Color Of Samples Research Articles

Characterization of historical minai and colorful luster glaze ceramics, using ionoluminescence technique

Some historical minai and colorful luster glaze ceramic samples were investigated by means of ionoluminescence technique. The complementary ion beam analysis techniques RBS and PIXE were employed to reveal their elemental compositions and depth profiles. The samples were discovered in the historical site of Tappeh Ghale in Iran, which dates back to 12th century. The ionoluminescence spectra of the samples reveal the strong dependence of the luminescence bands, mostly originating from oxygen-deficient centers, on the elemental compositions of the glaze samples. It is inferred that most of the luminescence centers likely have been created during the formation process of tin-opacified lead-rich glazes. The demonstrated capabilities of ionoluminescence in the current work, confirm the possibility of its application for fast and non-destructive characterization of historical glaze samples.

Study on multi-color emotion based on fashion color in 2019

PurposeThe purpose of this paper is to derive the relationship between color schemes and emotion to serve for designers and consumers.Design/methodology/approachThe three attributes of hue, brightness and saturation of the selected sample color are analyzed, and the Semantic Differential (SD) method is used for the emotional evaluation of color schemes, and data obtained from the emotional evaluation of color schemes is analyzed by using Excel software for mean statistics and SPSS software for factor analysis and cluster analysis.FindingsFrom the results of the factor analysis, three main factors that affect the feeling of the color scheme can be extracted: “personality”, “gender” and “fashion”. Color emotions can be achieved by changing the level of color saturation and brightness, the cold and warmth of the hue and the way of color combination.Research limitations/implicationsSince it takes a long time to fill out the questionnaire, the number of valid questionnaires collected is a little less and the research data is limited. In addition, some problems are not taken into account such as geography and so on, so the results of the statistical analysis are not very precise and further research is needed.Practical implicationsIt can provide information of emotional color schemes for designers and consumers, and based on the SD method, an emotional color matching questionnaire is designed and statistical analysis is conducted to establish the relationship between emotion and color schemes.Originality/valueBased on the fashion color sample and color harmony theory, the color matching rules and color matching schemes are designed independently.

An Efficient Algorithm for Luminance Optimization in Chroma Downsampling

The classical chroma subsampling involves downsampling chrominance components (U and V) while maintaining the luminance component (Y). Recently, a study has attempted to change Y for the chroma-subsampling process, and improved results in the reconstructed image quality are obtained. However, computational complexity remains an issue because the study examines all the candidates in the determined range for minimal pixel distortion for the modified Y; the complexity can be high if the range is large. In this study, we reduced the candidate number to seven at most, which is mathematically optimized. Boundary points for in-the-range red, green, and blue (RGB) values are first decided, followed by the determination of the intervals that concatenate the entire curve (at most seven intervals). Each interval belongs to one of the seven sub-cases of different linear combinations of individual curves. The optimal solution (modified Y) for each sub-case is derived, which is in highly efficient form. Compared with the existing method, the proposed fast method ensures that the image quality is preserved, while the number of search candidates is reduced by 61.30%-69.19% on average, and the computational time of the process is reduced by 31.39%-58.97%, thereby demonstrating an efficient performance.

Simplification on Cross-Component Linear Model in Versatile Video Coding

To improve coding efficiency by exploiting the local inter-component redundancy between the luma and chroma components, the cross-component linear model (CCLM) is included in the versatile video coding (VVC) standard. In the CCLM mode, linear model parameters are derived from the neighboring luma and chroma samples of the current block. Furthermore, chroma samples are predicted by the reconstructed samples in the collocated luma block with the derived parameters. However, as the CCLM design in the VVC test model (VTM)-6.0 has many conditional branches in its processes to use only available neighboring samples, the CCLM implementation in parallel processing is limited. To address this implementation issue, this paper proposes including the neighboring sample generation as the first process of the CCLM, so as to simplify the succeeding CCLM processes. As unavailable neighboring samples are replaced with the adjacent available samples by the proposed CCLM, the neighboring sample availability checks can be removed. This results in simplified downsampling filter shapes for the luma sample. Therefore, the proposed CCLM can be efficiently implemented by employing parallel processing in both hardware and software implementations, owing to the removal of the neighboring sample availability checks and the simplification of the luma downsampling filters. The experimental results demonstrate that the proposed CCLM reduces the decoding runtime complexity of the CCLM mode, with negligible impact on the Bjøntegaard delta (BD)-rate.

FI‐GAN: fewer iterations GAN for rapid synthesis controllable realistic images

Conditional generative adversarial networks (GANs) have led to considerable improvements in the task of conditional image generation. However, there are still some problems, including the low definition of generated images, mode collapse, gradient disappearance and slow convergence, which need to be solved. In this study, the authors proposed a novel conditional GAN model, fewer iterations GAN (FI-GAN), that requires fewer iterations to generate controllable and realistic images. First, to improve the performance of feature extraction of the discriminator and data distribution fitting of the generator, two residual blocks are added into the discriminator and generator. Then, two new loss functions, including quality and category loss functions for both the discriminator and generator, are designed to enhance the details and distinguishability of the generated images. Finally, to avoid mode collapse and improve the convergence, the Wasserstein distance is used as the quality loss function. With the CIFAR-10 and large scene understanding datasets, FI-GAN can generate delicate and diverse colour samples with fewer iterations. It achieved better performance evaluated by three objective criteria, the inception score, Frechet inception distance and kernel maximum mean discrepancy, compared with four methods of conditional GAN.

Compression artifacts reduction with multiscale tensor regularization

We study a multiscale tensor regularization based JPEG decompression artifact removal in digital images. Structure tensor eigenvalues based robust edge map is used within a variable exponent regularization. Variational constrained minimization which combines data fidelity driven by color subsampling and discrete cosine transformation operator is utilized. Experimental results across different compression levels and with various error metrics indicate our proposed method obtains high quality results on cartoon/clip-art and LIVE1 natural image databases.

Image-Based Measurement of Structural Color using Spectral Camera

We perceive structural colors by optical phenomena such as light interference and diffraction caused by a fine structure of the object surface. One of the characteristics of structural colors is that a wavelength distribution of light changes depending on an incident angle of a light source and a viewing angle. Generally, for color evaluation and reproduction, it is required to acquire reflection characteristics of objects. Therefore, BRDF (Bidirectional Reflectance Distribution Function) is often used as a function that represents reflection characteristics depending on incident and viewing angles. In this study, we measured BRDF of structural colors based on a method to acquire image-based material reflection characteristics using a spectral camera. The measurement was performed by aligning an optical axis of a spectral camera with a structural color sample and changing an irradiation angle of a light source. Reflection characteristics were represented by using a radiance factor, which was a ratio between a spectral radiance of white material and that of structural color. From measurement results, we confirmed an angle-dependent radiance factor. Finally, based on a measured spectral radiance of a structural color sample, we spectrally reproduced the structural color using a spectral projector based on model fitting of spectral data.

Testing the Cross-Cultural Generality of Hering's Theory of Color Appearance.

This study examines the cross‐cultural generality of Hering's (1878/1964) color‐opponent theory of color appearance. English‐speaking and Somali‐speaking observers performed variants of two paradigms classically used to study color‐opponency. First, both groups identified similar red, green, blue, and yellow unique hues. Second, 25 English‐speaking and 34 Somali‐speaking observers decomposed the colors present in 135 Munsell color samples into their component Hering elemental sensations—red,green,blue, yellow, white, and black—or else responded “no term.” Both groups responded no term for many samples, notably purples. Somali terms for yellow were often used to name colors all around the color circle, including colors that are bluish according to Hering's theory. Four Somali Grue speakers named both green and blue elicitation samples by their term for green. However, that term did not name the union of all samples called blue or green by English speakers. A similar pattern was found among three Somali Achromatic speakers, who called the blue elicitation sample black or white. Thus, color decomposition by these Somali‐speaking observers suggests a lexically influenced re‐dimensionalization of color appearance space, rather than a simple reduction of the one proposed by Hering. Even some Somali Green‐Blue speakers, whose data were otherwise similar to English, showed similar trends in yellow and blue usage. World Color Survey data mirror these results. These within‐ and cross‐cultural violations of Hering's theory do not challenge the long‐standing view that universal sensory processes mediate color appearance. However, they do demonstrate an important contribution of language in the human understanding of color.

Color discrimination metric based on the neutrality of lighting and hue transposition quantification.

In this Letter, we propose a combined metric for quantifying the color discrimination capability of white light sources. This metric is based on considerations of human visual adaptation to daylight chromaticities, as well as on the concerns of the huge spectral diversity of modern light sources. Two existing metrics, Sneutral (degree of neutrality) by Smet et al. [Opt. Express22, 25830 (2014)OPEXFF1094-408710.1364/OE.22.025830] and Rd (hue transposition among color samples of the Farnsworth-Munsell 100 Hue color vision test) by Esposito and Houser [Lighting Res. Technol.51, 5 (2019)LRTEA90024-342610.1177/1477153517729200] were adopted, and their weights were determined by a meta-analysis of five groups of psychophysical data on color discrimination. The superiority of the newly proposed metric was demonstrated by 16 groups of psychophysical data from eight color discrimination studies, as well as by a comparison with 29 typical color quality metrics and their linear combinations.

Does Eumelanin Oxidation Play a Role on the Photostability of Ethyl Glucuronide in Hair Exposed to Simulated Solar Radiation?

The action of solar radiation on the concentration of the ethanol metabolite ethyl glucuronide (EtG) in 40 hair samples of nonabstinent subjects was investigated. Hair samples of different colors were analyzed before and after irradiation with artificial sunlight under a light dose corresponding to 3 months of sun exposure. After irradiation, an increase of EtG concentration was detected in 55% of the samples ranging from 5% to 141%. In 16 cases, a concentration reduction ranging from -2% to -74% was observed. The measure of the level of pyrrole-2,3,5-tricarboxylic acid (PTCA), a marker of eumelanin oxidation, demonstrated the largest increase in oxidation in light brown hair where the greatest degradation of EtG was observed after irradiation. However, the rise of PTCA in all hair tested was accompanied by increase in EtG concentration in 8/10 samples and by decrease in 2/10, suggesting no correlation between the two markers. To verify if hair structure was modified by light, scanning electron microscopy (SEM) analysis was performed on irradiated hair of different colors and compared with the dark samples. SEM revealed modification of hair structure in all samples showing partial shaft exfoliation and reduction of hair thickness under the treatment with solar radiation.

Colour thresholds of the gingival chromatic space

OBJECTIVETo establish the thresholds of chromatic perception and clinical acceptability of gingival colour according to professional category and in accordance with the perceptibility/acceptability threshold of 50:50 (colour differences that can be perceived/accepted by 50 % of the observers). METHODSA total of 21 different coloured samples made of pink gingiva Heraceram porcelain were used. Dentists (n = 54), dental assistants (n = 56), dental students (n = 126) and participants unrelated to dentistry (n = 116) were asked to identify pairs of samples that appeared identical. In addition, they were asked to indicate the pairs of samples whose colour they considered to be acceptable for use in a dental rehabilitation. A least squares regression was adjusted using an S-shaped curve of the equation y = exp (B0 + B1/x). The adjusted model was used to predict a colour difference value for an acceptability percentage of 50 %. RESULTSThe threshold value for the perception of colour changes in human gingiva varies from ΔEab* 2.3 ± 0.38 units and CIEDE2000 (ΔE00) 1.5 ± 0.28units (dental students) to ΔEab* 2.7 ± 0.43 units and ΔE00 1.8 ± 0.30 units (participants unrelated to dentistry). The threshold of gingival acceptability varies from ΔEab* 2.9 ± 0.43 units and ΔE00 2.0 ± 0.31 units (dental assistants) to ΔEab* 3.6 ± 0.54 units and ΔE00 2.5 ± 0.41 units (dental students). CONCLUSIONFrom the total number of samples, the average threshold of perception for the gingival chromatic space is 3.1 units for ΔEab* and 2.1 units for ΔE00. Moreover, the mean gingival acceptance threshold is 4.1 units for ΔEab* and 2.9 units for ΔE00. These thresholds are similar for all professional categories studied. CLINICAL SIGNIFICANCEThe determination of the perception and acceptability thresholds in the gingival chromatic space are of special relevance for designing the physical shade tabs used in gingival colour guides. The results from this work will aid in selecting optimal gingival colour for patients.

Dyeing of Polyester Fabric with Natural Colorants Extracted from Mahogany (Swieteniamahagoni) Seed Pods

Polyester fabric is usually dyed with disperse dyes which has severe limitations specially toxicity and environmental issues. The aim of the present research is to introduce an ecofriendly dyeing process for polyester fabric with natural dyes. The natural colorants were extracted from mahogany seed pods using the simple acid boiling method. The spectroscopic analysis of the crude extract was carried out by UV and IR spectra of the extracted dyes and illuminated the presence of natural tannins as coloring materials in the crude extract. 10g fabric was dyed in 200cc extracted solution at 130⁰C for 60 minutes in exhaust dyeing method followed by neutralization and soaping. Finally, a light brown dyed fabric was obtained. The dyed fabric exhibited color strength in terms of k/s value of 0.63 (λmax 360nm), lightness of 80.565 and chromaticity value of 12.002 CIE units. Different samples were dyed by fluctuating the dyeing period. The dyeing traits of the dyed materials were judged in terms of their color strength and fatness properties. All testes were carried out following the ISO standards. From the results, it is lucid that the dyed fabric showed acceptable color fastness properties in case of all fastness except color fastness to light. It is observed that dyeing time had profound influence on the color strength (k/s value) of the dyed material. The k/s value increases with the increase of dyeing period up to 120 minutes. The maximum color strength (0.76) was noted for the fabric. The shorter dyeing time produces lighter samples and the longer dyeing time produced colorful samples.
 Journal of Engineering Science 11(1), 2020, 37-42

Measuring Camellia Petal Color Using a Portable Color Sensor

The color of petals of flowering plants is often determined by comparing one or more of the petals to various Royal Horticultural Society (RHS) Colour Chart cards until a color match is found. However, these cards are susceptible to fading with age and can also provide inaccurate results if lighting is not optimal. The cards also rely on the human eye to determine a match, which introduces the possibility of human error. The objectives of this study were to determine camellia (Camellia japonica L.) petal color using the RHS Colour Chart, to determine camellia petal color with the NixTM Pro color sensor (Nix Sensor Ltd., Hamilton, Ontario, Canada), and to compare these measurements using different color measuring approaches. Color measurements of camellia flower petals using the NixTM Pro color sensor were compared to published CIELAB values from the Royal Horticultural Society (RHS) Colour Chart. Forty-five petal color samples were collected from fifteen different camellia shrubs. The RHS Colour Chart was used for each of the petals, and the RHS identifications were recorded. Measurements using the NixTM Pro color sensor were compared to RHS-provided CIELAB values that corresponded with the recorded identification for each petal to determine accuracy. The NixTM Pro color sensor’s measurements were also compared to a mean of the values, multiple measurements on the same petal location, and multiple measurements on different petal locations to determine precision and variation. The Nix™ Pro color sensor’s readings were precise in petal color determination and provided more nuanced differences between petals of the same plant and plants of the same variety in each of the color categories. The RHS Colour Chart provided an accurate depiction of most petals, but it was difficult to use with petals that had wide color variation over the entire petal. The Nix™ Pro color sensor’s measurements appeared to have more variation in the b* color space. However, overall, the Nix™ Pro color sensor L*, a*, and b* values were highly correlated with the provided RHS values (p < 0.01), showing that the sensor can be used as an accurate and precise substitute for the RHS Colour Chart. The Nix™ Pro color sensor can be a useful, cost-effective tool to measure the petal color of camellia and other flowering plants and rectifies many of the problems associated with the RHS Colour Chart.

Synthesis and optical properties of Mn-doped Ba3Al2O6 intense blue oxides

Abstract The solid solution of Ba3Al2-xMnxO6+y (0 ≤ x ≤ 0.2) is successfully synthesized through solid state reaction. The colors of compounds are tuned from sky blue (x ≤ 0.1) to ocean blue (x = 0.2) with the increase of Mn content. The X-ray diffraction data shows that the major phase of all the as-synthesized samples is cubic Ba3Al2O6 structure with the space group of P213. The oxidation state of Mn is confirmed to be +5 by X-ray photoelectron spectroscopy analysis. UV–Vis absorption spectroscopy demonstrates that the sample's color comes from the d-d transition of Mn5+ located in [AlO4].

RETRACTED ARTICLE: Lightweight deep dense Demosaicking and Denoising using convolutional neural networks

A single sensor camera uses Color Filter Array (CFA) to capture single-color information at each pixel. Thus, to estimate the missing color samples and then to reconstruct an original image is known as CFA interpolation or demosaicking. Despite remarkable improvements made in the last decade, a fundamental issue remains to be addressed, i.e., how to assure the visual quality of an image in the presence of noise. Hence, the CFA images without denoising lead to the demosaicking artifacts that eventually reduce the image quality. Therefore, based on the aforementioned constraints, the paper presents a novel approach for demosaicking and denoising based on the convolutional neural network (CNN). The proposed technique is using CNN, which consists of four phases. In the first stage, the picture is sorted out. In stage-II, the demosaicking is performed utilizing the profound thick convolutional neural system, which gives us a demosaicked picture. In the stage-III, denoising performs and pass this picture to the last stage. At last, in the stage-IV, the picture goes to the last post-preparing stage delivering a better quality high-resolution image. To test the feasibility of the proposed scheme, Python language is utilized. The proposed conspire beats the few existing strategies regarding throughput delay, inactivity, precision.

COLORANTES NATURALES DEL VALLE DE ZONGO (BOLIVIA) Y SUS APLICACIONES TEXTILES

Three plants collected at the Zongo Valley were evaluated for textile dyeing applications. The species selected were extracted following acidic and basic procedures to obtain colored samples, that were submitted to direct and indirect (with mordents) dyeing techniques. In all experiments the need of a mordant was observed and the type of chemical mordant was identified. In each work, the strength of the fabric’s dye with the natural colorant was evaluated using a series of washing, rinsing, drying, ironing and exposure to sun light protocols. It was found that the acidic extract of Brachyotum microdon (flowers) needs Al 2 (SO 4 ) 3 to dye the fabric with a red cabernet tone, while the basic extract fixes the fabric with a brown color with FeCl 3 and green with FeSO 4 . The acid extract of the stems of Souroubea fragilis dyed the fabric with a light orange color when Al 2 (SO 4 ) 3 was used as a mordent, while the basic extract provided brown tones thanks to CuSO 4 or FeSO 4 . Finally, the acidic extract of Fuchsia boliviana (flowers and fruits) gave a pale rose and a green tinting with Al 2 (SO 4 ) 3 and FeCl 3 , respectively. The basic extract of this plant provided a green dyeing with CuSO 4 and orange shading with FeCl 3 . Different types of fabrics were evaluated, and the best dyeing results were observed with cotton. All the extracts studied presented antioxidant and photoprotector activities. The acidic extract of Brachyotum microdon (flowers) showed 82.5% of inhibition at 10µg/ml against DPPH and it absorbed the harmful UV B radiation. The acidic extract of Fuchsia boliviana (flowers and fruits) gave an 86.7% of inhibition at 10µg/ml against DPPH and it also absorbed the damaging UV B radiation. Finally, the acidic extract of Souroubea fragilis (stems) presented 92.1% of inhibition at 100µg/ml against DPPH and it absorbed both UV-B and UV-A radiations.

Vaccine Hesitancy and Attributions for Autism among Racially and Ethnically Diverse Groups of Parents of Children with Autism Spectrum Disorder: A Pilot Study.

Little is known about how racial/ethnic differences may influence attributions for autism spectrum disorder (ASD) and subsequent vaccine hesitancy, the latter of which refers to a continuum of concerns about vaccine safety that may lead to vaccine delays and/or refusals. Two hundred and twenty-five parents of children with ASD who were enrolled in the SPARK cohort (Simons Foundation Powering Autism Research for Knowledge) completed the Parent Attitudes about Childhood Vaccines survey and the Revised Illness Perception Questionnaire. 28.9% of respondents (n = 65) were vaccine hesitant (PACV score ≥ 50). Significant differences were observed between proportions of vaccine-hesitant parents (VHP) in the White sample and combined samples of color (Asian, Black, Latinx, Multiracial, and Other): 22.8% of the White sample (n = 39) versus 48.1% of the samples of color (n = 26). White, non-hesitant parents more often agreed with the child's brain structure as a cause of their child's ASD, while White, VHP more often agreed with the deterioration of the child's immunity as a cause. All VHP (regardless of race) agreed more often with diet, their own decisions, and vaccines as causes. VHP of color more often agreed with accident or injury, environmental pollution, their own general stress, and their own emotional state as causes. Future work should examine this phenomenon in larger, diverse samples to further understand differences across specific racial/ethnic groups. LAY SUMMARY: Some parents of children with autism spectrum disorder (ASD) are vaccine hesitant, meaning they have concerns about vaccine safety and may delay/refuse vaccines. We examined possible racial/ethnic differences related to how common vaccine hesitancy is and which causes of ASD were typically endorsed among a sample of caregivers in the SPARK cohort (Simons Foundation Powering Autism Research for Knowledge). Higher proportions of parents of color were vaccine hesitant, and all vaccine-hesitant parents agreed that "toxins in vaccines" were a cause of their child's ASD. Autism Res 2020, 13: 1790-1796. © 2020 International Society for Autism Research and Wiley Periodicals LLC.

Wool Fabrics Colored with Fluorescent Pigment Emulsion: Their Color Performance and Fluorescent Properties

ABSTRACT The fluorescent hue is brilliant and attractive, and is usually used in outdoor, traffic, and teenage clothes industry, as well as in marker and fields of warning signs. But the fluorescence coloration of natural fibers with fluorescent dyes is rare because of the inherent polymeric and optical property of natural fibers, and the dyes state on fiber. The wool fabrics can be colored with pigments emulsion or water dispersions by exhaustion process. In this paper, the wool fabrics were colored with fluorescent pigment emulsions by padding, and their dyeing properties were investigated by color measurement, spectrofluorometer, SEM, TG, and fastness testing. The color data, dominant wavelength (or complementary wavelength), and excitation purity of colored samples were measured and illustrated with chromaticity diagram. The fluorescence spectrum of colored samples was tested as well. The results showed, with the raise of amount of pigments emulsion, the K/S value, reflectivity, durability, and shrinkage of colored samples increased, whereas the softness decreased. There were FRET (fluorescence resonance energy transfer) phenomena in the colored samples. The fluorescent pigments emulsion deposited on the fabrics as resins between the wool fibers. The migration and rubbing fastnesses of all samples were good and were at grade 4 or above, but the light fastnesses were not good, and only at grade 3 or grade 3–4.

Strip-pair comparison method for building threshold color-difference model: theoretical model validation.

This paper presents a method for developing color-difference models near a threshold, based on the serial exploration method described by Torgerson [Theory and Methods of Scaling; Wiley & Sons (1958); Chap. 7], involving the construction of color-control strips of patches arranged in arrays of 2 × n, where n is the number of pairs in the strip. The patches in the lower row should be calorimetrically identical, while the color of the patches in the upper row should vary progressively in constant steps of CIELAB color difference along selected color space vector directions. Prospective observers are instructed to indicate the patch pair number for which they begin to perceive a slight color difference between corresponding patches. The frequency data obtained from the observers was used to build a threshold color-difference model. The intention was to validate the method with theoretical data to determine the effect of the precision with which the strips are constructed, on the accuracy of the estimated parameters. Theoretical frequency data was generated using the CIE94 color difference formula, whose associated color discrimination ellipsoid parameters are very easy to determine, associated with a hypothetical logistic psychometric curve for different color centers. The proposed method allows to determine color discrimination parameters with a precision nearby 4% and an accuracy of 3% with respect to the simulated theoretical parameters, for color samples generated with a standard deviation of ΔEab∗=0.2 of the superimposed error around the ideal color difference of pairs of patches.

Effects of Color Quantization on JPEG Compression

This paper analyzes the effects of color quantization on standard JPEG compression. Optimized color palettes were used to quantize natural images, using dithering and chroma subsampling as optional. The resulting variations on file size and quantitative quality measures were analyzed. Preliminary results, using a small image database, show that file size suffered an average 20% increase and a concomitant loss in quality was perceived ([Formula: see text]6dB PSNR, [Formula: see text]0.16 SSIM and [Formula: see text]9.6 Butteraugli). Color quantization present itself as an ineffective tool on JPEG compression but if necessarily imposed, on high quality compressed images, it might lead to a negligible increase in data size and quality loss. In addition dithering seems to always decrease JPEG compression ratio.