Color Tolerance Research Articles

Evaluation of wash colour strength of a printed garment with flexible filaments on 3D printers

The research aims to evaluate the solidity of the washing colour of a garment printed with flexible filaments on 3D printers. Three groups of factors have been selected: Anet A8 and M3D Crane Quad printer, temperature (49° and 71°C) and flexible filaments TPE (thermoplastic elastomer) and TPU (polyurethane thermoplastic), framed in the factorial design, type applied of 10 units per combination of factors in a total of 80 sampling units, using Girowah equipment according to the technical standard AATCC TM61-2020. The results show that the printer factors Anet A8 and M3D Crane Quad with the CIELab and CMC (2:1) discolouration system exceed 50% in both the tolerances of the value 1. About the temperature factor (49° and 71°C), which exhibits a discolouration of 1.06 in CIE94 and 1.36 in CMC, it is determined that the combination with better resistance to discolouration of solidity at washing (CIE94 - 49°C) compared to CMC (2:1) better establishes the visual and technical concordance of the solidity of colour. As regards flexible filament types: TPE and TPU, the results show us that the colour tolerance assessments (CIELab CIE94) and (CMC (2,1)) prove that the TPE filament has greater resistance to the discoloration of the 3D-printed garment at different temperatures. In conclusion, the solidity of colour washing in a printed garment with flexible filaments in a 3D printer causes discolouration by the minimum, be it the factors of printer type, filament, and temperature. There is a need for analysis with other values and it remains open to other research.

Yellow light emitting Cs2Zr0.99Te0.01Cl6 with high efficiency emission via modified co-precipitation method synthesis for the light-emitting device

While lead-free perovskite has attracted widespread interest in the optical field by overcoming their toxicity and stability disadvantages compared to conventional lead-based perovskite, the low photoluminescence quantum yield (PLQY) of lead-free perovskite has greatly limited their commercialization path. In this research, a modified co-precipitation method was used to prepare Cs2ZrCl6, which was achieved by the addition of TeCl4 to shift the emission wavelength from 436 to 556 nm with bright yellow emission, the optimal PLQY of 98.2% was achieved by the addition of Te4+ in the amount of 1 % and the optimization of the reaction concentration. First-principles calculations and spectral analysis of Cs2Zr1-xTexCl6 show that the broadband yellow light emission comes from self-trapped excitons (STEs) in Cs2Zr1-xTexCl6. In addition, the luminous intensity of the prepared Cs2Zr1-xTexCl6 was 57.3, 63.3 and 90.1% of the initial intensity after exposure to air for 30 d, cyclic intermittent heating to 200°C and ultraviolet (UV) irradiation for 7 d, respectively. Finally, Cs2Zr1-xTexCl6 and Cs2ZrCl6:10% Bi were used as phosphors and encapsulated with a UV chip to make three different colors of light-emitting diodes (LED), where the white LED (WLED) had CIE coordinates of (0.3061 0.3244), color temperatures, color rendering indices as well as color tolerances of 6921 K, 84 and 6.52 respectively. This research provides a new approach to improve the performance of lead-free perovskite.

Study of Lighting Design for Interior Spaces

Due to the continuous progress of lighting fixture technology, people's requirements for commercial space design are also rising, and the comfortable, convenient, artistic, and technological combination of space is more and more emphasized by designers. The author has collected a large amount of visual subjective evaluation data through actual investigation and experimentation and conducted extensive and in-depth research on the light source's low radiation, luminous flux, luminous intensity, illuminance, luminance, color temperature, color deviation, color tolerance, beam angle, and maintenance coefficient. This paper takes the lighting quality parameters as the benchmark, analyzes the formal aesthetic relationship between commercial space and lighting design, and has a certain reference value for both lighting workers and academic research.

Visual color inspection with a hyperspectral camera: inline application for automotive parts production

The development of cars is becoming increasingly focused on colour, which is a major challenge for both suppliers and manufacturers. Manufacturers must establish strict colour tolerances for each coloured component and specify both colour and appearance. On the other hand, suppliers must maintain colour accuracy in part production, regardless of the type of material used, to ensure acceptance of colour by automotive manufacturers. In the colour industry, colour difference formulas are used to make unbiased judgments about whether manufactured goods should be approved or disapproved. These objective judgments are based on instrumental colour measurements that must accurately predict subjective colour variations. Hyperspectral imaging (HSI) has proven to provide helpful data for a variety of applications in numerous industries, including colour science. To measure and analyse colour differences between automotive parts, we proposed to use conventional colour science algorithms in conjunction with the Specim FX10 hyperspectral camera, which has a flexible infrastructure that can receive data from a Generic Interface for Cameras (GenICam) compatible with the Gigabyte Ethernet interface. The results showed that the use of hyperspectral imaging in production offers great potential for providing real-time colour information so that colour shifts can be detected early and costly errors in the production line can be avoided.

Evaluating the color stability of two esthetic ceramic materials after different surface treatments and accelerated aging procedures

Aim: Observing and evaluating the long/short-term discoloration tendency of the esthetic prosthetic materials of lithium disilicate-based glass-ceramics (IPS e.max CAD LT) and leucite-based feldspathic glass-ceramics (VITA Mark II) materials, which are esthetically very close to each other at first glance.
 Methodology: 80 samples of A2 colored lithium disilicate and feldspathic blocks samples were overglazed and polished separately to evaluate the surface treatment procedures according to CIELAB color coordinates. For accelerated aging purposes, half of the examples were treated to red wine, and the other half were treated to coffee. Color changes were calculated using the ΔE formula. The results were put into record as ΔE-1, ΔE-2, and ΔE-3. Records of the results were evaluated using IBM SPSS Statistics Standard Concurrent User V 25 statistics package program. Data distribution regarding numerical variety and changes were evaluated using the Shapiro Wilk normality test and Q-Q graphics. 
 Results: The data was evaluated using O'Brien clinical color tolerance scales. None of the samples has shown a perfect (ΔE=0-0.5) color match after 4 weeks of accelerated aging. Every group has shown results of significant statistical changes at various rates and percentages and divided into 4 subgroups as excellent, good, clinically acceptable and incompatible categories.
 Conclusion: Since aging procedures affect ceramic systems' ΔE values in a variety of ways, the aging protocol utilizing in vitro aging techniques for color changing should be evaluated alongside ceramic type and surface finishing procedures.

Color difference of yarn-dyed fabrics woven from warp and weft yarns in different color depths

PurposeThis paper aims to determine the most practically applicable color-difference formula for yarn-dyed fabrics woven from warp and weft yarns in different color depths and to establish color-difference tolerance for perceptibility by evaluating yarn-dyed fabrics visually and instrumentally.Design/methodology/approachA total of 108 sample pairs were evaluated by a panel of 13 observers with perceptibility method under three typical light sources (A, D65 and cool white fluorescent). The data sets were statistically analyzed by the homogeneity of variance test (F-test), analysis of variance, standardized residual sum of squares and performance factor/3.FindingsLight sources had a slight influence on the visual assessments of yarn-dyed fabrics. Among the eight color-difference formulae for measurements of yarn-dyed fabrics, CIEDE2000(2:1:1) outperformed all other tested formulae, and the color tolerance for the perceptibility of CIEDE2000(2:1:1) was 0.62. When the homochromy index (K) of warp and weft yarns of yarn-dyed fabric was lower than 1.25, the color difference based on ΔE*00(2:1:1) between the two samples was acceptable in terms of the color tolerance for perceptibility (i.e. 0.62).Practical implicationsThe warp and weft yarns in different color depths could be woven in fabric with a relatively uniform color appearance.Originality/valueThis study could contribute to cost savings by reusing disqualified dyed yarns during the weaving manufacturing process.

Acceptability-based Brand Color Tolerance, A Case Study

The Pantone® Formula Guide (or Guide), printed using specially-formulated inks on specified substrates, has been used widely by brands to specify brand color aims. While the Guide is silent on brand color tolerance, there are two competing criteria that influence the brand color tolerance, i.e., perceptibility and acceptability. Perceptibility-based color tolerance focuses on “Can I see the difference?” and the permissive difference is in the just-noticeable difference (JND) region. Acceptability-based color tolerance, focusing on “Can I accept the outcome?”, requires fit-for-use cases to identify what the just-acceptable difference (JAD) is. Instead of conducting psychometric tests, this research uses the 2019 Pantone® Formula (Coated) Guide, consisting of 2140 CIELAB colors, and data analyses of the “neighboring color difference” to investigate what is the acceptability-based color tolerance. The result shows that the acceptability-based color tolerance (3 ΔE00) has more margin than the perceptibility-based color tolerance (2 ΔE00).

Using the Knowledge of Post-transcriptional Regulations to Guide Gene Selections for Molecular Breeding in Soybean.

The omics approaches allow the scientific community to successfully identify genomic regions associated with traits of interest for marker-assisted breeding. Agronomic traits such as seed color, yield, growth habit, and stress tolerance have been the targets for soybean molecular breeding. Genes governing these traits often undergo post-transcriptional modifications, which should be taken into consideration when choosing elite genes for molecular breeding. Post-transcriptional regulations of genes include transcript regulations, protein modifications, and even the regulation of the translational machinery. Transcript regulations involve elements such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) for the maintenance of transcript stability or regulation of translation efficiency. Protein modifications involve molecular modifications of target proteins and the alterations of their interacting partners. Regulations of the translational machinery include those on translation factors and the ribosomal protein complex. Post-transcriptional regulations usually involve a set of genes instead of a single gene. Such a property may facilitate molecular breeding. In this review, we will discuss the post-transcriptional modifications of genes related to favorable agronomic traits such as stress tolerance, growth, and nutrient uptake, using examples from soybean as well as other crops. The examples from other crops may guide the selection of genes for marker-assisted breeding in soybean.

A method proposal for evaluating color tolerance in viewing multiple white points focusing on the vehicle instrument panels

Although chromatic adaptation eases us to adopt our vision to nuanced whites, viewing more than two substantially different white balances costs perceptual workload and appeals to poor quality control. This study proposed a method for evaluating the color tolerance of light modules using a uniformity analyzer focusing on the instrument panels in passenger cars, two premium line-up vehicles from Hyundai and Mercedes Benz. Using a luminance uniformity analyzer, we captured three main lighting regions in their instrument panels: clusters, steering wheel, and center console. Based on u’ and v’ values, we identified and compared the chromaticity coordinates of the white lighting components. The measurement-based judgment supports the manufacturer in achieving the quality objectively and consistently.

Establishment of a color tolerance for yarn‐dyed fabrics from different color‐depth yarns

AbstractYarn‐dyed fabric is often woven from warp and weft yarns in the same color depth to ensure a uniform color appearance. The difference in color depth between warp and weft tends to result in the uneven color of the yarn‐dyed fabric. This article aims to establish a color tolerance for yarn‐dyed fabric that can be woven with a qualified color appearance but from the warp and weft yarns in different color depths. A total of 27 yarn‐dyed fabric samples in three color series (red, yellow, and blue) were evaluated by using the yarn‐dyed fabric from warp and weft yarns in the same color depth of 2% (on weight of fabric, owf) as the standard. Visual assessment and instrumental measurement of color were carried out to establish the color tolerance ellipse that was defined as CMC (Color Measurement Committee) color differences (2:1) of no more than 1.00. It was found that the color strengths (K/S) and color differences (ΔECMC(2:1)) of these fabric samples for each color series had linear relationships with the color depths of warp and weft yarns. The color tolerance ellipses indicated that, even though the warp and weft yarns had an apparent color difference, they could be woven in fabrics with relatively uniform color appearance and meet the requirements for yarn‐dyed fabric. This work provided valuable insight into the production of qualified yarn‐dyed fabrics from unqualified dyed yarns.

Expanding the color gamut of inkjet textile printing during color matching

AbstractOne of the most important subjects of digital printing is evaluation of color gamut mapping. A printer can only reproduce colors that are in its color gamut. Maybe, a color tolerance between reference sample and printed sample is in agreement between manufacturer and customer. The goal of this work is to estimate the expansion of the color gamut of an inkjet textile printer by consideration of the acceptable (predetermined) color difference during color matching. For analyzing the color gamut, a standard color chart IT8.7/4‐2005 CMYK target was printed by nine different mixtures of CMYK, and then the reflectance spectra and colorimetric parameters of the printed samples were measured. The inks used were disperse water‐based inks that were printed on the polyester fabric. The maximum acceptable color difference in this study was equal to 2 CIELAB units for all colors. In order to estimate the color gamut with the maximum acceptable color difference, for all boundary points of gamut, expanded points were obtained by Euclidean distance less than = 2. The results show that when the acceptable color difference is considered in color gamut measuring, the area and volume of the color gamut are increased and so, the reproducibility of printer is increased. The maximum and minimum expansions of color gamut volumes were obtained by the mixtures with minimum and maximum color gamuts, respectively. The volume expansion of the mixture with the minimum color gamut volume was 34.20%, while the volume expansion of the mixture with the maximum color gamut volume was 28.06%.

Approximation of CIEDE2000 color closeness function using Neuro-Fuzzy networks

The development of efficient algorithms that perform qualitative operations in the processing and segmentation of graphical images requires good knowledge on both technical and biological aspects of the vision. Due to the subjective nature of the human vision, the evaluation of color identity and closeness, that has been widely used in a variety of image processing problems, is still subjected to research and improvement. This paper analyzes the problem of color tolerance, overviewing past and existing solutions, and suggests a simple Adaptive Neuro-Fuzzy Inference System (ANFIS)-based model as an alternative to the formula-based closeness evaluation. The aim of this research was to develop an alternative to the unified closeness formula, which could be built on expert knowledge or be adapted to fit a particular target. Methods of sample selection, training approaches, and configuration of the ANFIS network were used and a comparative analysis between the ANFIS models and the neural networks was provided. Additionally, the efficiency of regular back-propagation, hybrid, and stochastic learning methods were evaluated along with a critical analysis on the widely used hybrid training method. Experiments were designed and ran on a Java-based platform-independent system, developed as part of our research, to provide flexibility in the modeling and integration for the ANFIS based tasks.

Determining Tolerance Values of Instrumentally Measured Color Differences to Evaluate Black Filament Yarns

There are many factors affecting the tolerance values of instrumentally measured color differences, including variety of industries, type of products to be matched with the original samples, the need of customers, etc. Regarding the insufficiency of various color difference formulae to deal with the acceptability of color matching of reproduced samples with the target, some researchers tried to present an instrumental color tolerance limit in accordance with the results of visual assessment experiments. Considering the specific colorimetric attributes of achromatic samples (with low lightness and chroma values), it was tried to set an instrumental tolerance limit based on the measured and visually perceived color differences between 20 filament black yarns and the reference one. The results showed that determining the color tolerance value based on various color difference formulae, i.e. ΔEa*b*, CIE94, CIE2000 and CMC (2:1), results in different instrumental wrong decisions, while the ΔE*ab color difference equation with the color tolerance value of 0.5 for filament black yarns showed the minimum number of wrong decisions.

Fast Method of Registration for 3D RGB Point Cloud with Improved Four Initial Point Pairs Algorithm.

Three-dimensional (3D) point cloud registration is an important step in three-dimensional (3D) model reconstruction or 3D mapping. Currently, there are many methods for point cloud registration, but these methods are not able to simultaneously solve the problem of both efficiency and precision. We propose a fast method of global registration, which is based on RGB (Red, Green, Blue) value by using the four initial point pairs (FIPP) algorithm. First, the number of different RGB values of points in a dataset are counted and the colors in the target dataset having too few points are discarded by using a color filter. A candidate point set in the source dataset are then generated by comparing the similarity of colors between two datasets with color tolerance, and four point pairs are searched from the two datasets by using an improved FIPP algorithm. Finally, a rigid transformation matrix of global registration is calculated with total least square (TLS) and local registration with the iterative closest point (ICP) algorithm. The proposed method (RGB-FIPP) has been validated with two types of data, and the results show that it can effectively improve the speed of 3D point cloud registration while maintaining high accuracy. The method is suitable for points with RGB values.

Developing a peripheral color tolerance model for gaze-contingent rendering

Developing a peripheral color tolerance model for gaze-contingent rendering

Ampelographic collection of NSС «V.Ye. Tairov IVW», current trends in studies and prospects of usage

The aim of our research was to analyze the composition of an ampelographic collection of the V. Ye. Tairov Institute of Viticulture and Winemaking by geographical origin of varieties, application, ripening period, berry color, flavor profile, seed development, winter hardiness and frost tolerance, and resistance to major fungal diseases. To enrich the database of varieties – sources and donors of valuable traits via analysis of data on expression of adaptability and performance characteristics. Results and Discussion. At present, there are 736 varieties in the ampelographic collection of the V. Ye. Tairov Institute of Viticulture and Winemaking. The largest portion contains Ukrainian, Russian and Moldavian varieties. More than half (59 %) are table varieties; one third (31%) are wine ones; and 10 % are universal varieties and varieties that are still being studied. As to the ripening period, a group of early-ripening, mainly table varieties (23 %), stands out. The most numerous portions of the collection are mid- and late-ripening varieties (17 % each). The percentages of early-middle and mid-late varieties are similar (11 and 12 %, respectively). Among the berry colors, white and its variations (yellow, yellow-green, amber, etc.) account for 44 %; black – for 23 %; and pink – for 6 % of the collection accessions. There are varieties with red-violet, white-pink, yellow-pink, pale red or bright red berries. Significant diversity was also found in flavor characteristics of the collection accessions. Even in the largest group with so-called “simple taste” (86 % of the collection accessions), varieties with bright prune, solanum, flower, honey and other aromas were found. Varieties with muscat flavor remain in high demand on the market. It was found in 12.5 % of varieties, which can be used in further breeding process. The collection contains 7 % of seedless varieties. Among the collection accessions with their diverse genetic and geographical origin, 82 % have low winter hardiness and frost tolerance and are damaged even at –20 – 21oC. They are mainly European varieties without genetically determined mechanisms of protection against low temperatures and overwintering conditions. 17.9 % of the collection accessions vary from relatively frost tolerant (−22 – 24oC) to frost tolerant (−26–28oC). More than half of the collection accessions (64.5 % ) are susceptible to fungal diseases, since they derive from non-resistant varieties. They are mainly intraspecific Vitis vinifera L. varieties. They are used in crosses as donors of product quality characteristics. A third of varieties showed relative resistance to diseases (6–7 points on a 9-point scale (Bankovska, 2007)). They are widely used in further crosses to obtain genotypes with genetically determined disease resistance. Conclusions. The observations and analysis of adaptive and productive characteristics of 735 collection varieties of the V. Ye. Tairov Institute of Viticulture and Winemaking have resulted in enrichment of the database both with introduced and with our own valuable varieties - donors.

Munsell Color Specification using ARCA (Automatic Recognition of Color for Archaeology)

Munsell Soil Charts are a very common tool used by archaeologists for the color specification task. Charts are usually employed directly on cultural heritage sites to identify color of soils and collected artifacts. However, charts are designed to be used specifying the color through subjective perception of users, by visual mean, in a time-consuming and error-prone procedure. It is likely that two users may estimate different Munsell notations for the same specimen, as colors are not perceived uniformly by different people. Hence, estimation process should be repeated several times and by more than a single expert user to be considered reliable. In this work, we employ our framework, Automatic Recognition of Color for Archaeology (ARCA), specifically designed to provide a method for objective, deterministic, fast, and automatic Munsell estimation. ARCA is a valuable asset for archaeologists as it provides the definition of a smooth pipeline for an affordable Munsell notation estimation: image acquisition of specimens with general purpose digital cameras in an uncontrolled environment, manual sampling of specimen images in the ARCA desktop application, automatic Munsell color specification, and report generation. We further assess our method with improved color tolerance validations and evaluations, introducing a comparison between Δ E 00 , Δ E 76 , Δ L *, Δ a *, and Δ b * differences. One of the main contributions of this article is the extension of our former dataset ARCA108. We gathered two additional sets of images obtaining a new dataset consisting of pictures of Munsell Soil Charts Editions 2000 and 2009 plus images from a real test case with 16 pottery shards. The new dataset counts 56,160 samples and 328 images, so it has been called ARCA328. Experimental results are reported to investigate which could be the best configuration to be used in the acquisition phase.

Hitting the Mark—A New Color Difference Metric for HDR and WCG Imagery

With the emerging demand for high dynamic range (HDR) and wide color gamut (WCG) technologies, display and projector manufacturers are racing to extend their color primaries in the cinema and in the home. With these brighter and wider colors, the question is: in calibration, how close is close enough? This answer is increasingly important for both the consumer and professional display/projector market as they balance design trade-offs. With HDR/WCG technology, an increasing issue is that many of the color difference metrics in common use today, such as $\Delta E_{00}$ , substantially deviate from human perception and become unreliable for measuring color differences. This causes under and over prediction of color differences and can lead to suboptimal design decisions and difficulties during calibration. There is a large amount of perceptual color difference data in the field today; however, the majority was collected using reflective surfaces and very little reaches the boundaries of modern display capabilities. To provide a better tool for facilitating design choices, this paper will present a ground truth visible color difference data set. These visual experiments were conducted between luminance levels of 0.1 and 1000 cd/m 2 on HDR laser cinema projectors with approximate BT.2100 color primaries. We present our findings, compare against current metrics, and propose specifying color tolerances using the $\Delta $ IC T C P metric for HDR and WCG imagery.

Study of color perceptibility of gonio‐apparent panels with curvature angle

AbstractColor tolerances of curved gonio‐apparent panels have been studied in this work. To achieve that, an experimental set‐up of the illumination and tilt variation of two identical coated panels was designed for simulation of curved panels with both concave and convex borders and with and without effect pigments (perceived as solid and gonio‐apparent colors, respectively). Finally, visual and instrumental measures were collected with both curvatures. The results show that the relationship of the instrumental color difference with the tilt angle can be modeled by a second‐order and the vertex did not depend on illumination, but on coating type. The critical angles (the angle marked when the color discrepancy between two identical samples is merely perceived) assessed by the observers showed that they were not equal according to border, nor according to coating type. The color tolerances at these angles were clearly higher than the conventional chromatic thresholds of industrial color comparisons.

Implementation Segmentation of Color Image with Detection of Color to Detect Object

Detection of objects in an image 2 dimensional is a process which is quite complex to do. Object detection required a computer vision approach to the desired part of the object can be recognizable computer accurately. The method in this research using waterfall method. This research will describe the application of color segmentation method with the color detection of a digital image to produce image segment object in the form of blob so that the computer can be detected. The object detection process will process the resulting color segment by the process of segmentation so that can know the number of detected objects, the area and the center of the object. This application can take pictures with laptop or notebook webcam. The result of color segmentation based on color detection is strongly influenced by color samples and color tolerance values to which the segmentation process is based. Lighting, location, texture, and contour of objects or background image will greatly affect the results of segmentation and object detection.