• Applied Chemistry for Engineering
• /
• v.34 no.2
• /
• pp.131-136
• /
• 2023

We developed a method to measure the concentration of highly concentrated colored samples using color coordinates. We present a color analysis to estimate the concentration of highly concentrated binary solutions with an empirical function and apply it to estimate the kinetics of a catalytic irreversible reaction of resazurin to resorufin. The developed method enabled one to measure the concentration of solutions whose range of concentrations is nonlinear and beyond the limit of UV-vis spectroscopic measurement directly without dilution.

• Journal of Korea Multimedia Society
• /
• v.20 no.11
• /
• pp.1741-1749
• /
• 2017

In commercial digital-cameras, color-filter filters light according to wavelength range of color filter array (CFA) and the filtered intensities contain color information of light. Then, output data of CFA is transformed to final rendered image through demosaicing process. In image processing of digital-camera, the quality of the final rendered image is affected by optical cross talk of CFA, kind of CFA pattern etc. Basically, pattern of CFA plays important role in image quality of final image rendered by digital-camera. Therefore, an evaluation system capable of quantitatively evaluating CFA is needed. This paper proposes a novel evaluation system using existing and proposed image metrics for evaluating CFAs of digital-camera. Proposed CFA evaluation system consist of color difference in CIELAB and S-CIELAB, Structure SImilarity (SSIM), MTF50, moire starting point (MSP), and subjective preference (SP). MSP and SP are newly designed for the proposed evaluation system. Proposed evaluation system is expressed in polar coordinates to analyze the characteristics of CFA objectively and intuitively. Through simulations, we confirmed that proposed CFA evaluation system can objectively assess performance of developed CFAs.

• IEIE Transactions on Smart Processing and Computing
• /
• v.4 no.4
• /
• pp.272-280
• /
• 2015

This paper proposes color databases that can be used for various purposes for people with a color vision deficiency (CVD). The purpose of this paper is to group colors within the sRGB gamut into the CIE $L^*a^*b^*$ color space using the Brettel algorithm to simulate the representative colors of each group into colors visible to people with a CVD, and to establish a confusion line database by comparing colors that might cause confusion for people with different types of color vision deficiency. The validity of the established confusion lines were verified by using an Ishihara chart. The different colors that confuse those with a CVD in an Ishihara chart are located in the same confusion line database for both protanopia and deutanopia. Instead of the 3D RGB color space, we have grouped confusion colors to the CIE $L^*a^*b^*$ space coordinates in a more distinctive and intuitive manner, and can establish a database of colors that can be perceived by people with a CVD more accurately. Editor - Highlight - Do these changes reflect the intended meaning? If not, please rephrase as intended.

• Korean Journal of Materials Research
• /
• v.13 no.8
• /
• pp.509-513
• /
• 2003

In the present investigation, $La^{3＋}$ and $Ce^{V}$ ions were substituted for $Y^{3＋}$ in the $YBO_3$: Tb in various concentrations. It has been found that these phosphors form solid solutions within limited concentration ranges Excitation and emission spectra under 254 nm and 147 nm were investigated for these phosphors to evaluate influences of $La^{3＋}$ and $Ce^{3＋}$ ions on brightness and CIE color coordinates. It has been observed that brightness of $(Y, La)BO_3$: Tb under 254 nm and 147 nm when $La^{3＋}$ ions are added show an increase of 2.7 times and 1.25 times, respectively. On the other hand, emission intensities of peaks in $Y_{0.8-x}$ $BO_3$: $Tb_{0.2}$ , $Ce_{x}$ show continuos decrease as $Ce^{3＋}$ / content is increased from 0 to 0.4. CIE color coordinates of prepared phosphors show yellowish green which is needed to be improved to be used for display applications.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.6
• /
• pp.1469-1475
• /
• 2010

This paper presents a problem of existing encryption methods using pseudo-random numbers based on MLCA or complemented MLCA and proposes a method to resolve this problem. The existing encryption methods have a problem which the edge of original image appear on encrypted image because the image have color similarity of adjacent pixels. In this proposed method, we transform the value and spatial coordinates of all pixels by using pseudo-random numbers based on MLCA. This method can resolve the problem of existing methods and improve the level of encryption by encrypting pixel coordinates and pixel values of original image. The effectiveness of the proposed method is proved by conducting histogram and key space analysis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.141-143
• /
• 2010

This paper presents a problem of the existing encryption method using MLCA or complemented MLCA and propose a method to resolve this problem. With the existing encryption methods, the result of encryption is affected by the original image because of spatial redundancy of adjacent pixels. In this proposed method, we transform spatial coordinates of all pixels into encrypted coordinates. We also encrypt color values of the original image by operating XOR with pseudo-random numbers. This can solve the problem of existing methods and improve the levels of encryption by randomly encrypting pixel coordinates and pixel values of original image. The effectiveness of the proposed method is proved by conducting histogram, key space analysis.

• The Journal of Advanced Prosthodontics
• /
• v.15 no.5
• /
• pp.238-247
• /
• 2023

PURPOSE. The purpose of this study was to assess the effect of resin cement shade on the color of different novel ultratranslucent monolithic zirconia and lithium disilicate veneer materials. MATERIALS AND METHODS. For a total of 40 specimens, flat cylindrical discs with a 9-mm diameter and 0.5-mm thickness were created using CAD/CAM technology. The specimens were divided into five groups according to their material (n = 8) (e.max, Prettau, Aidite, Shofu and Dima) using A1 shade. Resin discs with the same diameter and shade as the specimens served as tooth-colored substructures. Three shades (neutral, light and warm) of resin cement try-in pastes (Variolink Esthetic LC) were used as the luting cement material. The color of each material group was measured before and after cementation using the three cement shades, and the CIE L^*a^*b^* coordinates were obtained with a spectrophotometer. Values for the translucency parameter (TP) and color change delta E (E) before (baseline) and after cementation of each specimen were determined. To compare differences among the material groups within each shade of cement and among various shades of cement within each material, the data were analyzed using one-way ANOVA and post hoc testing. RESULTS. Color coordinates L^*, a^* and b^* significantly changed after the application of try-in pastes relative to baseline values, with a noticeable decrease in lightness (L^*) (P < .05). A significant color change (ΔE) was observed in all tested materials after cementation, with ΔE values exceeding 3.3 (P < .05). Although TP changed after cementation for most materials tested, these changes were not statistically significant (P > .05). Shofu and Dima ceramics showed the lowest TP values, while Aidite and Prettau showed the highest TP values. For e.max, translucency decreased after cementation with neutral and warm shades, and it significantly increased after cementation with a light shade. CONCLUSION. The shade of cement significantly altered the final color of the ceramic veneer material to a level above the threshold at which the clinical perception of color change occurred (> 3.3). The TP was not influenced by the cement shade. The translucency levels of the novel ultratranslucent multilayer monolithic zirconia ceramics Aidite and Prettau were higher than that of the lithium disilicate e.max material.

• Science of Emotion and Sensibility
• /
• v.10 no.3
• /
• pp.289-297
• /
• 2007

Color image scale captures the knowledge of colorists and represents both adjectives and colors in the same adjective image scales in order to select color(s) corresponding to an adjective. Due to the difficulty of psychological experiment and statistical analysis, in general, only a limited number of colors are located in the color image scales. This can make color selection process hard especially to non-expert. In this paper, we propose an interpolation of color image scale based on the fuzzy K-nearest neighbor method, which provides continuous colors according to the coordinates of the image scales. The experimental results show that the interpolated image scales can be practically useful for color selection process.

• Journal of Information Display
• /
• v.12 no.1
• /
• pp.51-55
• /
• 2011

Efficient two-color-mixed white organic light-emitting diodes are presented herein by employing a sky-blue phosphorescent dopant of iridium(III)bis[4,6-(difluorophenyl)-pyridinato-N,$C^{2'}$]picolinate (FIrpic) and an orange phosphorescent dopant of bis(2-phenylquinoline)(acetylacetonate)iridium(III) ($Ir(phq)_2$acac) on the emissive layer. Very stable color variation under ${\Delta}$0.02 until a 5000 cd/$m^2$ brightness value was realized by efficient carrier control in a multi-stacked emitting layer of blue/red/blue colors. Maximum current and power efficiencies of 23.8 cd/A and 22.9 lm/W in the forward direction were obtained. With balanced emission from the two emitters, the white-light emission of high correlated color temperature of 7308K and the Commission Internationale de I'Eclairage coordinates of (0.30, 0.33) were achieved.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.57 no.2
• /
• pp.145-152
• /
• 2024

The present study investigated the digital color characteristics corresponding to different maturity stages and maturation levels of white croaker Pennahia argentatus specimens collected from the Southern Sea of South Korea. Maturity stages were determined using photomicrographs depicting ovarian developmental phases and compared with digital color values. The specimens ranged in body length from 21-36 cm, with mature ovaries observed within the 24-30 cm length range. To differentiate the maturing, mature, spawning, and post-spawning stages of the gonads, boundary lines were established based on specific coordinates. For the ovaries, a dividing line was drawn through (-10, -10) and (15, 5), described by the equation Y=3/5X-4; while for the testes, the line passed through (20, 0) and (0, 15), indicated by the equation Y=-3/4X+15. However, the visual determination of the maturity stages proved challenging due to overlapping color values. Consequently, this study underscores the efficacy of employing digital color measurements over subjective visual assessments to evaluate the maturity of white croaker gonads and offers more quantitative insights.