A luminous efficacy model for a white light‐emitting diode (LED) cluster was developed, and five α‐opic efficacy ratios (γ α,Vs) of intrinsically photosensitive retinal ganglion cells were adopted in order to quantify its nonvisual performance relative to natural light. A tunable C/A/R LED cluster, which consists of the cyan LEDs with green phosphor excited by a blue LED, the amber LEDs with green

Color reproduction is a science in constant development. In this article, a new model to solve the color recipe prediction problem using a genetic algorithm is proposed. The objective is to optimize the color recipe prediction stage by determining the dyes to use in a mixture and their respective proportions to reproduce the target color. Two ranges of dyes were used for dyeing 100% cotton woven fabrics:

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

Under the background of urban renewal protection and old city transformation, problems such as clutter, distortion, and disorder appear in the historical style area. These problems have greatly impacted and damaged the cultural heritage and historical research of the style area. To carry out the urban renewal movement more reasonably, this article selects the historical features of the Old Town of

This study aims to research the effect of the interface background color choice on the emotion of university students. The study group consisted of 929 Turkish students studying at the vocational colleges of technical and social sciences in Çanakkale Onsekiz Mart University, Turkey. In this study, the descriptive method was used. A color effect form developed by the researcher was used. The validity

A color space is a three‐dimensional representation of all the possible color percepts. The CIE 1976 L *a *b * is one of the most widely used object color spaces. In CIELAB, lightness L * is limited between 0 and 100, while a * and b * coordinates have no fixed boundaries. The outer boundaries of CIELAB have been previously calculated using theoretical object spectral reflectance functions and the

The aim of this study is to investigate the effect of toothbrushing and paste repolishing on the colour restitution of long‐term coffee discoloured prefabricated and direct resin composites. One prefabricated (Componeer‐Coltène) and three direct resin composites (Brilliant Ever Glow‐Coltène, Essentia‐GC, Harmonize‐Kerr) were tested. Componeer samples were prepared with and without polishing while the

Colour meaning is a challenging decision in interior architecture during the design process; however, specific meanings within different interior types have not yet been investigated. This study explored colour meaning in the context of residential interior types (eg, bedroom) under controlled conditions using 42 Munsell colours varying in hues, value, and chroma levels, with 14 adjectives (eg, comfortable

This article describes the results of an experiment to evaluate people's impressions of a live landscape scene, the famous West Lake in Hangzhou, China. We invited seventy students from different academic backgrounds to participate in this project. The goals of this study were to find a method for the evaluation of the perception of a live scene, to reveal differences for subjects from different backgrounds

A novel methodology is proposed to identify the distribution of the intensity of the illuminant across a real‐world image; with this information, the image can be classified as a homogeneous or nonhomogeneous lighting source. A criterion is proposed for deciding whether the illumination in the tested image is homogeneous or nonhomogeneous. This criterion is based on well‐established methods that are

Artworks based on Xuan paper or silk and painted by organic or inorganic pigments are highly responsive to light due to their materials and manufacturing technologies. They belong to the highest level of light responsive exhibits stipulated by International Commission on Illumination (CIE) and are vulnerable to fading and discoloration caused by radiation from light sources. The choice of light sources

This article models multicolor perceptual features to investigate human perceptual responses to multiple colors based on a subjective evaluation experiment. First, an image set containing 164 multicolor samples was constructed, and multicolor objective features containing two categories with 60 dimensions were designed and quantified. Based on this, the 164 samples were evaluated by 30 subjects based

Light is scattered and absorbed in the atmosphere producing visual effects that increase with viewing distance. Contrast and chromatic diversity decrease with distance, thereby modifying the way objects and scenes are perceived. Although some perceptual compensation to produce color constancy of individual surfaces has been reported, it is unclear to what extent unknown original images can be visually

In this study, it was aimed to develop a freshness indicator label that changes color with spoilage of fish. Hydroxyethyl cellulose‐based indicator labels were prepared using two different mixed indicator (bromothymol blue/phenol red, cresol red/thymol blue) formulations. The functionality of prepared indicator labels was tested on anchovy (Engraulis encrasicolus) stored at 2°C and 10°C. Changes in

The Images in an immersive head‐mounted display (HMD) for virtual reality provide the sole source for visual adaptation. Thus, significant, near‐instantaneous increases in luminance while viewing an HMD can result in visual discomfort. Therefore, the current study investigated the luminance change necessary to induce this discomfort. Based on the psychophysical experiment data collected from 10 subjects

Color vision is an important part of visual processing and as such, it often needs to be evaluated in the pediatric population. The information on a child's color vision status can often be a very important additional clue in establishing the correct clinical diagnosis. The basic principles of color vision are discussed in this review, as well as congenital and acquired color vision deficiencies. The

It is widely believed that children will choose furniture that has the same color as their preferred color. Furthermore, for different categories of furniture, the color they preferred for furniture is consistent. A study of 508 adolescent Chinese children between the ages of 12 and 16 has been carried out to explore whether color preference influences their choice of furniture when they are provided

The main aim of this study is to examine the effect of area on color harmony in simulated interior spaces. The secondary aim of the study is to investigate how the term color harmony is defined and the link between color harmony and related terms used to define it. These terms can explain why a color scheme is evaluated as harmonious. Four sets of three‐color combinations created by using the hues

The visual sensation of gloss is built on cues deduced from the interaction between light, surfaces sunder evaluation, and surrounding conditions. Gloss is a second‐order attribute of the visual appearance, this means that its perception is not directly encoded on biological sensors but constructed from the global scene in the field of view of the observer. It is then a complex quantity to measure

The lightfastness of prints is an important property for assessing their print stability. The objective of this study is to determine the lightfastness rate of printed films due to long‐time exposure by applying artificial neural network (ANN). Package printing is gradually becoming extremely important because its color and quality increase the marketability of the product. Sometimes it has been observed

Taste is an acquired phenomenon. The tastes of colors are related to people's perceptions and assumptions, as well as their personal experiences. In other words, there is a meaningful correlation between taste and color. However, this correlation requires extensive investigation before general patterns of taste perceptions can be determined. In addition, multiple studies of a range of different populations

This research shows the effect of simultaneous contrast on a design solution that generates it, and it also shows how its manifestation affects the shift of perception attributes of the observer's color. In the conducted research, 55 subjects had to harmonize the primary stimuli from the reproduction obtained with the help of digital printing technology, with the primary stimuli presented on two computer

The detailed examination of low contrast image is a challenging issue. Thus, it makes difficult for the viewer to bring out the detailed features of the image. Histogram equalization (HE) is an efficient way to intensify the contrast of images. However, classical HE techniques result in immoderate intensification. Hence, an efficient contrast enhancement algorithm called quadrant dynamic clipped HE

Despite having difficulties in discriminating colors, individuals with a congenital color vision defect (CVD) sometimes identify colors correctly. One explanation for their correct use of the color name could be the context in which the color is used. In North America, how context influences the use of color names can be illustrated using the pedestrian signal light, where the color of the light indicating

CAT02, the most widely used chromatic adaptation transform to characterize the chromatic adaptation mechanism in the human visual system, includes a factor D to characterize the degree of chromatic adaptation. This factor, however, is only determined by the luminance level of the adapting field and surround. This study was designed to investigate how the change of adapting chromaticities and the simultaneous

Recently, Cao et al proposed an adaptive weighting method for the training samples for reflectance reconstruction according to both colorimetric and spectral reflectance similarities for a given vector defined by tristimulus values. It was shown the Cao et al method outperforms the other methods including the regression estimation method in terms of multiple evaluation criteria. In this article, motivated

Image edge detection based on low‐level feature is usually performed on gray‐scale images. Some methods have been developed for edge detection on colour images based on low‐level feature, but they are not consistent with human colour perception. This research provides a new algorithm for edge detection based on the “HyAB” large‐colour‐difference formula. This algorithm uses Sobel operators for gradient‐magnitude

A method is proposed to generate categorical colour observer functions (individual colour matching functions) for any field size based on the CIE 2006 system of physiological observer functions. The method combines proposed categorical observer techniques of Sarkar et al with a physiologically‐based individual observer model of Asano et al and a clustering technique to produce the optimal set of categorical

Color therapy, healing through color, supposedly works through the physical exposure to color. In two studies, we assessed stress and anxiety reduction after color exposure using a commercially available relaxation‐through‐color routine. Participants either completed the routine by looking at the accompanying color disks or at a white patch. In study 1 (longitudinal), 60 participants completed the

Since smokers are becoming younger and younger, it is necessary to curb the tobacco epidemic at a younger age to prevent the devastating damage caused by tobacco products to future generations. This study focuses on the color schemes of cigarette packaging. It aims to find out color schemes of teenage consumers' disgust and apply them to cigarette packaging, which ultimately reduces the desire of purchasing

Image color clustering is a basic technique in image processing and computer vision, which is often applied in image segmentation, color transfer, contrast enhancement, object detection, skin color capture, and so forth. Various clustering algorithms have been employed for image color clustering in recent years. However, most of the algorithms require a large amount of memory or a predetermined number

Versatile smart packages provide information on the freshness of the content and help protect the content from microorganisms. In this sense, in this study both natural antimicrobial properties and pH sensitive natural dyes were obtained from red beet. Inks were prepared and printed using this dye and their suitability for smart packaging was investigated. For this purpose, red beet was cut into small

With the continuous progress of urbanization, China's urban color planning has begun to receive attention, but there are still many problems in the quality of color environment. In order to clarify further the urban color positioning of our country, the detailed urban color planning objectives are set up, and the opinions of residents with different attributes are included in the consideration scope

This work is concerned with the prediction of visual colour difference between pairs of palettes. In this study, the palettes contained five colours arranged in a horizontal row. A total of 95 pairs of palettes were rated for visual difference by 20 participants. The colour difference between the palettes was predicted using two algorithms, each based on one of six colour‐difference formulae. The best

Although an image can consist of myriad different colors, due to the limitations of the human visual system and the mechanism of selective visual attention, only a limited number of them are prominent, that is, they stand out or are noticeable at first sight. In this article, a framework for building a model for extracting image prominent colors based on machine learning is presented. The model is

This study aims to explore the specific impact of a color's hue, saturation, and brightness value on people's evaluation, behavior, and emotions in the public space of existing shopping malls. Following a field investigation, color composition and distribution characteristics in the public spaces of shopping malls are summarized. In the real scenes, the hues of colors are mainly warm colors, with some

In this study, a viscose/polyester fabric was printed by disperse and vat dyes to match the reflectance characteristics of the NATO black and green hues with forest environment in the visible/near‐infrared (Vis‐NIR) reflection spectrum. The black and activated carbon nanoparticles were also added to the printing paste to match the reflectance of hues. Color components and Vis‐NIR reflective behavior

Variability in object appearance is common in everyday experience and this variability can generally be attributed to the relationships between viewing conditions and the composition of an object's spectral reflectances. This paper proposes that objects, illuminants, and observers can be evaluated using a Wpt (Waypoint) shift manifold (WSM), which is defined as a set of Wpt points associated with one

Color, as one of the most important dimensions of vision, plays a key role in place identity and people's experience in the environment. This study aims to investigate people's visual experience of seasonal color change in the environment, and proposes an approach for analyzing and communicating environmental colors by combining color analysis and information visualization. Employing crowdsourced Flickr

Polychrome alabaster carvings, representing religious scenes, constitute England's major contribution to European mediaeval sculpture. During the period between 1350 and 1550, large number of alabaster carvings were produced in the Midlands. Despite their massive destruction during the English Reformation (ca.1534), more than 2500 of them still survive, either legally exported or sold clandestinely

The cover image is based on the Research Article Development of an image evaluation method for skin color distribution in facial images and its application: Aging effects and seasonal changes of facial color distribution by Kumiko Kikuchi et al., https://doi.org/10.1002/col.22469.

It is common practice in statistics to test the equality of two population means using, for example, the Student's t test, in the univariate case, or the Hotelling's T2 Test in the multivariate case. However, tests on the equality of population means are not well developed for testing the difference between two populations of color measurements. Methods for analyzing populations of spectral reflectance

Small, supra‐threshold color differences are typically described with Euclidean distance metrics, or dimension‐weighted Euclidean metrics, in color appearance spaces such as CIELAB. This research examines the perception and modeling of very large color differences in the order of 10 CIELAB units or larger, with an aim of describing the salience of color differences between distinct objects in real‐world

A precise and shared description of gemstones color could greatly help their classification and market evaluation, and the key to develop an efficient color evaluation system for gemstones is the creation of a common descriptive language and assessment method. Nowadays, there is a lack of standards for the determination of color of gemstones, and traditional color assessment is exclusively based on

Psychophysical experiments of colour appearance, in terms of lightness, colourfulness, and hue, were conducted outdoors and indoors to investigate whether there was any difference in colour appearance between outdoor and indoor environments. A panel of 10 observers participated in the outdoor experiment, while 13 observers took part in the indoor experiment. The reference white had an average luminance

The color of mineral pigments changes obviously with their particle size. However, how the particle size of these mineral pigments affects the color of the mineral pigment color block remains unclear. Based on optical principles and the physical properties of mineral pigment particles, our analysis found that changes in the particle size not only nonlinearly affect the behavior of light at the first

Blue colors were sparsely used in the first colored Japanese ukiyo‐e prints but became predominant during the 19th century, mainly due to the integration of the synthetic Prussian blue in the palette of the printers around 1830. For a long time, researchers have assumed that the traditional Japanese organic blue colorants such as indigo were substituted by cheaper Prussian blue. Some analytical studies

Metamer mismatching occurs in both the human visual system and digital imaging systems. Increasing the number of sensors in digital imaging systems is an efficient method to reduce the degree of metamer mismatching. This study investigates the number of sensors that are needed for the digital imaging systems to have a similar ability to the human sensor system in distinguishing colors from the perspective

In this article, we present an evaluation method for the skin color distribution in the face area. Unlike previous methods that extract a specific area, our method subdivides the entire face into small regions and analyzes detailed, per‐frame textures. Our evaluation method for skin color distribution is based on facial feature points and includes segmentation that takes into account the facial skeleton

Generating high‐quality sequential color schemes for maps is challenging for most mapmakers. This article presents a harmony‐based approach for automatically generating sequential color schemes for maps. The proposed approach consists of two steps: (a) color harmony quantification for sequential color schemes on maps and (b) color scheme generation using quantified color harmony factors. The approach

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

The outcome of a print in production run plays a crucial role in commercial and packaging printing. In the growing packaging industry, colorfulness and saturated prints with high chroma attract the eye of the consumer. The design and layout of a packaging carton comprise of images that consist of halftones in the print process, which demand attractiveness and visibility using bright colors. In this

This study describes the lightfastness properties of printed foil samples due to long‐time exposure. Lightfastness is an important property for any kind of print products to assess their print stability. The fastness properties of prints can be described in terms of print durability and image stability. It may also be used for verification of printed expiry date and authenticity or validity of the

The overall objective of this study is to confirm the method of determining the accuracy of Kubelka‐Munk reflectance theory (KMRT) for composite materials after undergoing aging unrelated to surface exposure. The specific aims of this study include comparisons of optical characterizations for two dental resin composite materials before and after aging in darkness. Aging of five shades of two nanohybrid

This study investigated the effect of contrast in neutral‐, warm‐, and cool‐colored spaces on spatial memory. Spatial memory was measured in terms of architectural scale and recollection of architectural elements and furniture. Participants (N = 114) viewed a short virtual simulation video of a residential studio and were asked to sketch a map of the architectural elements on distributed grid paper

The objective of this study is to determine if men would follow the “red effect” when choosing colors for women to wear on a date, and also to determine if the colors that men would wear when going on a date would be the same as the colors that females (their date) would wish them to wear. A set of psychophysical data was generated from this experiment, where participants were asked to rank a set of

In this work, we built a multi‐primary display model based on the new quantum dots (QD) technology to enlarge the display color gamut. In this way, first the emission spectral radiance curves of the three RGB channels of a commercial QD display were fitted to a four‐parameter function. From this modeling, it is possible to gain new theoretical color primaries by selecting new spectral peaks (cyan,

The aim of this study was to investigate the impact of signboard‐building color combinations on color harmony and legibility. Two hundred and three participants rated 54 signboard‐building color combinations against two scales of color harmony and legibility. In this article, the terms “brick,” “stone,” and “glass” refer to three types of building exteriors used in the experiment (ie, brick masonry