• 제목/요약/키워드: Lab color difference

검색결과 58건 처리시간 0.026초

명도 수준에 다른 목표 샘플의 색차 (Color Differences of Standard Samples according to Their Lightness Levels)

  • 김정렬;이승준;김삼수
    • 한국염색가공학회지
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    • 제17권2호
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    • pp.19-25
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    • 2005
  • A colour-difference formulae would be based on a colour appearance model, but, So far, most colour-difference formulae in common use are based on empirical fits to data. Therefore, of the many proposed, none are completely satisfactory but advances have been made in recent years. A new color-difference data set has been produced with the aims of making a comparison of the advanced CIE Lab formulae as well as confirming the effect of color-difference. 416 low lightness pairs that have only lightness-difference were produced for evaluation of CIE Lab-based formulae on lightness-difference from glossy polyester fabric. The standard color-difference pair was prepared and used. It was neutral grey sample pair that has only lightness difference. The standard pair was used to investigate lightness tolerances. And grey-scale method used to evaluate visual assessment. CIE Lab coordinates of the samples were measured using a X-Rite 8200 spectrophotometer. Visual assessments were carried out using Gretag Macbeth The Judge II Light Booth. A study of color tolerances at low lightness was carried out and get avaliable some results.

Investigation of muscle-specific beef color stability at different ultimate pHs

  • Wu, Shuang;Han, Jina;Liang, Rongrong;Dong, Pengcheng;Zhu, Lixian;Hopkins, David L.;Zhang, Yimin;Luo, Xin
    • Asian-Australasian Journal of Animal Sciences
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    • 제33권12호
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    • pp.1999-2007
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    • 2020
  • Objective: This study was aimed to investigate the muscle-specific beef color stability at normal and high ultimate pHs. Methods: The impact of muscle (Longissimus lumborum [LL] vs psoas major [PM]) and pH (normal ultimate pH [Np] vs high pH dark cutting beef [Hp]) on color stability, indicated by basic color traits, metmyoglobin reducing activity (MRA) and oxygen consumption (OC), as well as the lipid oxidation, were determined over 7 days of display at 4℃. Results: Hp-LL had the highest pH (6.92), followed by Hp-PM (6.01), Np-PM (5.76), and Np-LL (5.52). Hp-LL had increased (p<0.05) a, chroma and % oxymyoglobin during display. Hp-LL also had the highest metmyoglobin (MMb) reducing activity and OC among all the samples, thus, the greatest color stability, although very dark throughout storage, with lowest values for lightness (L) and yellowness (b). Np-LL also exhibited relatively high color stability, as a result of its lower % MMb and OC and higher MRA than psoas muscle samples. The 0.2 unit difference of the pH between Hp and Np psoas muscle, resulted in the difference of the color intensity, not the color stability. Interestingly, high pH psoas muscle (Hp-PM) did not have better color stability than Np-PM, and in fact had lower color stability than even Np-LL. The similar level of OC and lipid oxidation cannot explain the difference in color stability between Hp-PM and Np-LL. Conclusion: The Hp does not always show better color stability compared with Np beef, which depends on the muscle type. The balance of MRA and OC is important to keep the color in great intensity and stability in the meantime.

도포법 및 침전법을 이용한 지르코니아의 색조 재현성 비교 연구 (Comparative study of color reproducibility of zirconia using a dipping method and coating method)

  • 이희정;김재홍;김웅철;김지환;김혜영
    • 대한치과기공학회지
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    • 제35권3호
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    • pp.185-192
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    • 2013
  • Purpose: The aim of this study was to compare with color reproducibility of the coating method and dipping method using a colour liquid. Methods: Two groups of square-shaped specimens ($10mm{\times}10mm$ in diameter, 1.5mm thickness) were prepared for analysis(n=15/group). The CM(Coating Method) group was fabricated as full zirconia specimens with the coating coloring method and Group DM(Dipping Method) was prepared as specimens of 0.7 mm-thick zirconia plate using the dipping coloring method and veneered with 0.8mm-thick porcelain. Color parameters were measured with ShadeEye $NCC^{(R)}$ spectrophotometer and color differences were calculated using the equation ${\Delta}E^*= \{({\Delta}L^*)^2+({\Delta}a^*)^2+({\Delta}b^*)^2\}^{1/2}$. Non-parametric statistical methods, the Mann-Whitney test, and the Kruskal-Wallis test were used to analyze the data. Type one error rate was set at 0.05. Results: Color difference values larger than 7 were observed between specimens with the coating method and the dipping method, which were detectable difference in a clinical setting. Conclusion: Cautious application of the coating coloring method in a clinical setting and further researches to standardize the coating method are needed.

인지적 색 차이 기반의 이미지 품질 평가 기법 및 왜곡 종류에 따른 평가 시스템 제안 (Perceptual Color Difference based Image Quality Assessment Method and Evaluation System according to the Types of Distortion)

  • 이지용;김영진
    • 정보과학회 논문지
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    • 제42권10호
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    • pp.1294-1302
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    • 2015
  • 현재까지 인간 시각 체계를 정확하게 반영하기 위한 이미지 평가 기법에 대한 연구가 많이 이루어져 오고 있다. SSIM은 인간의 시각 체계가 이미지의 구조적 정보에 예민하다는 점을 이용하여 구조적 정보를 이용하여 이미지를 평가하는 대표적인 인간 시각 체계를 만족시키는 평가 기법이다. 하지만 SSIM은 이미지의 색 차이를 반영하지 못하는 문제가 있다. 이러한 문제를 해결하기 위해, HSI 색 공간을 활용한 SHSIM 기법이 제안되었으나 두 컬러 이미지 간 인지적 색 차이를 충분히 반영하지는 못하고 있다. 본 논문에서는 CIE Lab 색 공간을 도입하여 대응 되는 픽셀들의 인지적 색 차이를 계산하여 이미지 평가에 활용하는 방법을 제안한다. 그리고 연구를 더 확장하여, SVM 분류기를 활용하여 왜곡 종류에 따라 최적의 평가 수식을 적용하는 최적화 시스템을 제안한다. 제안하는 기법을 평가하기 위해, 이미지 평가분야에서 가장 많이 알려진 LIVE 데이터베이스를 사용하였으며 네 종류의 평가 기준들을 이용하였다. 실험 결과에서는 제안하는 기법이 다른 기법들보다 인간 시각 체계와 더 상관성이 높다는 것을 보여준다.

A Quantitative Measure in Uniform Color Space for Dynamic False Contours on PDP

  • Park, Seung-Ho;Kim, Choon-Woo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.617-620
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    • 2002
  • Quantitative analysis of dynamic false contours on PDP is essential to evaluate the performance of algorithms for false contour reduction. It also serves as an optimization criterion for selecting the subfield pattern. In this paper, a color difference in uniform color space is defined as a new measure for dynamic false contours. Unlike the measures in previous works, it accounts for the channel dependencies among the RGB color channels.

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제천출토 청송심씨 출토유물의 보존처리 (A Study on the Conservation of Lady Shim's Costume Excavated in Jecheon Province)

  • 박봉순;이목근;장인우
    • 복식
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    • 제65권7호
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    • pp.47-59
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    • 2015
  • This paper studies the conservation treatment of Lady Shim's costume, which was excavated in Jecheon Province in 2012. There were the significant problems, which were encountered in the treatment of the costume ; First the Jeogoris were transformed during the excavation, Second fibers were seriously deteriorated, Third most of the fabrics such as Chusa were readily deformed. To overcome these problems and to secure stability in the conservation treatment, we decided to alternate between two different washing methods ; dry cleaning by n-hexane and wet cleaning by water. The costume shape was recovered by steaming and by swelling with Hanji(Korean traditional paper). The combined cleaning method proved to be relatively efficient and stable. In addition, the shape of Chusa was well preserved by dry cleaning.(using n-hexane also solved the problem of bad smell after washing with organic solvents.) The effects of the conservation treatment on the excavated costumes could be seen in the change of Lab color difference. Washing made the distribution of Lab color difference narrower, which may suggest that the impurities on the fiber was removed by washing. In addition, the value of L was greater than a-value and b-value after the treatment. This result indicates that the change of value represents the change of color difference by cleaning.

치과용 모형재 색상에 따른 디지털 모형의 체적 안정성 연구 (The study on the dimensional stability of digitized dental stone replicas according to difference color of gypsum materials)

  • 최석순;김기백;이경탁;전진훈;김재홍
    • 대한치과기공학회지
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    • 제34권4호
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    • pp.369-377
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    • 2012
  • Purpose: The aim of study was to compare the dimensional stability of digitized dental stone replica using different color of gypsum materials using a white light scanner with three-dimensional software. Methods: A master model(500B-1, Nissin dental product, Japan) with the prepared lower full arch tooth was used. Several type IV stones(white, yellow, green) were used for 30 stone casts(10 casts each) duplicated a master model of mandible. The master model and the replicas were digitized with the non-contacting white light scanner to create 3-dimensional digital models. The linear distance between the reference points were measured and analyzed on the Delcam Copycad$^{(R)}$(Delcam plc, UK) 3D graphic software. One-way analysis of variance(ANOVA) combined with a Tukey multiple-range test were used to analysis the data(${\alpha}$=0.05). Results: There were considerable differences in mean values between gypsum materials within each color(white, yellow, green), and this difference was statistically significant, p=0.001. Conclusion: Digitization of dental materials on optical scanner was affected by color. Three different color of gypsum materials showed clinically acceptable accuracies of full arch digital model produced by them. Besides, these results will have to be confirmed in further clinical studies.

시판차류제품(市販茶類製品)의 Hunter-Lab Tristimulus Colorimeter에 의한 색상(色相) 평가(評價) (Color Evaluation of Commercial Dehydrated Tea-products by Hunter-Lab Tristimulus Colorimeter)

  • 박길동;최진호;성현순
    • 한국식품영양과학회지
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    • 제11권1호
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    • pp.25-30
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    • 1982
  • 시판차류기호식품(市販茶類嗜好食品)의 관능적(官能的) 평가(評價)와 이들 제품(製品)의 품질관리적(品質管理的) 측면(側面)에서 중요시되는 색도(色度)의 지표(指標)를 조사코저 Hunter-lab tristimulus colormeter를 이용(利用)하여 제품(製品)의 입도(粒度), 밀도(密度), 및 탈흡습(脫吸濕)이 색도(色度)에 미치는 영향을 조사하였다. 1. 제품(製品) 사이에는 입도(粒度)의 크기와 색도(色度)에서 특별한 유사성(有意性)이 인정되지 않았으며, 홍삼정분(紅蔘精粉)의 경우 입도(粒度)가 작아질수록 L,a,b 치(値)가 증가하고, X,Y,Z 치(値)에서는 X, Y 치(値)는 증가하는 경향이었으나 Z 치(値)는 일정치 않았다. 2. 시판차류기호식품(市販茶類嗜好食品) L치(値) 범위는 32.8$\sim$48.0이었고 a 치(値)는 3.9$\sim$10.4, b 치(値)는 5.6$\sim$18.0이었으며 대부분의 제품(製品)이 주황색색소계(朱黃色色素系)에 속하는 것으로 나타났다. 3. 제품(製品)의 밀도(密度)는 0.232$\sim$0.898 g/ml의 범위 내에 있었으며 밀도가 클수록 L치(値)가 가하는 경향이었다. 4. 제품별(製品別) a/b치(値)는 생강차를 제외하고 0.61$\sim$0.98의 범위 내에 집중되어 있었으며 총색도(總色度)의 차(差)($\Delta$E) 및 채색도(彩色度)의 차(差)($\Delta$C)가 작은 제품(製品)일수록 색상(色相)의 안정성(安定性)이 인정되었다. 5. 각제품(各製品) 사이에는 흡습(吸濕) 및 탈습(脫濕)에 의한 색상변화(色相變化)는 유의성이 없었다. 6. 광파장(光波長)에 따른 제품별색도(製品別色度)는 생강차, 쌍화차 및 탱이 녹적색계색소(綠赤色系色素)가 가장 높아 녹적색색소계(綠赤色色素系)인 반면 다른 차류제품(茶類製品)은 X,Y,Z 치(値)가 거의 비슷한 경향을 나타냈다.

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A Study of Onion Skin Pigments in the Extracting Solvents and Residual Pigments after Dyeing the Textiles

  • Bae, Soon-Ei
    • 패션비즈니스
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    • 제13권3호
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    • pp.109-117
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    • 2009
  • To set up the outstanding and scientific dyeing method in making the condensed liquid of pigment obtained from onion skins and the improved reliability, the following basic experiments were performed. The pigment was extracted in the distilled water at $70^{\circ}C$ and methanol at room temperature and then it was analyzed with LC/MS/MS system (Liquid Chomatography/Mass Spectroscopy/Mass Spectroscophy, LIQ Advantage Max, Thermo Finnigan, USA) for its pigmental characteristics. The unrefined silk and refined silk were dyed by making use of the derived pigment in such a way. The chromameter (CR-200, Minolta, Japan) was used to measure the change in surface color in textiles to be dyed by the extracting condition and the color difference ${\Delta}E$ was determined according to the color difference formula CIE LAB through measuring the psychometric lightness L* and chromaticity coordinates a* and b*.

지르코니아 코어 두께에 따른 전부도재관의 상부도재 축성방법이 보철물 색조에 미치는 영향 (The Effect of Veneering Techniques on the Color Parameters of Y-TZP Based All Ceramic Restoration of Varying Ceramic Core Thickness)

  • 허성윤;손호정;김혜영;김재홍
    • 치위생과학회지
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    • 제12권2호
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    • pp.123-129
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    • 2012
  • 이 연구에서는 지르코니아 코어의 두께를 달리 제작하여 동일한 색조의 상부도재를 축성함에 있어 제작방법을 다르게 하여 두 상반된 시편을 각각 분광측색장치를 이용하여 CIE $L^*,a^*,b^*$ 색체계로 산출하여 객관적으로 색차를 비교, 분석하여 다음과 같은 결론을 얻었다. 1. 지르코니아 코어의 두께가 두꺼워 지고 상부도재의 두께가 얇아지면서 $L^*$ 값의 수치는 높아지며 $a^*,b^*$ 값은 낮아지는 경향을 띠었다. 상부도재 축성방법을 다르게 제작한 시편에서도 같은 결과를 보였다. 동일한 색조 시편에서 HP군은 PST군에 비해 $L^*$ 값의 수치는 낮게 측색되어 어두운 경향을 보였으며 $a^*,b^*$ 값도 낮은 수치를 보여 황색의 경향을 띠었다. 2. HP군, PST군 모두 동일한 색조에서 지르코니아 코어 두께와 상부도재 제작방법 간에 교호작용은 없었다(P=.083). 지르코니아 코어의 두께에 따라서는 통계적으로 유의한 차이는 존재하였으며(P=.001), 두께가 0.3 mm의 시편 A1, A2 색조에서 색차 값($E^*$)은 3.7 이상으로 나타났고, 그 이외 시편에서는 3.7 이하로 분석되어 임상가능 허용치로 나타났다. 이상의 결과로 볼 때 지르코니아를 이용한 전부 도재관 제작 시 같은 색조의 재료 일지라도 제작방식과 상부도재의 재료에 따라 색차 값이 존재하므로 이를 감안하여 보철물 제작에 사용해야 할 것으로 사료되며, 특히 코어의 두께가 얇은 보철물에서는 임상 허용치 이상의 색차 값을 보이므로 코어의 두께를 좀 더 추가하여 설계한 보철물이 바람직하다고 생각된다.