Automatic detection of layout of color yarns of yarn‐dyed fabric. Part 3: Double‐system‐Mélange color fabrics

Automat layout detection of color yarns is necessary for weaving and producing processes of yarn‐dyed fabrics. This study presents a novel approach to inspect the layout of color yarns of double‐system‐mélange color fabrics automatically, which is Part III of the series of studies to develop a computer vision‐based system for automatic inspection of color yarn layout for yarn‐dyed fabrics. The inspection of single‐system‐mélange color fabrics has been realized in Part I of the series of studies. Integrating the projection‐based region segmentation method proposed in Part I and the FCM‐based stepwise classification method proposed in Part II, the proposed approach is composed of three steps: (1) fabric region segmentation, (2) fabric region selection, and (3) layout of color yarns recognition. In the first step, the fabric regions are segmented by the projection‐based region segmentation method. In the second step, the reasonable fabric regions are selected by analyzing their color histograms and comparing their weft color's frequency. In the third step, the layout of color yarn is recognized by the FCM‐based stepwise classification method, and the precise layouts of color warps and wefts are produced. The experimental analysis proved that the proposed method can recognize the layout of color yarns of double‐system‐mélange color fabrics correctly by testing four different color fabrics and three pieces of same yarn‐dyed fabrics. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 250–260, 2017     

Application of Ultrasonic Measurement on Small‐Sized Ceramic Sample

The longitudinal and transverse wave velocities of polycrystalline MgO were successfully measured simultaneously and five types of elastic moduli, the Debye temperature, and the Grüneisen parameter were evaluated as functions of temperature from 298 to 1764 K. An aluminum foil was used as a couplant between the MgO specimen and waveguide. Both acoustic waves were successfully propagated into the specimen through the solid and liquid aluminum layers. In particular, no influence of melted aluminum foil on the acoustic wave velocities was observed. With increasing temperature, the Young's, shear, and bulk moduli decreased monotonically and the Grüneisen parameter and Poisson's ratio increased monotonically, which indicated a decrease in the ionic bonding strength. The Debye temperature decreased almost linearly with increasing temperature, which showed the effect of thermal expansion. Although previous investigators concluded that the Grüneisen parameter was almost independent of temperature, our data showed an obvious gradual increase in this parameter with temperature. In addition, our results implied the possibility of an abrupt increase in the Grüneisen parameter at temperatures less than 400 K. The slope of the Lamé parameter–temperature plot was almost zero over the entire investigated temperature range. On the basis of three‐dimensional volume‐nonpreserving shear, this behavior was interpreted as being caused by interlocking associated with the network of short Mg–O bonds.     

Measuring linear density of threads in single‐system‐mélange color fabrics with FCM algorithm

According to the color yarns in the fabric, the fabrics can be divided into three categories: solid color fabrics, single‐system‐mélange color fabrics, and double‐system‐mélange color fabrics. The density of solid fabrics can be inspected with gray‐projection method or Fourier analysis method. But the methods cannot be applied to yarn‐dyed fabrics directly. A method for detecting the density of single‐system‐mélange color fabrics will be discussed in this article. By analyzing the pattern and color characters of single‐system‐mélange color fabrics, fuzzy C‐means algorithm is proposed to classify the colors in the fabric image based on CIELAB color space first. With the color segmentation results, the fabric can be divided into different blocks. The yarns can be located in different blocks with different average gray‐levels, and then the number of yarns can be counted in each block. The linear density of threads can be obtained by counting the yarns in a unit length finally. The experiment proved that the algorithm proposed in this study can inspect the density of single‐system‐mélange color fabric successfully. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 456–462, 2013     

Adequateness of a newly modified opponent‐colors theory

Two features of a newly modified opponent‐colors theory are examined for correctness: (1) The perceived chroma of pure color is different for different hues. This was confirmed by using Ikeda's UCS (Uniform Color Scales) formula and also by the maximum Munsell Chroma Values for different hues. (2) Chromatic colors with the same values of whiteness, blackness, grayness, and perceived chroma have the same perceived lightness and chromatic tone regardless of hue. This was confirmed by a theoretical analysis and observations of the color samples in the Practical Color Co‐ordinate System (PCCS) developed in Japan. Chromatic tone, a complex concept of object colors, is clarified. The structure of the newly modified theory and its corresponding color space were confirmed by observation of object colors. Furthermore, it was found effective for developing a color‐order system and its corresponding standard color charts to the modified theory. © 2003 Wiley Periodicals, Inc. Col Res Appl, 28, 298–307, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10164     

Inkjet printing effects of pigment inks on silk fabrics surface‐modified with O2 plasma

Without any preprocessing, silk fabric has lower ability to hold on water due to the smooth morphology of silk fibers. Therefore, patterns directly printed with pigment inks have poor color yields and easily bleed. Plasma surface‐treatment of silk fabric was carried out in an oxygen atmosphere under different experimental conditions. The samples were printed with magenta pigment ink after treatment. The results showed that the optimum treatment conditions we obtained were exposure time of 10 min at a working pressure of 50 Pa and a working power around 80 W. At such conditions, surface‐modified silk fabrics could obtain the effects of features with enhanced color yields and excellent pattern sharpness. Atomic force microscope images indicated that low‐temperature oxygen plasma initiated modifications to the surface of silk fiber with more grooves. Dynamic contact angle analysis showed that the hydrophilicity of silk fiber was remarkably improved after pretreatment with plasma. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Correlations between color attributes and children's color preferences

This study examined the role of color attributes (lightness and saturation) on children's color preferences for interior room colors. It also investigated children's most preferred colors among each of the five major hue families in the Munsell color system using scale‐models. Previous color preference studies have typically been done with small color chips or papers, which are very different from seeing a color applied on wall surfaces. A simulation method allowed for investigating the value of color in real contexts and controlling confounding variables. Forty‐five color samples were displayed on scale‐models to 63 children ages 7–11 years old. This study identified children's most preferred colors among each of the five major hue families in Munsell color system. It also demonstrated that saturation was positively correlated with children's preferences in the red, green, blue, and purple hue families. In the yellow hue family, interestingly, lightness has a positive correlation with preferences. Children's gender differences were found in that girls prefer red and purple more than boys. These findings lead to color application guidelines for designers to understand better color and eventually to create improved environments for children and their families. © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 452–462, 2014     

Visible‐near infrared concealment of cotton/nylon fabrics using colored pigments and multiwalled carbon nanotube particles (MWCNTs)

To match the reflectance profile of desert colors including dark brown, light brown and olive green in the visible‐near IR (Vis‐NIR) bands, five selected colored pigments were utilized to print woven cotton/nylon fabrics. Multi‐walled carbon nanotube particles (MWCNT's) were also added to some of the printing pastes. The reflectance of printed fabrics was evaluated by using spectrophotometric technique. The effect of adding MWCNT's, on washing; light and crocking fastness alongside with colorimetric values of printed samples was evaluated. Furthermore, the water absorption time was measured in order to determine wettability of each printed sample. The results demonstrated that the presence of MWCNT's in concentration range of 0.04–0.12 g kg^?1 in printing formulations was found to cause considerable decline in Near Infrared (NIR) reflectance while a surprising increase in visible reflectance of samples was observed. Color characteristics of printed fabrics were noticeably changed even at concentrations as low as 0.12 g kg^?1 MWCNTs in printing formulations. Presence of MWCNTs in printing formulations was found to cause a significant increase in wetting time of samples. Also, the results indicated that air permeability of printed samples containing MWCNT's were higher than samples printed with no MWCNTs. Phenomena imposed by MWCNT's presence on pigment printed samples showed very good fastness levels in crocking, washing and light fastness tests. In dark brown sample, adding MWCNTs to the pigment printing pastes could tune the overall reflectance in order to match the standard reflectance profile accepted for use in concealment color of desert areas. © 2013 Wiley Periodicals, Inc. Col Res Appl, 40, 93–98, 2015     

A study of color conspicuity for ease‐of‐use inference in visualization

Novice designers of visualizations need support to find easy‐to‐use color schemes for visualizations. This article introduces a method of conspicuity inference for a color selection support system that is applicable to a wide variety of visualizations. In previous research, data on color conspicuity by computer GUI interface were collected by having subjects adjust the relative sizes of two figures on a ground in order to find conspicuity balance. This article outlines a new conspicuity inference system, which uses a neural network to produce a color conspicuity value from the system RGB values of two figures and a potential ground. The output value is the ideal relative area of the two figures. This value is applied to visualization designs by weighting each conspicuity value with a ground coefficient, the relative size of every color in a design. Color selection and evaluation experiments show a significant relationship of conspicuity balance, as inferred by this system, for subjective ease‐of‐use evaluation scores for 200 novice designs. Topics for future research include developing the system's characteristically simple parameters within the limited scope and integrating conspicuity balance with other factors such as visibility, discriminability, and color harmony. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 74–82, 2002; DOI 10.1002/col.10033     

Automatic detection of layout of color yarns of yarn‐dyed fabric. Part 1: Single‐system‐mélange color fabrics

To recognize the layout of color yarns of single‐system‐mélange color fabric automatically, a novel FCM‐based stepwise classification method is proposed in this article. This method consists of three main steps: (1) warp yarn segmentation, (2) weft color recognition, and (3) the layout of color warps recognition. In the first step, the yarn segmentation method based on mathematical statistics of subimages is adopted to localize warp yarns preliminarily; and then the segmentation results of warp yarn are corrected by misrecognized‐boundary remove and missing‐boundary interpolation. In the second step, the weft color is extracted based on RGB color histograms of whole fabric image. In the third step, the pixels in each warp yarn are classified into two clusters by fuzzy C‐means clustering (FCM) algorithm in CIELAB color model separately, and the preliminary recognized layout of color warps is obtained. All warp colors are clustered by FCM algorithm in CIELAB color model again and the precise layout of color warps is output. The experimental and theoretical analysis proved that the proposed method can recognize the layout of color yarns of single‐system‐ mélange color fabrics with satisfactory accuracy and good robustness. © 2015 Wiley Periodicals, Inc. Col Res Appl, 40, 626–636, 2015     

Preparation of water‐repellent silks by a reaction with octadecenylsuccinic anhydride

Silk fibers and membranes were acylated with octadecenylsuccinic anhydride (ODSA) at 75°C for different times. Swelling [N,N‐dimethylformamide (DMF) and dimethyl sulfoxide (DMSO)] and nonswelling (xylene) solvent media were used for the reaction. Silk membranes that reacted in DMF or DMSO displayed faster reaction kinetics and attained higher weight‐gain values than fibers. The effect of the solvent on the reaction yield was in the following order: DMSO > DMF ? xylene. The Fourier transform infrared spectra of acylated silk samples showed the characteristic absorption bands of the anhydride at 2990, 2852, 1780–1700, and 1170 cm^?1. The intensity of the latter band, which increased linearly with the weight gain, was used as a marker for evaluating the reaction kinetics of the samples acylated in the nonswelling medium. The moisture regain and water retention of silk fibers acylated with ODSA decreased significantly, regardless of the solvent system used. Accordingly, the water repellency increased. Acylation induced an increase in the thermal stability of the silk fibers and membranes. Fine particles adhering to the surfaces of the silk fibers acylated in xylene were detected by scanning electron microscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 324–332, 2003     

Automatic detection of layout of color yarns of yarn‐dyed fabric. Part 2: Region segmentation of double‐system‐Mélange color fabric

To detect the layout of color yarns automatically, a novel projection‐based fabric segmentation method is proposed to segment the double‐system‐mélange color fabric into several regions, which can be seen as single‐system‐mélange color fabrics. This method consists of five main steps: (1) yarn skew detection, (2) fabric image projecting, (3) projection curve smoothing, (4) variance curve calculating, and (5) curve peak confirmation. Based on the acquisition fabric image, the skew angles of warp and weft yarns are detected by Hough transform first. The projection curves of L, a, and b channels in Lab color model are generated and smoothed by Savitzky–Golay filter. The variance curves of L, a, and b are then calculated, and the peaks corresponding to the regional boundaries in each curve are detected. The regional boundaries are confirmed by synthesizing the curve peaks of L, a, and b. The experimental and theoretical analysis proves that the proposed method can segment the double‐system‐mélange color fabric into regions with satisfactory accuracy and good robustness. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 626–635, 2016     

Improving the photostability of bleached silk without reducing its whiteness

Bleached silk is rapidly yellowed by exposure to the ultraviolet radiation present in sunlight. The conventional application of a water‐soluble hydroxyphenyl benzotriazole ultraviolet absorber (such as UVFast W) to bleached silk reduces its rate of photoyellowing but has a negative impact on the whiteness of the bleached silk, largely cancelling out the improvements in whiteness achieved during bleaching. Therefore, a series of bleaching processes and aftertreatments using UVFast W on silk were investigated, with the measurement of reflection spectrum, whiteness, yellowness, and strength before and after exposure to ultraviolet radiation. The results show that whiteness of silk treated by oxidation–reduction double bleaching can be increased, and the whiteness of double‐bleached silk with 4% UVFast W aftertreatment was even slightly higher than that of the hydrogen‐peroxide‐bleached silk. After ultraviolet irradiation, double‐bleached silk samples with 4% UVFast W treatment resulted in both the highest whiteness and optimum photostability by comparison with unbleached standard silk and hydrogen‐peroxide‐bleached silk samples with and without 4% UVFast W treatment, and its strength difference was superior to the samples, except for standard silk with 4% UVFast W treatment after exposure to UV radiation for 18 h.     

The Development of Fibers That Mimic the Core–Sheath and Spindle‐Knot Morphology of Artificial Silk Using Microfluidic Devices

Spider and silkworm produce diverse silk fibers from spinning dopes through smart spinnerets. Spider's capture silk is composed of core thread and periodic spindle‐knots, while silkworm silk consists of fibroin core and sericin outer layer. To mimic the morphologies of natural heterostructured silks, artificial fibers are dry‐spun using a multichannel microfluidic chip, served with a highly viscous core solution of regenerated silk fibroin and low viscosity sheath solution of sericin. Silk fibers with core–sheath, groove, and spindle‐knot structures are obtained by controlling the flow rates and viscosities of the two microfluids depending on the laminar flow, Kelvin–Helmholtz instability, or Plateau–Rayleigh instability.     

The first color education in Japan

The Meiji era (1868–1912) stands out as a period of radical modernization in Japan. For this reason, the Meiji Government paid special attention to the introduction of Western culture and civilization into modern Japanese society. Irozu (Color Chart) as the first attempt at color education in Japan resulted from one of these attempts at modernization. Iro-zu was a direct copy of Willson's Charts for object lessons which were prevalent in the United States at that time. Willson's Charts themselves had been substantiated by color science in the Western world, especially the works of the English chemist Field and the French chemist Chevreul. On the contrary, Iro-zu education almost abandoned the scientific meanings which Willson's Charts carried. According to the reformation of the educational system in 1879, Iro-zu education was gradually reduced. Though Iro-zu education lasted only five or six years, it has great importance as it marks the beginning of color education in Japan.     

Biodegradable Laminates Based on Gelatin, 2

Compression moulded laminates based on a gelatin or a blended gelatin/starch matrix reinforced by fabrics (linen or silk) were prepared. Three linen or five silk sheets with a powdered matrix between them were compression moulded at 180 °C for several minutes. In addition, cross‐linked laminates were obtained by using methylenedi(p‐phenyl) diisocyanate as a cross‐linking agent expected to obtain an improved integrity between the matrix and the reinforcing elements. In this way a total of ten uncross‐linked and cross‐linked samples differing in the type of the matrix (gelatin or gelatin/starch) and the type of the reinforcing element (linen or silk), both uncross‐linked and cross‐linked, were obtained. All samples were characterized by means of mechanical testing (Young's modulus, tensile strength, elongation at break and impact strength), as reported in Part 1 of this study. In the present Part 2, the same ten samples were artificially weathered, and changes in both the mechanical properties and the specific wear rate with aging time were followed. It was found that the majority of the mechanical parameters generally became worse with aging time; only the Young's modulus and the tensile strength remained on the same order of magnitude for all laminates. The linen reinforced laminates showed much higher values of the deformation at break, the impact strength and the wear resistance in comparison to the silk reinforced laminates. A similar tendency was found for the sliding wear tests against smooth steel counterparts. A reinforcement of gelatin or gelatin/starch with linen was much more effective in improving the laminate wear resistance than a reinforcement with silk. In addition, the abrasion resistance of neat gelatin was found to be much higher than that of the gelatin/starch blend, as evaluated by the Taber index.

Dependence of Young's modulus on aging time for the neat matrix samples (gelatin and gelatin/starch) and the compression moulded laminates reinforced with fabrics.     

Dye behavior of cationically treated silk

To increase the performance of silk fabrics, especially their dyeability, a cationic modifying agent, 3‐(trimethoxysilyl) propyl dodecyl dimethyl ammonium chloride (HSQA), was prepared in our laboratory. The dye behavior of the cationized silk was examined with five leveling‐type acid dyes. Better color shades and good washing fastness were achieved after silk was cationized by HSQA, and it was possible to dye silk under neutral conditions at 70°C. The equilibrium adsorption isotherm and kinetic properties of the cationized silk dyed with CI Acid Orange 7 were investigated. The adsorption of CI Acid Orange 7 onto the HSQA‐cationized silk was also in good agreement with the Langmuir isotherm, with an enthalpy and an entropy of −20.13 kJ/mol and −30.06 J/mol K respectively. A pseudo‐second‐order kinetic model agreed well with the dynamic behaviors for the adsorption of CI Acid Orange 7 onto the cationized silk under neutral conditions, with the activation energy decreasing from 61.87 to 53.32 kJ/mol. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Color space and its divisions

A synthesis of the author's recent work on color‐order systems and color‐difference evaluation is provided in context of current knowledge and practices. The development of a colorimetric model is demonstrated using Munsell “Celtic crosses” as a model of perceptual space. Issues surrounding color‐matching functions, unique hues, the Helmholtz–Kohlrausch effect, and lightness and chroma crispening are addressed, as is the difficulty of reconciling a difference‐based hue, chroma, lightness model with an Euclidean model. A new lightness scale and treatment of lightness crispening is proposed. The results indicate that, despite problems, relatively simple modified opponent‐color models provide good accuracy in predicting color‐order system and supra‐threshold small color‐difference data. © 2001 John Wiley & Sons, Inc. Col Res Appl, 26, 209–222, 2001     

Evaluation of performance of various color‐difference formulae using an experimental black dataset

The objective of this study was to develop a specific visual dataset comprising black‐appearing samples with low lightness (L* ranging from approximately 10.4 to 19.5), varying in hue and chroma, evaluating their visual differences against a reference sample, and testing the performance of major color difference formulas currently in use as well as OSA‐UCS‐based models and more recent CAM02 color difference formulas including CAM02‐SCD and CAM02‐UCS models. The dataset comprised 50 dyed black fabric samples of similar structure, and a standard (L*= 15.33, a* = 0.14, b* = ?0.82), with a distribution of small color differences, in ΔE^*_ab, from 0 to approximately 5. The visual color difference between each sample and the standard was assessed by 19 observers in three separate sittings with an interval of at least 24 hours between trials using an AATCC standard gray scale for color change, and a total of 2850 assessments were obtained. A third‐degree polynomial equation was used to convert gray scale ratings to visual differences. The Standard Residual Sum of Squares index (STRESS) and Pearson's correlation coefficient (r), were used to evaluate the performance of various color difference formulae based on visual results. According to the analysis of STRESS index and correlation coefficient results CAM02 color difference equations exhibited the best agreement against visual data with statistically significant improvement over other models tested. The CIEDE2000 (1:1:1) equation also showed good performance in this region of the color space. © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 589–598, 2014