Color Research and Application最新文献

Our previous work revealed that the vision-based color representation of congenitally color-deficient observers (CDOs) was mostly C-shaped bending at yellow and blue that differed from circular shape of the observers with no color vision deficiencies called CNOs in the study. In this study, the color-name-based internal color representation was investigated for the same observers and its relation to the vision-based color representation was examined. First, psychological difference of all combinations of 10 color names corresponding to the Munsell basic hues was rated using a 5-point scale. The distances of all pairs of CNOs and the CDOs agreed well with each other, in contrast to the distinctive differences in the vision-based color representation. Second, color-naming was conducted to the 10 color chips for each of high and medium chroma to link the vision-based and color-name-based representations through the test stimuli. For the high chroma chips, color naming property of the CDOs was similar to that of the CNOs. In contrast, CDOs showed distinctively larger intra- and inter-observer variabilities than CNOs for the medium chroma chips. The difference between two color chips was estimated using the results of the color naming and extended color-name difference ratings which is called “color-naming difference.” No systematic relationship was observed among the color-chip difference, color-name difference, and color naming difference in individual comparisons. It indicated that the color-naming difference is greater for the pairs including YR/Y/GY versus G/B, and vice versa for the pairs consisting of BG, B, PB, P, and RP. These suggest the followings; first, CDOs seem to utilize lightness difference strategically in the visual assessment, second, psychological differences among “blue,” “green,” “purple,” or “gray” are distinct for CDOs although the color chips given those names in our experiment appear close.

A color rendition chart, the preferred memory color (PMC) chart, has been produced. It comprises 30 colored patches, divided into three groups: preferred memory colors, reference color-gamut colors, and a gray scale. The main purpose of the new chart is to enable users to produce satisfactory preferred color reproduction using digital cameras, displays, and printing systems. The methods used to develop the various colors, and the color specification of each color are presented. Finally, several potential applications of the chart for the characterization of imaging devices, for the evaluation of image color quality, and for the calculation of color rendering indices for lighting are suggested.

Plastics are commonly produced and sold in pellet form due to their superior handling characteristics. However, due to their small size, it is often impractical, if not unfeasible, to determine the transmittance of a single pellet instrumentally. Moreover, such measurements may be highly variable. Therefore, translucent films of certain thickness, known as plaques, are commonly molded to enable instrumental determination of their transmittance. These plaques, however, are not needed beyond the quality control process while they add a costly step to the production process. In this study, we test a method, based on the layer theory, that enables the estimation of the transmittance spectra of nearly transparent plastic plaques from the reflectance measurements of their pellet counterparts. The comparison of the estimated transmittance spectra of pellets versus measured transmittance of plaques shows the RMSE ranging from 0.37%–1.80%, with a color difference, CIEDE2000(1:1:1), of 0.07–0.48, thus validating the applicability of the method.

The papermaking, packaging, and printing industry are actively seeking sustainable material alternatives to address growing concerns about environmental consciousness and finite resources. Synthetic latex, a frequently utilized binder in paper coating formulations, present difficulties due to their dependence on fossil fuel resources and their reduced recyclability in comparison to eco-friendly sustainable products. In this study, synthetic latex was replaced with a starch-based nanoparticle (starch NP) binder at a 1:1 ratio in a coating formulation. Printing trials to assess colorimetric characteristics was made using electrophotography (EP) printing, given the current upward trajectory and expansion of EP technology into the label, packaging, and folding carton sectors. The in-depth investigations reveal that incorporating starch NP binder result in improved optical, color, and dot characteristics. Moreover, it maintains consistent and comparable coefficients of friction. Partial replacement of synthetic latex with the starch NP binder yields significant enhancements in surface roughness and text quality. Importantly, the starch NP binder not only improves the dielectric relaxation properties of the paper and enhances toner transfer but also accelerates the distribution of the electrical field compared to synthetic latex, optimizing toner transfer and thereby enhancing color gamut volume. The study demonstrates that employing the starch NP binder leads to substantial improvements in colorimetric performance without any drawbacks in EP printing, making it highly advantageous to replace 50% of the synthetic binder.

The transmission of color experience has become a central concern in the development of devices for blind and visually impaired individuals. Several techniques have been implemented, taking into consideration other sensory modalities, in an attempt to find the most suitable solution to intersemiotically translate this visual information. The primary objective of this paper is to investigate various approaches to convey chromatic information for individuals with low vision or blindness and emphasize the importance of multi-modal integration and cross-modal interaction among different senses. This research brings together a wide variety of strategies utilized to translate color codes, such as patterns, temperatures, scents, music, and vibrations, with the aim of uncovering the advantages and disadvantages of each technique. A review of the existing literature suggests that interaction between multiple sensory channels is more effective in compensating for lack of vision. As a particularly relevant case study, attention will be paid to the enjoyment of art by people with visual impairments.

This study was part of a doctoral research project which looked into the current issues with color education, documented by several authors in recent years. It presents a comprehensive analysis of 103 color courses taught within design programs of higher education institutions from different countries over the last 12 years, 2010–2022. The analysis aimed to define the state-of-the-art of including color training within higher education design programs, identify the main didactic strategies implemented, and recognize the main critical aspects to face when proposing an innovative framework for color training. Among the formal aspects analyzed are the course level, the course duration, the student entry profile, the specific disciplinary area, the course location, the type of institution, and the language of the course. The didactic strategy elements analyzed were the learning outcomes, the contents proposed by the course, the teaching strategies implemented, and the suggested bibliography. Finally, a description of the main findings of the analysis is provided to assess how color is being taught within the design area.

In order to enhance the accuracy and efficiency of color difference detection for dyed fabrics, this article introduces a novel superpixel-based color difference detection algorithm, which exhibits three significant improvements over the previous algorithm. First, it proposes a more rational color feature extraction method to extract more detailed color features from fabric images, which uses superpixels as basic units for both color feature extraction and color difference detection. Second, the algorithm employs the CIEDE2000 color difference formula to calculate color difference values. This eliminates the need for obtaining standard fabric images as references in advance, making the process more convenient and practical. Finally, an area-based color difference calculation method is proposed based on the human visual mechanism, ensuring that the evaluation results are more consistent with human eye observations. Experimental results demonstrate that the proposed algorithm provides more accurate and visually consistent color difference assessments compared to the previous algorithm.

Automatic analysis of images is increasingly being used to generate color insights and this has led to various methods for generating palettes. Several studies have recently been published that explore methods to predict the visual similarity between pairs of palettes and these methods are often used to evaluate different generative methods. This work is concerned with being able to predict visual similarity between color palettes. Three data sets (two of which were previously published) are used to evaluate two methods for predicting visual similarity between palettes. A novel palette-difference metric (based on the Hungarian algorithm) is compared to the previously published minimum color difference model (MICD) and was found to agree better with the visual data for two of the three data sets. Agreement between models and visual data was also better for CIEDE2000 (1, 2) than for CIELAB metrics.

Measuring color matching differences between observers is an important means of investigating individual differences in human color vision. In this article, we introduce a new LED-based visual trichromator with which we have estimated color matching functions and cone spectral sensitivities in a group of five normal observers. The trichromator has side-by-side semi-circular matching fields that are illuminated by two spectrally tunable LED light sources, each comprised of 18 LEDs with center wavelengths ranging from 400 to 700 nm. We used Maxwell's method to derive a set color match. A fixed triplet of red-green-blue (RGB) primaries produced the white standard field of 120 cd/m² in one field. The other field, the mixture field, was illuminated by one of 11 different triplets of lights with various center wavelengths. Observers adjusted the intensities of the triplets in the mixture field to match the white standard field. All matches were made for field diameters of 2° and 10° of visual angle to allow comparisons with colorimetric standards and were repeated five times. Calibrations and tests showed that the trichromator and the measurements were stable and repeatable. Grassmann's laws predict that at the 11 color matches the excitations in the three cone types should be the same. Consequently, we can use those matches and a model of how cone spectral sensitivities vary between individuals to estimate the three underlying corneal cone spectral sensitivities for each observer (and thus how they vary from the standard (or mean) observer). We find good agreement with the CIE 2006 standards, but our observers show small but consistent differences.