• 한국인쇄학회지
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• 제28권2호
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• pp.117-128
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• 2010

Advancements in digital image have put high quality digital camera into the hands of many image professionals and consumers alike. High quality digital camera images consist originally of raw which have a set of color rendering operation applied to them to produce good images. With color rendering, the raw file was converted to Adobe RGB and sRGB color space. Also color rendering can incorporate factor such as white balance, contrast, saturation. Therefore, in this paper we conduct a study on production of optimum profile considered color rendering in digital camera. To do the experiment, the images were Digital ColorChecker SG target and ColorChecker DC target. A profiling tool was ProfileMaker 5.03. The results were analyzed by comparing in color gamut of $CIEL^*a^*b^*$ color space and calculating ${\Delta}E^*_{ab}$. Also results were analyzed in terms of different $CIEL^*a^*b^*$ color space quadrants based on lightness, chroma.

• 조명전기설비학회논문지
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• 제17권6호
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• pp.1-6
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• 2003

본 연구에서는 광원의 색온도와 연색성의 차이에 의한 밝음의 느낌을 연구하기 위하여 이종 램프간, 또한 동종 램프 간의 비교 실험을 시각 대상물로 흑백 인쇄문자지와 색상지를 사용하여 수행하였다. 백열전구, 형광램프, 고압 나트륨램프, 메탈헬라이드램프, 무전극 방전램프를 대상으로 실험을 수행한 결과, 이종 광원의 경우 밝음의 느낌 비는 백열전구를 제외한 광원의 경우 대체적으로 평균연색계수에 비례하는 경향이 있으며, 모든 시험 대상 광원의 경우 색온도에 비례하는 것으로 나타났다.

• International Journal of Advanced Culture Technology
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• 제9권3호
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• pp.265-270
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• 2021

VR and AR contents provide a rich user experience [1]. Realistic content with human computer interaction and immersion provides an improved user experience, but there is a limit to producing all elements realistically. In this study, we propose a method to advance the rendering of immersive content using background color information [2]. First, the elements necessary for Kelvin temperature rendering are derived from the color and background as context elements, and the rendering effect has been realized in the soap bubble. For soap bubbles Kelvin temperature rendering, the average color of the background is extracted and the color with the highest similarity is applied by comparing the main color and Kelvin temperature.

• 한국광학회지
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• 제35권3호
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• pp.95-106
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• 2024

일반 백색 LED의 연색성을 보완하기 위해 적색 양자점을 선택적으로 활용함으로써 고연색성 조명을 구현하는 연구가 최근 활발하다. 본 논문에서는 최근 이루어지고 있는 원격 양자점 부품 연구 및 이를 활용한 고연색성 조명 개발의 현황에 대해 소개한다. 특히 양자점 부품이 배치되는 조명의 광구조 최적화에 있어서 중요하게 고려해야 할 다양한 요소를 집중적으로 논의함으로써 향후 고연색성 조명 연구의 방향 및 전망까지 다루고자 했다.

• 산업경영시스템학회지
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• 제46권3호
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• pp.59-68
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• 2023

Currently, yellow phosphor of Y3Al5O12:Ce3+ (YAG:Ce) fluorescent material is applied to a 450~480nm blue LED light source to implement a white LED device and it has a simple structure, can obtain sufficient luminance, and is economical. However, in this method, in terms of spectrum analysis, it is difficult to mass-produce white LEDs having the same color coordinates due to color separation cause by the wide wavelength gap between blue and yellow band. There is a disadvantage that it is difficult to control optical properties such as color stability and color rendering. In addition, this method does not emit purple light in the range of 380 to 420nm, so it is white without purple color that can not implement the spectrum of the entire visible light spectrum as like sunlight. Because of this, it is difficult to implement a color rendering index(CRI) of 90 or higher, and natural light characteristics such as sunlight can not be expected. For this, need for a method of implementing sunlight with one LED by using a method of combining phosphors with one light source, rather than a method of combining red, blue, and yellow LEDs. Using this method, the characteristics of an artificial sunlight LED device with a spectrum similar to that of sunlight were demonstrated by implementing LED devices of various color temperatures with high color rendering by injecting phosphors into a 405nm deep blue LED light source. In order to find the spectrum closest to sunlight, different combinations of phosphors were repeatedly fabricated and tested. In addition, reliability and mass productivity were verified through temperature and humidity tests and ink penetration tests.

• 한국재료학회지
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• 제27권6호
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• pp.312-317
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• 2017

In the construction of a white LED, the region of the red emission is a very important factor. Red light emitting materials play an important role in improving the color rendering index of commercial lighting. These materials also increase the color gamut of display products. Therefore, the development of novel phosphors with red emission and the study of color tuning are actively underway to improve product quality. In the present study, heuristic algorithms were used to search for phosphors capable of increasing the color rendering index and color gamut. Using a heuristic algorithm, the phosphors that were identified were $SrGe_4O_9:Mn^{4+}$ and $BaGe_4O_9:Mn^{4+}$. Emission spectra study confirmed that these phosphors emit light in the deep red wavelength region, which can fulfill the requirement for the improvement in color rendering index and color gamut for a white LED.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.961-965
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• 2006

White organic LED spectrum for lighting and displaying should be designed for high luminous efficiency as well as good chromaticity coordinate, pleasant correlated color temperature and color rendering. A program based on Matlab was made to make these calculations convenient. The chromaticity coordinate and luminous efficiency was calculated according to the CIE 1931 colorimetric system, while the correlated color temperature(CCT) was calculated based on CIE 1960 UCS diagram. The color rendering characteristics were evaluated according to the CIE Color Rendering Index (CRI), using Ra, Ri and ${\bigtriangleup}E$ from the 14 color samples defined in CIE13.3.

• 대한건축학회논문집:계획계
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• 제35권1호
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• pp.99-106
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• 2019

This study aims to recommend the proper Color rendering index (CRI), the Correlated Color Temperature (CCT), and illuminance levels of Light-Emitting Diode (LED) lighting based on the analysis of the criteria of the current CRI, the CCT, and illuminance levels in merchandising spaces with LED lighting conditions. It would be a basic material to apply in line with user preference for LED merchandising lighting. To this end, it examines relevant literature review on the experiments designed to test whether lighting characteristics affect brightness perception, color appearance, and pleasantness. Highly saturated colors appear brighter than low saturated colors. Two lighting applications - grocery and clothing shop - were created in elaborating the effect of LED lighting characteristics of CRI on color appearance and the CCT and illuminance on pleasantness. The findings show that the criteria of CIE Ra<80 are appropriate to provide better color appearance of illuminated products in terms of LED lighting that can enhance color saturation, particularly for the red color. Furthermore, 2700 K and less than 500 lux for grocery, 4000 K and more than 500 lux for clothing shop are found to be the proper the CCT and illuminance levels respectively to bring better preference under LED lighting.

• 조명전기설비학회논문지
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• 제28권3호
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• pp.1-6
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• 2014

We measured color rendering index(CRI) of a LED lamp for lighting for aging-time. We chose bulb type white LED lamp six samples and halogen lamp one sample and applied 220V, 60Hz to all the samples for 1,000hours at ordinary temperature. The CRI was measured every 20hours and the CRI change of the LED lamp was compared with the halogen lamp's CRI change. As time goes, efficiency of the halogen lamp decreased and the CRI maintained uniformly. The other hand, efficiency of the LED lamp decreased but the CRI increased. The CRI of the LED lamp has been stabilized since 600hours. The CRI change of the LED lamp was analyzed with a spectrum, color coordinate and color temperature.

• 한국컴퓨터그래픽스학회논문지
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• 제27권5호
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• pp.25-32
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• 2021

직접 볼륨 렌더링은 볼륨 표면의 연산 없이 2차원 공간에 투영하여 렌더링 한다. 직접 볼륨 렌더링에서 전이함수(TF)는 볼륨에 색상과 투명도와 같은 광원 특성을 할당하는데 활용된다. 하지만 초보자가 TF를 조작하여 볼륨데이터를 파악하고 색상을 할당하기까지 오랜 시간이 필요합니다. 본 논문에서는 직관적인 볼륨 렌더링을 위해 인터넷에서 수집한 이미지를 사용하여 TF에 볼륨의 색상을 매핑하는 접근 방식을 제안한다. 또한 우리는 K-means 클러스터링을 활용한 색상 추출 방법을 토의한다.