 644 students of architecture and interior design in Western Europe and Near East, who evaluated with a Likert scale their preference for virtual images via an online survey. Results indicate that the most preferred color combinations are those with hues closer in the color wheel, being the similarity between hues in the backgrounds more important than in the accent colors, and with NCS B30G to G as the most preferred hues. Observers preferred color compositions with blackness under 10% and similar blackness between the two background colors, together with a certain blackness contrast between these background colors and the two color accents. Similarly, observers liked color compositions with low chromaticness and low chromaticness difference among the four colors of the composition.     

Color,arousal, and performance—A comparison of three experiments

Three studies of the psychological and physiological effects on people of colored room interiors are described. Experiment 1 compared a colorful and a gray room, whereas in experiments 2 and 3 red and blue rooms were compared. The results indicate that the color of an interior space will have effects on many different levels. The perception of the room itself was affected, and the colors also had an impact on the emotions and physiology of those who stayed in the rooms. Strong, especially red, colors and patterns put the brain into a more excited state, sometimes to such an extent as to cause a paradoxical slowing of the heart rate. Introvert persons, as well as those already in a negative mood, became more affected than others, which caused severe changes in their performance. The series of experiments described here were among the first to be carried out in full‐scale rooms painted or otherwise decorated in various colors. One practical implication is that a moderate use of good color design will serve to improve the overall mood and well‐being of people. In future research more emphasis should be placed on color, as just one component in the highly complex real‐life situations. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 141–152, 2009     

Dancheong colors used for Korean cultural heritage architecture restoration

Dancheong is Korean traditional decorative coloring on special wooden buildings, and it has been preserved by Danjeongjang as a national intangible cultural heritage—a craftman with a special skill to paint dancheong. All dancheong in the national heritage have been managed by the Cultural Heritage Administration following the standard procedure. However, there is no available information about final colors. In this study, a total of six different dancheong color paletts were prepared by six different apprentices of the living national treasures. In total, there were 20 different colors and 12 colors were shown in all six palettes. The color measurement result showed that well trained dancheong painter can reproduce the same colors repeatedly with fairly high precision with 1.8 on average except two colors—Ju‐hong and Yang‐cheong—showing high chroma differences, but with very similar lightness and hue angle indicating that hue of dancheong colors is the most important factor to judge the correctness of the color preproduction. The dancheong colors show large variations depending on the painters but the painters trained by the same teacher have the similar color palettes. Further in‐depth dancheong color investigation is needed to fully understand the contemporary dancheong colors.     

An intelligent color design method for visual communication design for public crisis

During a crisis, people's emotions are dynamically affected by changes in the environment, and by the attributes of object and subject in ways that depend on an emotion's essential characteristics. Negative emotions can cause psychological harm to people, but specific visual colors can instantaneously dispel or reduce those negative emotions. We developed a color design method based on a hybrid intelligent algorithm to predict accurately the significant negative emotions of people during a public crisis, and to explore the relationship between color structure and negative emotions developed. A Fuzzy Bayesian Network prediction model was constructed of people's significant negative emotions during a public crisis. Then, the concept of color cube was proposed that related color combinations to  particular emotions. Finally, based on the emotion arousal experiment and the BP neural network, the nonlinear mapping relationship between negative emotion and color cube was analyzed to predict the fading versus stimulating color structure of the significant negative emotions. This mapping provides a reference for the color design of visual communications during a public crisis. Our results show that the prediction model of emotions and color design method were effective.     

Research on color harmony of building façades

In this study, the 28 primary colors and 11 complementary colors suggested by Chang et al in their investigation on building colors in Wanhua District of Taipei City were taken as color samples. The two-color combination mode was adopted to obtain 308 simulation photos, and two-color harmony was discussed from the perspective of visual evaluation using psychophysical tests. This study explored building façade color harmony in the CIELAB color space, and the relationship between the color attributes (hue, lightness, and chroma) and the color harmony, and between the differences of the color attributes and color harmony. It found that a high lightness of a building's primary color is associated with a high level of building color harmony, while the color harmony is reduced when the color falls in the green or blue sector in the CIELAB color space; a greater lightness difference between building façade colors is associated with a higher level of building color harmony, while the colors are disharmonized when they tend to the blue sector in the CIELAB color space. The contribution of this study is to summarize the principles for the application of building color harmony in urban renewal, and proposed suggestions on building color harmony in the urban renewal process.     

A systematic approach of predicting color preference on the basis of gray relational grade

During the color design process, it is critical to create diversified color schemes for various consumer groups. It is also important to allow members in a design team to brainstorm for creative ideas. A theory of inspecting natural color elements was proposed in this study based on the CIE 1976 (L*,a*,b*) (CIE 1976) color space and the fuzzy c‐means clustering method. A calculation model was built to determine people's preference for colors based on a serialized system. To determine which factors affect the prediction of consumers' preference for a series of products, a gray relational color preference system was used in combination with gray relational grade so that a designer can obtain reasonable prediction results. The proposed system recommends not only the optimal colors for a product but also the optimal color scheme for a series of products.     

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.     

Product color emotional design adaptive to product shape feature variation

When a user selects a product, he/she considers the emotional experience induced by the product color. However, when affected by product shape feature, the color image perception space of a user becomes more complex and dynamic. To address this problem, a product color emotional design method adaptive to product shape feature variation is proposed in this article. Based on psychological means, factor analysis and semantic differential methods are used to elucidate the mechanism for the formation of a color image perception space of a user influenced by product shape feature. Using support vector regression, a product color image evaluation model adaptive to product shape feature variation is constructed, and is then optimized via a genetic algorithm. A corresponding design system is constructed based on the method proposed in this article. A case study involving the design of a thermos for children is presented to demonstrate the operational procedure involved in the proposed method and to verify its performance. The results of the verification experiments confirm that the design scheme from system recommendation essentially meets the anticipated image target and assists the designer effectively. The method and system proposed in this study can generate a product color design scheme, which is unconstrained by shape feature and can satisfy user emotional preferences and needs, and have a certain applicability and practicability.     

A novel Color Rendition Chart for digital tongue image calibration

Digital tongue images are usually acquired by a camera under specific illumination environments. In order to guarantee better color representation of the tongue body, we propose a novel tongue Color Rendition Chart acting as a color reference to be used in color calibration algorithms to standardize the captured tongue images. First, based on a large tongue image database captured with our digital tongue image acquisition system, we establish a statistical tongue color gamut. Then, from the first step, different quantities of colors in the Color Rendition Chart are determined via experimentation. Afterwards, results using X‐Rite's ColorChecker® Color Rendition Chart (a standard in the color calibration field) are compared with the proposed tongue Color Rendition Chart by applying the color difference calculation formula of CIELAB and CIEDE2000 as a reference for the mean color calibration error. The results show that the proposed tongue Color Rendition Chart, which has 24 colors, produces a much smaller error (CIELAB —8.0755/CIEDE 2000—6.3482) compared with X‐Rite's ColorChecker® Color Rendition Chart (CIELAB 1976—14.7836/CIEDE 2000—11.7686). This demonstrates the effectiveness of the novel tongue Color Rendition Chart.     

Product color emotional design considering color layout

Emotional experience and demand for product colors are important factors in users' decisions to buy and use a product. Therefore, accurately characterizing users' emotional responses of the product's color has become a significant consideration for product color design. However, a product color design problem exists in which it is challenging to accurately and efficiently position users' color image space because consumers have completely different image perceptions when encountering a large number of color schemes generated by different color spatial distributions. For this reason, this article proposes a product color emotional design method that considers the color layout. A table is built of an elemental composition for product color design, which contains color layout forms. This article also establishes a mapping model based on the semantic difference and back propagation neural network between the users' color image perceptions and the elements of the product's color design. The system recommends a color layout form that matches the users' emotional image goal through the k‐nearest neighbor algorithm, and then the form is initialized using a genetic algorithm. The system can realize the solution to the optimal product color scheme by optimizing and evaluating the population. Designers can make intuitive choices and decisions through the product color recommendation system. Through an example of color design for industrial vacuum cleaners, this article shows that the method has satisfactory feasibility and applicability for solving the problem of the optimization of product color design with color layout forms.