Color and visual complexity in abstract images: Part II

There are a limited number of studies examining color, visual complexity, and visual interest together, and one of the recent studies that tried to bring a new understanding to the association between color, visual complexity, and visual interest was the first part of the current study. Most of the well‐known color studies researching the effects of color on psychology, physiology, emotion, mood, attention, well‐being, visual complexity, and visual interest used isolated color patches that might be lacking in reflecting the dominating factors. Thus, the aim of this study was to find the relationship between visual complexity, visual interest, and color difference (ΔE) values of colors in abstract images, and it was hypothesized that, as the average ΔE value of colors in an abstract image increases, visual interest and visual complexity will increase until reaching a threshold where visual interest and visual complexity start to decrease. In order to test the hypothesis, a new abstract image was generated and colored. The generated abstract image was rated by 120 undergraduate students from the Faculty of Art, Design and Architecture. As the results of the study indicated, there was an inverted U‐curve relationship between average ΔE values and both visual interest and visual complexity in abstract images.     

彩色红外反射型隔热涂料的研发

介绍了研发彩色红外反射型隔热涂料的3条途经,即采用彩色红外反射颜料、彩色透射型红外节能颜料和稀土纳米材料。     

Optimization of color reproduction on CRT‐color monitors

In the present experimental study, we quantify the influence of the brightness and contrast levels of a CRT‐color monitor in the color reproduction of 60 Munsell chips distributed throughout the chromatic diagram. The images were captured by two CCD cameras, and the color differences were evaluated after reproducing the chips on a color monitor (the experiment was performed with 3 different monitors) for 9 combinations of brightness‐contrast levels. We evaluated the color differences with 3 different formulas: CIELAB, CIELUV, and CIE94. The results indicate that the optimal settings of a monitor, to minimize the color differences, is a medium or minimum brightness level in combination with a maximum contrast level. This combination ensures a more faithful color reproduction with respect to the original image. © 1999 John Wiley & Sons, Inc. Col Res Appl, 24, 207–213, 1999     

Color preference affected by mode of color appearance

Most color preference research focuses on colors in an object color mode. In our daily life, however, colors are perceived not only as an object color mode but also as other modes, such as unnatural object color and light source color modes. To explore the effect of the color appearance mode on color preference, we examined the relationship between color preference and the mode of color appearance. Thirty‐three color chips were chosen from the Munsell notation varying in hues and chromas. The color chips were presented in different color appearance modes by changing the subject's room illuminance and the color chip room illuminance. The experimental results showed that the brightest and most saturated colors were preferred. It was found that the subject preferred color in a light source color mode and unnatural object color mode to color in an object color mode. Moreover, we found that hue had a small effect on color preference in the light source color mode. We also investigated the relationship between color preference and the perceived color attributes (perceived chromaticness, whiteness, and blackness). In a supplementary experiment, elementary color naming was conducted. The results showed that the perceived chromaticness, perceived whiteness, and perceived blackness play a role for the determination of color preference for different color appearance modes. We, consequently, suggest that color preference is dominated not only by color attributes but also by the mode of color appearance. © 2009 Wiley Periodicals, Inc. Col Res Appl, 2010     

Color corrected single scale retinex based haze removal and color correction for underwater images

Underwater images are affected by scattering of dust particles leading to hazy images. The difference in absorption of light at different wavelength leads to colorcast. Restoring underwater images from haze and colorcast degradation is a challenging task. This article proposes color corrected single scale retinex algorithm for the restoration of hazy and colorcast underwater images. Further, the illumination of the underwater image is enhanced through illumination enhancer. In order to correct colorcast, the underwater images intensity shifters are proposed. Blur, natural image quality evaluator, blind/referenceless image spatial quality evaluator, entropy, peak signal to noise ratio are the metrics used to evaluate the performance of the proposed restoration technique and compared the output with the existing techniques. Compared to the existing techniques the proposed algorithm prominently removes haze and colorcast present in underwater images. The study excludes retinex-with-reset models from consideration.     

Improving color reproduction accuracy of an OLED‐based mobile display

For improving color reproduction accuracy of mobile displays, we recently developed a generic model for device‐specific display characterization model that also accounts for the influence of illuminance from ambient light. In the present article, this MDCIM model (Mobile Display Characterization and Illumination Model) is applied to a Samsung Galaxy S4 display, representing OLED displays. The performance of the model was tested by determining the values of all model parameters using publicly available technical data only. We organized visual tests under various ambient illuminance levels from 600 to 3000 lux. Seven observers compared the color of displayed images with the color of physical samples. With the MDCIM method, the quality of the color match was shown to improve considerably as compared to using only device‐independent encoding color space. On a five‐point scale to quantify color reproduction accuracy, the MDCIM resulted in more than 1 unit improvement at 1000 lux illuminance. At lower and higher illuminance, the improvement was even larger. Color reproduction accuracy was found to be at least reasonable, according to the subjective assessment of visual observers, for more than 75% of the samples when using the MDCIM method, but only 20% or less when using the common device‐independent encoding color space.     

Experimental determination of the laws of color harmony. Part 4: Color preference and the color harmony content

In 1956, we decided at the Budapest University of Technology and Economics to start a large‐scale experiment on color harmony. The experiments and the processing of the experimental results have been completed in 2006. These experiments, described in this article, form a study of how much are people, participating in the experiment, influenced by their own personal color preference in judging the harmony content of a composition. These experiments have utilized the results of former (1958–1969) color preference experiments and the system of color preference indexes, which were developed by the generalization of those results. Within the framework of these experiments, conducted between 1998 and 2006 there were 24 compositions, shown to the participants, at first one by one, then in pairs and at last in groups of six. They had to assess the harmony content of the compositions and award a score on a scale between 0 and 10. Each composition possessed a specific amount of harmony content according to the rules of color space, based on the Coloroid harmony threshold and verified by former experiments. In these experiments the number of elementary observations were 135 568. The people participating in the experiment were approximately equal number of men and women, from the age group between 10 and 70 years. During processing, by using the color preference numerical indexing system, we compared the results of those experiments with the color preference of a similar age group, by using color compositions, identical to the ones used in the present experiment. We have found that the sensation of the color harmony and its intensity have a strong relation to how the observers relate to colors and also their color preferences. The sensation of color harmony is also influenced by the gender and the age of the observer. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 210–224, 2009     

Microstructures and luminescent regulation of Ce-doped silicate glasses with high transmittance and thermal stability

The traditional model for wLEDs usually encapsulates the phosphor and resin mixture on the InGaN blue-emitting chip. However, the poor thermal stability of silicone resin will lead to the reduction of the luminescent intensity of the wLED devices. Glass has excellent thermal stability and transparency, which is a promising alternative to resins. In this work, Ce-doped silicate luminescent glasses have been developed by a high-temperature melting quenching method in air atmosphere. The luminescent intensity can be enhanced by increasing the heat treatment temperature and extending the heat treatment time in 10%H₂/Ar atmosphere because Ce⁴⁺ ions can be reduced to Ce³⁺ ions. However, when the heat treatment temperature reaches 850°C, the generation of precipitates in the glass can reduce the luminescent intensity. The transmittance of glass can reach 87%, and the highest luminous intensity obtained when heat treated at 800°C. The glass transition temperature is 740°C and the thermal conductivity of the glass is .95 W m⁻¹K⁻¹, which is about five times higher than that of resin. The results show that the emerging Ce-doped silicate luminescent glass could be the potential material for wLED applications.     

Heuristic analysis influence of saliency in the color diversity of natural images

The estimation of chromatic diversity of natural images is commonly quantified through the computation of the number of discernible colors and has received much attention because of the different implications it has. However, the relationship between that number and the number of colors that really attracts the attention from an observer is still not clear and has been given little attention. New concepts about salient discernible colors‐the salient chromatic diversity of images‐ and remarkable salient colors‐connected colors in the same salient image area‐are introduced as opposed to the classical number of discernible object colors, which is usually evaluated for the global image without differentiating between probable attended and non‐attended image regions. We have used different well‐known saliency models to locate the salient regions in the scenes and have heuristically studied the extent to which those models preserve the chromatic diversity of natural images. Based on a bottom‐up approach, a reduction of around 40%‐55% in the number of discernible colors were obtained, and not all saliency algorithms preserved a uniform sampling of the original color gamut. Thus, our results suggests that particularly the graph‐based visual saliency model got good low dissimilarity values in comparison with other approaches that put emphasis solely on color as the main low‐level feature. Furthermore, we have introduced a quantification scheme of the average number of remarkable salient colors appearing in the images, and have proved how the heuristic‐based analysis of salient image areas can be used to create segmented images automatically according to their salient chromatic diversity.     

Color appearance modeling of bicolor striped woven fabrics considering neighboring color effects

In this article, the effect of the spatial and colorimetric attributes of neighboring color on color appearance shift in bicolor striped woven fabrics is investigated. A total of 240 test/neighboring woven color combinations were constructed in four different striped paradigms. Each test color in the combinations was visually assessed by 12 observer panels with the use of the magnitude estimation method estimating the magnitude of perceptual color attributes lightness, colorfulness, and hue. The visual estimates obtained were analyzed statistically by employing correlation and simple regression methods, and, as a result, the following significant neighboring color effects were detected and individually defined: (1) neighboring color's size, lightness, colorfulness, and hue on test color's lightness, (2) neighboring color's colorfulness and hue on test color's colorfulness, and (3) neighboring color's hue on test color's hue. Furthermore, through multiple regression analysis, color appearance models by which the lightness, colorfulness, and hue of bicolor woven fabrics can be predicted were derived. The predictive performance of the models was evaluated by calculating the difference between the visually estimated and the predicted color appearances, using ΔL*, ΔC*, Δh°, and ΔE_CMC(2:1). Among all the derived models, the model producing the smallest mean error was chosen as a final model, and its great accuracy in color appearance predictions was verified through further statistical evaluation. It is envisaged that the findings of this research are of benefit to design textile products with bicolor striped woven fabrics to have desired color appearances. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 512–521, 2017     

Color selection in the consideration of color harmony for interior design

A color selection method that considers subjective principles is becoming more and more necessary in a computer‐based color management system. However, one from an engineering perspective has received limited attention. Previously, we developed an approach to measure the degree of color harmony by the similarity of a pleasure‐related function, CLD (color linguistic distribution), to a RHD (reference harmony distribution) on a one‐dimensional image scale of EXCITING–CALM. Following this approach, a new color selection system is presented in this article by modulating the CLD on the image scale. The procedure used is to encode an inharmonious image as a CLD, then it is modulated and referred to as a RHD, called an imagery specification. Finally, the specified CLD is decoded and reconstructed as a harmonious image in an operated color space. Four types of RHD are compared: three ideal fuzzy sets scaled to extremely calm, quite calm, and slightly calm, and the practical one measured from social trends. For verification, the harmony grade of the decoded image can be measured based on the referred RHD. As a result, four times the harmonic degree of the decoded image is gained than the originally encoded one. For application purposes, the proposed system is suitable for applications related to human subjectivity. © 2000 John Wiley & Sons, Inc. Col Res Appl, 25, 20–31, 2000     

Color loci placemaking: The urban color between needs of continuity and renewal

The article presents the theoretical framework and the operational concepts of a research, finalized to explore and verify the prerequisites of an approach to urban color that, while recognizing to color the flexible as well as transient capacity to respond to the successive and multiple demands that characterize the urban space, sees a possible way of coexisting between the needs of continuity and renewal. Searching to understand the modalities and possibilities through which colour can intervene in the processes of transformation of the city to support both the needs of resignification and reappropriation and those of conservation and enhancement of the vital identity of each single place, the research looked on one side to the experiences gained within the colour plans and Lenclos' geography of colour and on the other side to the different and diversified experiences developed within the idea and practice of placemaking, aimed at the recognition and enhancement of the collective and plural creative dimension that colour seems effectively able to interpret. The term “color loci placemaking” was introduced to summarize this mode/possibility of understanding and approaching urban color, characterized especially by the attention for the specificity of each single place and the human factor underpinning place‐experience.     

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.     

Color specification of a single strand of yarn from a multispectral image

Many applications in textile require color measurement of single strands of yarns due to unavailability of a mass of consecutive yarns. While multispectral imaging systems can capture images of single strands of yarns, an unavoidable problem accompanied is how to specify their colors from images, in which pixel values vary with positions owing to three‐dimensional shape of yarn. Based on the response of multispectral imaging systems to single strands of yarns, this article formulates the color specification problem as an optimization question and four methods are proposed: average of all pixels (AA), average of pixels in central area (AC), maxima of all pixels (MA), and lightness weighting method (LW). The first experiment analyzed color distribution of pixels on a single strand of yarn. Experimental results show pixels in central area have smallest color variation and largest intensity. The second experiment compared the proposed methods. Results show that CIEXYZ, L*, and C* values specified by the AA and MA methods are lowest and highest. Finally, colors of single strands of yarns specified by the proposed methods were compared with spectrophotometric colors of yarn windings using 12 pairs of single strands of yarns and yarn windings. Experimental results show the MA method yields the smallest lightness and chroma difference compared with spectrophotometric colors of yarn windings. The average color difference between spectrophotometric colors of yarn windings and multispectral imaging colors of single strands of yarns specified by the AA, AC, MA, and LW methods is 3.45, 2.72, 2.37, and 3.33 CMC(2:1) units. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 500–512, 2016     

Color characteristics of costumes for Korean folk festivals and color consciousness of Koreans

The purpose of this study was to identify the color characteristics of Korean culture, the color consciousness of Korean people based on their arche‐pattern sentiment, and to analyze the colors of the costumes of Korean folk festivals, which clearly suggest the archetype of Korean tradition. The range of this study is focused on Korea's important intangible cultural assets in which the colors used in folk festivals were fully expressed, and 20 folk games and plays were selected from among different festival events. Hundred and fifteen pictures from these 20 folk games/plays were used to extract the costume colors and conduct color analyses. Among 647 colors extracted in total, this article used 199 colors after excluding overlapping colors. The results show that Korean folk festivals have served as the medium of nondifferentiation that goes beyond the differentiated order of reality. Costumes for these Korean folk festivals, such as folk games and folk plays, have a sacred meaning as ritualistic robes. Five element colors in these costumes for the Korean folk festival are used as a means of circulatory thinking and as a symbol of Chaos—the very origin of undifferentiated thinking—beyond one's daily lives. It was found that these highly chromatic five element colors have always been used, wherever this undifferentiated thinking was strongly expressed. Delivering visually strong impacts, these five element colors symbolize the concept of the Arche‐pattern theory, being related to infinite freedom without any restrictions. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2010     

Chroma variations and perceived quality of color images of natural scenes

Transformations of natural images in the perceptually uniform CIELUV color space have been investigated with respect to perceptual image quality. To this end, digitized color images of four natural scenes were described on the basis of their color point distributions in the CIELUV color space. A new set of images was created by varying the chroma value of each pixel while the lightness and hue angle were kept constant. The chroma was changed in two different ways: (1) through the addition or subtraction of the same amount of chroma to or from the chroma value of each pixel; (2) through multiplication of the chroma value of each pixel by a constant. In three experiments, subjects judged the perceptual quality, colorfulness, and naturalness of the images on a ten-point numerical category scale. The results indicate that colorfulness is the main perceptual attribute underlying image quality when chroma varies. Colorfulness itself was found to depend on both the average chroma and its variability. In general, the subjects preferred slightly more colorful images to the original ones. The perceptual quality of the images was found to be closely related to the naturalness of the images. © 1997 John Wiley & Sons, Inc. Col Res Appl, 22, 96–110, 1997     

Design and performance of a color chart based in digitally processed images for sensory evaluation of piquillo peppers (Capsicum annuum)

A chart of color standards for visual color evaluation of the piquillo pepper (Capsicum annuum) has been designed. The chart comprises six rectangular regions of digitally processed images of piquillo peppers covering the observed visual range of variability in this product. Colorimetric characterization of piquillo peppers and the color chart has been made using instrumental color measurements. Both trained and untrained sensory panels tested the reliability of the designed color chart. The Pearson correlation coefficient between color chart scores and subjective color quality scores is 0.831 (P < 0.01). Correlation between all instrumental color coordinates, with the exception of CIELAB a*, and visual color chart scores are significant at P< 0.001 and Pearson correlation coefficients range from ?0.747 with CIELAB chroma C* to ?0.926 with CIELAB hue angle h. Repeatability of visual color chart scores is completely satisfactory, having found no statistically significant differences between color chart scores in samples evaluated twice by panelists. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 305–311, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20026     

Color association research on red‐green dichromats in the color ergonomics of user interface interaction

With the development of our modern information society, digital products have become integrated into daily life. Research on the color ergonomics of user interfaces is a pressing issue. However, color‐vision‐deficient individuals (CVDIs), who account for 4.25% of the population, must use interfaces designed for individuals with normal color vision; the demands of CVDIs have not been sufficiently addressed. In this article, we investigate color associations in the color ergonomics of user interface interaction in a manner that aims both to improve interaction efficiency and to meet the psychological needs of CVDIs. First, we study color physiological cognitions in the color interactions of user interfaces for red‐green dichromats (RGDs) to determine the single‐color, two‐color, and three‐color combinations with high discrimination for a later experiment. Second, we explore the psychological–cognition relationships of colors in user‐interface interactions for RGDs. In an experiment involving 10 pairs of association semantemes and corresponding colors, the experimental results show that RGDs have different color cognitions caused by specific visual color expressions and unconscious environmental influences. Therefore, this article argues that RGD design should consider not only the habitual colors of solidified cognitions but also instinctive color associations. Finally, based on the results of previous experiments, we apply association color to the new interface design of computer security software (360 Total Security) for RGDs. Experimental results indicate that the application of color association in our new design can improve both interaction efficiency and CVDI user experience. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 547–563, 2016     

Multiple roles of color information in the perception of icon‐type images

Despite the ubiquity of icons in computing and mobile devices, the role of color in icon‐based interface design has yet to be fully elucidated. This study began by conducting a card sorting experiment to determine the importance of color in the perception of commercial icons, as opposed to the simpler icons typically used in a laboratory setting. The study also sought to ascertain the importance of color when considered alongside other visual attributes in the general perception of icons. Participants were then asked to answer preset questions as a means of determining the relationship between the known color properties (e.g., hue, saturation, and brightness) of icons and their functional meaning, effectiveness in conveying meaning, and visual attractiveness. Finally, the speed and accuracy was assessed by which participants recognized well‐known icons rendered using familiar and unfamiliar colors. The empirical results identified color as an important attribute in the process of sorting icons, far exceeding other visual attributes including shape, complexity, pictorial style, and orientation. Nonetheless, it appears that color is not necessarily dominant in the initial stages of sorting. The results also revealed that color is closely related to visual attractiveness but largely irrelevant to effectiveness in the conveyance of meaning. The study also confirmed that correct color information is crucial to naming accuracy and the speed at which icons are recognized. Finally, the results indicate that icons lacking a unique symbol as a cue to recognition rely heavily on their signature color for identification. This study opens up several avenues of research by which to enhance our understanding of the functional role of color in icon perception.     

Fixed range scales applied to the evaluation of color: Comparative analysis between the Munsell System and the Natural Color System

In this article, we discuss the effect of anchoring on the estimation of chromatic variables, which occurs when fixed range scales are used in psychophysical measuring. In order to do this, we compare the Munsell System and the Natural Color System (NCS), and an alternative system that employs a scale of grays as a yardstick against which to measure value and saturation. During experimentation, observers evaluated 60 matte surface color samples, following the methodology proposed by each system, but without using their respective color atlases. The data obtained reveal results that are compatible with the measurements based on the Munsell System and the NCS. By applying the gray‐scale method, the value measurements improved, whereas the saturation measurements were overestimated in samples with low reflectance. In all the cases, hue shifts were observed and thought to be attributable to the variation in luminance revealed by the samples. Judging by the similarity of the results obtained, it can be assumed that when fixed range scales are used, measurements will be anchored to their extremes, equaling every measurement made with them. © 2003 Wiley Periodicals, Inc. Col Res Appl, 28, 103–112, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10130