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Your search keyword '"CIELAB colour space"' showing total 4 results
Start Over Descriptor "CIELAB colour space" Topic color
4 results on '"CIELAB colour space"'

1. Colour Changes of Acetal Resins (CAD-CAM) In Vivo.

Author

Gómez-Polo, Cristina, Martín Casado, Ana María, Quispe, Norberto, Gallardo, Eva Rosel, and Montero, Javier

Subjects
ACETAL resins, INDEPENDENT variables, COMPLETE dentures, COLOR, REGRESSION analysis
Abstract

To quantify the discolouration of the temporary acetal resins in vivo, based on the weeks of follow-up and the salivary pH in the three thirds of the tooth. To find out if the final CIELAB coordinates can be predicted from the initial colour coordinates, the salivary pH, the situation (in thirds) and the weeks of follow-up. Colour coordinates (L, C, and h) were recorded by spectrophotometry in 13 participants fitted with hybrid provisional complete dentures made of acetal resin. Colour recordings were made on the day of placement and after several weeks of follow-up (6 to 31 weeks). Salivary pH was also measured as a predictor variable for colour change. The ANOVA statistical test and regression models have been used. The highest colour difference according to ∆Eab* was 27.46 units after 15 weeks of follow-up and the lowest was 7.34 units after 17 weeks of follow-up. Neither in the cervical nor in the middle third any regressor variable (initial L*, initial C*, initial h*, salivary pH and weeks of follow-up) was able to significantly predict any of the final colour coordinates (p > 0.05). The colour change of the temporary acetal resins used exceeds the threshold of clinical acceptability, and it is not acceptable to maintain satisfactory aesthetics. The weeks of follow-up and the salivary pH are not capable of satisfactorily predicting the final color coordinates of the acetal resins. [ABSTRACT FROM AUTHOR]

Published
2023
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2. Evaluation of Use of Digital Image Analysis on Colour Stability of Commercially Available Porcelain.

Author

Ghosh, Saumyadeep, Das, Samiran, Bhattacharyya, Jayanta, Ghosh, Soumitra, Paul, Rahul, Jana, Supriyo, Majumdar, Sayan, and Roy, Shubhabrata

Subjects
*COLOR space, *IMAGE analysis, *PORCELAIN, *COLOR, *TOOTHBRUSHES
Abstract

Introduction: Comparative evaluation in terms of colour stability of glazed and polished porcelains, has been discussed in literatures, but still controversies are present regarding superiority in terms of aesthetics, especially after toothbrushing. Aim: To evaluate the colour stability of three brands of porcelains in glazed and polished state after performing regular brushing and immersing into different staining solutions. Materials and Methods: An in-vitro study was conducted with a total of 30 specimens of glazed porcelain discs comprising of IPS E.max Computer-aided Design (CAD), Zenoster, and Jyodent were fabricated by CAD/Computer-aided Manufacturing (CAM) milling during April, 2018 to March, 2019. Samples were subjected to power tooth brushing and immersed into solutions of coffee, tea, and pan masala, respectively. For colour measurement, digital image analysis was performed using CIELAB colour space. After stipulated time period, glaze layer was removed, chairside polishing was done, and similar procedures were repeated. Results: In terms of colour stability of glazed and polished porcelains, Zenoster was found most colour stable in glazed and polished state (p=0.05). In terms of staining ability, coffee was found the most discolouring agent among 3 solutions at any time period on glazed samples (p>0.05), as well as on polished samples (p<0.05). Conclusion: Zenoster zirconia is the most colour stable in glazed and polished state and regular tooth brushing merely have any effect on glaze layer. Chance of staining is maximum in coffee than tea and pan masala for both glazed and polished porcelains. [ABSTRACT FROM AUTHOR]

Published
2024

3. Intra-specific pelage color variation in a South American small rodent species

Author

Rubén M. Barquez, José Sandoval, M. L. Sandoval Salinas, and Elisa M. Colombo

Subjects
Male, 0106 biological sciences, ESPECTORADIÓMETRO, Rodent, genetic structures, 01 natural sciences, purl.org/becyt/ford/1 [https], lcsh:Botany, lcsh:Zoology, lcsh:QL1-991, lcsh:Science, lcsh:QH301-705.5, Mammals, Sex Characteristics, ARGENTINA, TEMPORADA, biology, Arvicolinae, Akodon budini, Ecology, SEXO, lcsh:QK1-989, Homogeneous, South american, COLECCIONES, Principal component analysis, Female, Seasons, Analysis of variance, General Agricultural and Biological Sciences, CIENCIAS NATURALES Y EXACTAS, Coat, Otras Ciencias Biológicas, 010607 zoology, Zoology, Environment, 010603 evolutionary biology, Ciencias Biológicas, CIELab colour space, biology.animal, Animals, sex, COLOR, Hair Color, purl.org/becyt/ford/1.6 [https], ESPACIO DE COLOR CIELAB, biology.organism_classification, lcsh:Biology (General), spectroradiometer, Color data, lcsh:Q, season
Abstract

Intra-specific color variation is often underestimated by researchers, and among mammalian species, intra-specific differences in coloration are poorly documented for most species. The main goal of this study was to apply an objective color measurement methodology to the study of a specific problem: the detection, if any, of patterns of changes in the fur color of specimens of Akodon budini in relation to biological (i.e., sex) and environmental (i.e., season) variables. We hypothesize that male coat color will be more homogeneous than that of females and that the winter coat color will be darker than that of summer, the latter being orange. We measured the pelage color on five points over the dorsal surface of 26 A. budini museum specimens region using a spectroradiometer and a diffuse illumination cabin. We used Principal Component Analysis to describe the association between the color variables, sex and season, and each of the observations. We then used general linear models of Analysis of Variance to examine relationships between color data, season, and sex. The results clearly confirm the hypothesis related to seasonal coat color change but do not directly confirm the hypothesis related to changes in coat color in relation to sex, and we show the complexity of the studied pattern. In conclusion, undoubtedly, the studied variables should accordingly be taken into account when studying the coloration of specimens for characterization, identification and discrimination of different taxonomic units based on color. Variação de cor intra-específica é muitas vezes subestimada pelos pesquisadores, e entre espécies de mamíferos, as diferenças intra-específicas na coloração são pouco conhecidas para a maioria das espécies. O principal objetivo deste estudo foi aplicar uma metodologia objetiva de medição de cor para o estudo de um problema específico: a detecção de padrões de mudanças na cor da pele de espécimes de Akodon budini em relação a variáveis biológicas (i.e., sexo) e ambientais (i.e., temporada), se houver. Nossa hipótese é que a cor da pelagem do sexo masculino será mais homogênea do que a de fêmeas e que a cor da pelagem do inverno vai ser mais escura do que a de verão, sendo esta última mais laranja. Medimos a cor da pelagem em cinco pontos sobre a superfície dorsal de 26 espécimes de museu de A. budini usando um espectroradiômetro e uma cabine de iluminação difusa. Usamos Análise de Componentes Principais para descrever a associação entre as variáveis de cor, sexo e temporada, e cada uma das observações. Em seguida, usamos modelos lineares gerais da Análise de Variância para verificar as relações entre os dados de cor, temporada, e sexo. Os resultados confirmam claramente a hipótese relacionada à mudança sazonal de cor da pelagem, mas não confirmam diretamente a hipótese relacionada com alterações na cor da pelagem em relação ao sexo, e vamos mostrar a complexidade do modelo estudado. Em conclusão, sem dúvida, as variáveis estudadas devem consequentemente ser tidas em conta quando se estuda a coloração de amostras para caracterização, identificação e discriminação de diferentes unidades taxonômicas com base na cor. Fil: Sandoval Salinas, Maria Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Programa de Investigación de Biodiversidad Argentina; Argentina Fil: Barquez, Ruben Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Programa de Investigación de Biodiversidad Argentina; Argentina Fil: Colombo, Elisa Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Luminotecnia, Luz y Visión; Argentina Fil: Sandoval, Jose Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Investigación en Luz, Ambiente y Visión. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Instituto de Investigación en Luz, Ambiente y Visión; Argentina

Published
2017

4. Digital Image Sensor-Based Assessment of the Status of Oat (Avena sativa L.) Crops after Frost Damage

Author

Isidro Villegas-Romero, Antonia Macedo-Cruz, Gonzalo Pajares, and Matilde Santos

Subjects
food.ingredient, Avena, unsupervised classification, Color, fuzzy error matrix, digital image sensor, lcsh:Chemical technology, Biochemistry, Fuzzy logic, Article, Analytical Chemistry, Multispectral pattern recognition, agricultural images, automatic thresholding, CIELab colour space, oat frost damage, Digital image, food, Fuzzy Logic, Histogram, Image Processing, Computer-Assisted, Humans, Computer vision, lcsh:TP1-1185, Electrical and Electronic Engineering, Instrumentation, Mathematics, Electronic Data Processing, Models, Statistical, Spectral signature, business.industry, Temperature, Reproducibility of Results, Agriculture, Equipment Design, Thresholding, Atomic and Molecular Physics, and Optics, Inteligencia artificial, Cold Temperature, Frost, Artificial intelligence, business, Algorithms, Color Perception, Environmental Monitoring
Abstract

The aim of this paper is to classify the land covered with oat crops, and the quantification of frost damage on oats, while plants are still in the flowering stage. The images are taken by a digital colour camera CCD-based sensor. Unsupervised classification methods are applied because the plants present different spectral signatures, depending on two main factors: illumination and the affected state. The colour space used in this application is CIELab, based on the decomposition of the colour in three channels, because it is the closest to human colour perception. The histogram of each channel is successively split into regions by thresholding. The best threshold to be applied is automatically obtained as a combination of three thresholding strategies: (a) Otsu's method, (b) Isodata algorithm, and (c) Fuzzy thresholding. The fusion of these automatic thresholding techniques and the design of the classification strategy are some of the main findings of the paper, which allows an estimation of the damages and a prediction of the oat production.

Published
2011
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