Quantifying Visual Specular Gloss Scale

Youngshin Kwak(곽영신),Hyun Jin Park(박현진),Ki-Hyeong Im(임기형) 한국색채학회 2011 한국색채학회 논문집 Vol.25 No.3

현재 시중에 판매되는 대부분 전자 제품의 표면은 광택이 높은 편이나, 색 품질 관리를 위해 사용하는 색차식들은 대부분 광택이나 테스쳐가 없는 평면에 표현된 색을 이용하여 개발된 것들로 기존의 색차식을 이용하여 광택이 있는 제품의 색관리를 하는 데 한계가 발생한다. 이 때문에 색채과학 분야에서는 색 뿐 아니라 광택이나 텍스쳐까지 정량화가 가능한 시감 예측 모델에 관한 연구가 큰 관심을 받고 있다. 본 연구에서는 시감 예측 모델 개발을 위한 첫 단계로 우선적으로 측정된 광택과 인지된 시감 광택간의 상관관계를 조사하였다. 다양한 수준으로 UV 코팅된 폴리카보네이트 샘플들을 이용하여 두 세트의 광택 실험 데이터를 수집하였다. 첫 번째 세트는 11 단계의 서로 다른 광택을 갖는 흰색 및 검정색 샘플들로, 두 번째 세트는 21 단계의 흰색 및 검정색 샘플들로 구성되었다. 샘플들을 D65 광원이 켜진 관측 상자 안에 제시한 후 관찰자들에게 0에서 100 사이의 값으로 인지된 광택 정도를 대답하게 하였다. 각 실험에는 10명 내외의 관찰자들이 참여하였다. 실험 데이터 분석 결과 인지된 광택 정도는 실험 시 함께 제시된 주변 샘플들의 광택정도에 상관없이 일정하게 나타났다. 이는 시각적으로 인지되는 광택은 물리적으로 정의되는 표면에서 발생하는 정반사 정도가 아니라 사람들이 표면 특성을 인지하는데 이용하는 시각 정보로 표면 고유의 절대적인 특성인 것으로 판단된다. 또한 물리적으로 동일한 광택값을 갖는 샘플이다 하더라도 검정색 샘플이 흰색 샘플보다 더 광택이 높아 보이는 것으로 나타났다. 본 연구에서 얻어진 시감 광택 데이터는 향후 광택 예측 모델 개발 등에 활용될 수 있을 것이다. Current state-of-art color-difference equations for color quality control are developed mainly for matte surfaces without any gloss or textures. However, most of the home appliances or electrical devices available today have glossy appearance limiting the accuracy of surface color difference prediction. Therefore new visual appearance model development will be the next goal for the color scientists including not only the color but also other surface appearances such as gloss or texture. In this study, as a first step of surface appearance model development, the relationship between the perceived gloss and the measured gloss were investigated. Two sets glossiness data were obtained for the polycarbonate (PC) surfaces with the different levels of UV clear coating. The frist set came from the eleven black and white samples with different gloss levels and the second data set was collected using twenty one black and white samples. The samples were shown in the viewing booth illuminated with D65 simulator and the observers were asked to scale the perceived glossiness between 0 and 100 for black and white samples. Around ten observers participated each experiment. The experimental results showed that the observers can judge a glossiness of a sample consistently regardless the gloss level of the neighboring samples displayed together. It suggests that glossiness is an intrinsic and absolute visual attribute people use to judge the surface appearance. Also it is confirmed that black samples look glossier than white samples having the same physical gloss value. The experimental data in this study could be used to develop mathematical glossiness prediction model.

RGB LED 조명 스펙트럼에 따른 CIECAM02 색공간에서의 NCS 칼라 차트 색변화 분석

곽영신(Youngshin Kwak),유찬양(Chanyang You) 한국색채학회 2011 한국색채학회 학술대회 Vol.2011 No.5

RGB LED 조명의 스펙트럼 분포에 따라 실내의 색감이 얼마나 영향을 받는 가를 NCS 앨범에서 R, Y, G, B 색상 페이지의 189개 샘플들을 이용하여 조사하였다. RGB 별 10m 내외로 서로 다른 파장 스펙트럼을 갖는 두 종류의 RGB LED 조명에서 테스트 샘플들의 색상을 CIECAM02 명도, 채도, 색각으로 계산하여 D65 광원에서의 색과 비교해본 결과 LED2 조명 하에서 다른 조명들보다 R 및 G 색상 영역의 샘플들은 약 20% 정도 높은 채도를 갖는 것으로 나타났다. 색상 변화는 두 LED 조명 모두 고명도 저채도 샘플들에서 더 크게 나타난 반면 명도 변화는 거의 없었다. 이는 조명에 스펙트럼 변화에 따른 색변화 크기가 샘플의 색에 따라 다르게 나타나며 작은 조명 스펙트럼 변화에도 공간의 색감은 크게 영향을 받을 수 있다는 것을 의미한다.

불평등 사회 속 공정 담론의 다차원성 : 청년 공정 관련 신문사설에 대한 비판적 담론분석

곽영신(Kwak, Youngshin),류웅재(Ryoo, Woongjae) 한국언론학회 2021 한국언론학보 Vol.65 No.5

This study utilizes a critical discourse analysis of youth-related fairness discourse appearing in a series of newspaper editorials during the Moon Jae-in regime, from the beginning of his presidency. Specifically, this study examines how fairness discourse in the field of education and labor, as a representative social resource distribution channel, is articulated in the public forum of the media. In particular, based on the diagnosis that the meaning of fairness discourse in Korean society is distorted upon the interests and goals of each class and groups, we tried to examine the complex and plural nature of the concept of fairness in a context-specific way. First, fairness discourse is embraced by the ideology of meritocracy that emphasizes the principle of equity and procedural fairness. However, this view can conceal injustice, resulting from structural discrimination and exploitation. Second, the media has expanded and reproduced the discourse of fairness viewed from the perspective of the upper class and the powerful. As a result, it justifies a ‘winner takes all’ logic and system of domination through existing competition rather than resolving structural injustice. Third, rather than presenting in-depth coverage of fairness discourse to the public, the media tends to serve and immerse itself in the interests of each political camp and use them as a political tool to amplify conflicts. Furthermore, since corruption and foul play are still prevalent in Korean society, the desire for meritocracy and fairness discourse is growing. On the other hand, although the phenomenon of neo-nepotism due to the continuation of the meritocracy system is emerging in Korean society, there is still a social imagination and hope for the ideal meritocracy.

Perceptual difference between the discomfort luminance level and the brightness of a head-mounted display (HMD)

Ha Hyeyoung,Kwak Youngshin,Kim Hyosun,Seo Young-jun,Jo Sung-Chan 한국정보디스플레이학회 2021 Journal of information display Vol.22 No.3

A psychophysical experiment was conducted to compare the discomfort luminance level and the brightness of a head-mounted display (HMD). The results showed that as the size of the HMD stimulus increased, both the discomfort luminance level of the HMD and the brightness of the HMD decreased, but the influence of the size change was more dramatic on the discomfort luminance level than on the brightness. This study showed that to provide a comfortable luminance level for HMDs, the adaptation luminance level and the size of the HMD stimulus should be considered. However, it cannot be predicted in terms of brightness.

The Effects of Neighboring Colors on Affectivity

( Semin Oh ),( Youngshin Kwak ) 한국감성과학회 2014 춘계학술대회 Vol.2014 No.-

When people see a color in a daily life, people recognize the color with various neighboring colors behind, not just one color independently. So these neighboring colors can affect the affectivity. However previous researches on color affectivity are based on the single color patch experiment. The aim of this study is to investigate the effects of neighboring colors on color affectivity when seeing a color. Firstly, 10 test colors were selected. 10 test colors were distributed to cover wide color gamut. Secondly, we made 3 background conditions. One is uniform gray background and another contains saturated 24 neighboring colors and the other contains desaturated 24 neighboring colors. To evaluate affectivity, 10 adjective sets were used. Those were ``Warm-Cool``, ``Heavy-Light``, ``Modern-Classic``, ``Clean-Dirty``, ``Active-Passive``, ``Hard-Soft``, ``Tense-Relaxed``, ``Fresh-Stale``, ``Masculine-Feminine``, ``Like-Dislike``. The experiment was done under a viewing booth with an illuminant D65 in a dark room. Ten subjects participated in the experiment and each participant evaluated an affectivity of each test color using 7-point Likert scales. As a result, there was no strong relationship between neighboring color condition and color affectivity. It shows that the previous color affectivity results using a single color patch can be applied to the complex color condition.

The Effects of Neighboring Colors on Affectivity

Semin Oh,Youngshin Kwak 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.5

When people see a color in a daily life, people recognize the color with various neighboring colors behind, not just one color independently. So these neighboring colors can affect the affectivity. However previous researches on color affectivity are based on the single color patch experiment. The aim of this study is to investigate the effects of neighboring colors on color affectivity when seeing a color. Firstly, 10 test colors were selected. 10 test colors were distributed to cover wide color gamut. Secondly, we made 3 background conditions. One is uniform gray background and another contains saturated 24 neighboring colors and the other contains desaturated 24 neighboring colors. To evaluate affectivity, 10 adjective sets were used. Those were ‘Warm-Cool’, ‘Heavy-Light’, ‘Modern-Classic’, ‘Clean-Dirty’, ‘Active-Passive’, ‘Hard-Soft’, ‘Tense-Relaxed’, ‘Fresh-Stale’, ‘Masculine-Feminine’, ‘Like-Dislike’. The experiment was done under a viewing booth with an illuminant D65 in a dark room. Ten subjects participated in the experiment and each participant evaluated an affectivity of each test color using 7-point Likert scales. As a result, there was no strong relationship between neighboring color condition and color affectivity. It shows that the previous color affectivity results using a single color patch can be applied to the complex color condition.

Time-course analysis of change in display color-appearance based on ambient light change

Yoon Seonyoung,Kwak Youngshin,Kim Hyosun 한국정보디스플레이학회 2023 Journal of information display Vol.24 No.2

This study investigates the time course of changes in display color appearance according to changes in ambient lighting. Psychophysical experiments were conducted to observe brightness under lighting transitions in illuminance and the perceived white point under lighting transitions in correlated color temperatures. The result shows that significant change in the color appearance occurs immediately after ambient lighting changes. In addition, the initial change in color appearance depends on the lighting transition characteristics. The continuous change in color appearance was observed when ambient lighting was changed to brighter or lower CCT. On the other hand, a significant abrupt change at the initial stage of adaptation was observed when ambient lighting was changed to darker or higher CCT.

Warm-Cool Emotions of LED Lightings around 5,000K

Semin Oh,Youngshin Kwak 한국조명·전기설비학회 2017 조명·전기설비학회논문지 Vol.31 No.8

In this study, warm-cool feelings of near-white lightings were investigated after the subjects’ eyes being adapted to 5,000K. The psychophysical experiment was carried out in a dark room using 5 channels LED lighting booth. In the experiment, total of 48 test lightings around 5,000K were generated using the booth. Total of 20 subjects evaluated warm-cool feelings of each test lighting. The results showed that lower CCT tended to have ‘Warm’ feeling, while higher CCT tended to arouse ‘Cool’ feeling. When CIECAM02 H is in the range of 0-100 and 380-400, ‘Warm’ feeling was strongly evoked and when H is in the range of 250-300, ‘Cool’ feeling was strongly aroused. Also, when test lightings have same hue, the one having higher chroma aroused stronger feeling on either ‘Warm’ or ‘Cool’. Emotion model test results showed Koo’s model, which is based on lighting colors, showed better performance than the model developed based on color patches.

Preference of the Various Primary Colors on the Non-Transparent Display and Transparent Display

Hyeyoung Ha,Youngshin Kwak,Hyosun Kim,Young-jun Seo,Won-Sang Park 한국색채학회 2017 AIC 2017 Jeju Vol.2017 No.10

The preferred primary colors of the transparent display and non-transparent display were investigated under 3000K surround light correlated color temperatures (CCTs). The psychophysical experiment was conducted on the 24-inch LCD display and two different display (the non-transparent display and 40% transparent display) were simulated to have three different display CCTs (3000, 5000 and 6500K). Red apple, green grass and blue sky images were selected as the test image and each image was manipulated to have various primary chromaticities. About 15, 18, 15 chromaticity coordinates were selected to simulate the red, green and blue primary colors respectively. Twenty subjects participated in the psychophysical experiment and they were asked to answer the preference of each image using 7-points Likert-scale. From the psychophysical experiment result, two major findings were discovered. First, the Red primary color having the longer dominance wavelength is preferred regardless of the display CCT and display type. Second, there is no huge image preference difference between the transparent display and the non-transparent display.

미디어에 따른 단색과 배색의 색감정 변화

유찬양(Chanyang You),곽영신(Youngshin Kwak) 한국색채학회 2010 한국색채학회 학술대회 Vol.2010 No.5