• Title/Summary/Keyword: Chromaticity image

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Color Edge Detection using Variable Template Operator

  • Baek Young-Hyun;Moon Sung-Ryong
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.6 no.2
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    • pp.116-120
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    • 2006
  • This paper discusses an approach for detecting a new edge in color images. The color image is to be represented by a vector field, and the color image edges are detected as differences in the local vector statistics. This method is based on the calculation for the vector angle between two adjacent pixels. Unlike Euclidean distance in RGB space, the vector angle distinguishes the differences in chromaticity, independent of luminance or intensity. The proposed approach can easily accommodate concepts, such as variable template edge detection, as well as the latest developments in vector order statistics for color image processing. In this paper, it is used not a conventional fixed template operator but a variable template operator The variable template is implemented and experimental results for digital color images are included.

Digital Camera Characterization Method under Multiple Illuminants (다중 광원에서의 디지털 카메라 특성화 방법)

  • Yoon, Chang-Rak;Cho, Maeng-Sub
    • Proceedings of the Korea Information Processing Society Conference
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    • 2000.10b
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    • pp.871-874
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    • 2000
  • 디지털 카메라(Digital Camera)와 같은 휴대형 영상 입력 장치(Portable Image Input Device)는 스캐너 (Scanner)와 달리 3 차원의 피사체(Object)를 디지털 영상으로 생성할 수 있고 다양한 조명 환경(Illuminant)에서 사용할 수 있다는 이유로 많은 응용 분야에서 활발하게 사용되고 있다. 그러나, 정확한 색 재현(Color Reproduction)을 위한 기존의 디지털 카메라 특성화 방법(Digital Camera Characterization Method)은 생성된 영상의 조명 정보를 고려하지 않은 상태에서 색 변환 행렬을 생성하므로 다양한 조명 환경 변화에 대해 적응적으로 대처하지 못하는 단점이 있다. 본 논문에서는 디지털 카메라가 생성하는 영상의 rgb 색도를 이용하여 색도 평면에 색도 다각형(Chromaticity Polygon)을 구성하고 각 색도 다각형들간의 포함 관계에 따라 조명 정보를 평가함으로써 조명색(Illuminant Color)의 변화에 따른 인간 시각 시스템(Human Visual System)의 색 불변성(Color Constancy)을 재현할 수 있는 디지털 카메라 특성화 방법을 제안한다.

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An Analysis of Luminance and Chromaticity on Outdoor Lighting of Historic Buildings -focused on Namdaemun and Kwanghwamun- (휘도와 색도측면에서 본 역사적 건축물의 야간경관조명 분석 -남대문과 광화문을 중심으로-)

  • 안현태;김정태
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.1
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    • pp.36-43
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    • 2001
  • Recently, outdoor lighting of buildings has bemIre activated in national level of Korea. Therefore, this study aims to analyze the outdoor ljghting effect of historic buildings with particular reference to two traditional gates architecture - Namdaemtul and Kwanghwamun For the purpose, luminance and chromaticity of outdoor lighting are measured. The results of the study are as follows; $\circled1$ Outdoor lighting of the historic buildings were mainly illuminated by the floodlights. In addition, up-lighting and accent lighting were locally used. $\circled2$ Basements and rooflines were specially emphasized, and they represented the night image of historical buildings. $\circled3$ Chromaticity distribution of historical building was wlute during the day. However, it was yellow dL1Jing the night due to the color and color temperature of outdoor lighting.ghting.

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Loitering Behavior Detection Using Shadow Removal and Chromaticity Histogram Matching (그림자 제거와 색도 히스토그램 비교를 이용한 배회행위 검출)

  • Park, Eun-Soo;Lee, Hyung-Ho;Yun, Myoung-Kyu;Kim, Min-Gyu;Kwak, Jong-Hoon;Kim, Hak-Il
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.21 no.6
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    • pp.171-181
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    • 2011
  • Proposed in this paper is the intelligent video surveillance system to effectively detect multiple loitering objects even that disappear from the out of camera's field of view and later return to a target zone. After the background and foreground are segmented using Gaussian mixture model and shadows are removed, the objects returning to the target zone is recognized using the chromaticity histogram and the duration of loitering is preserved. For more accurate measurement of the loitering behavior, the camera calibration is also applied to map the image plane to the real-world ground. Hence, the loitering behavior can be detected by considering the time duration of the object's existence in the real-world space. The experiment was performed using loitering video and all of the loitering behaviors are accurately detected.

Color change of dried laver according to heating conditions (가열조건에 따른 마른김의 색택 변화 연구)

  • Kyoung-In Lee;Geun-Jik Lee;Young-Seung Yoon
    • Journal of Marine Bioscience and Biotechnology
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    • v.16 no.1
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    • pp.19-25
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    • 2024
  • To verify the color change in dried laver postproduction during the heating process, chromaticity elements were compared via a spectrophotometer across various heating conditions within the visible light spectrum. In general, the moisture reduction rate increased with rising temperature and time. Surface image comparisons revealed an expanded area of light reflection on the heat-treated dried laver sample due to surface roughening from shrinkage. No statistically significant differences in chromaticity values were observed in the measurements of brightness (L*), redness (a*), and yellowness (b*). Reflectance spectrum measurements in the visible light region confirmed high reflectance under red wavelength conditions. In particular, a significant increase in reflectance at 700 nm compared with untreated samples was noted. The correlation between the increase in 700 nm reflectance of dried laver samples and heating conditions ranged from 0.7471 to 0.7793, suggesting its potential use as an indicator for comparing color changes in dried laver based on heating conditions.

Gamut Mapping and Extension Method in the xy Chromaticity Diagram for Various Display Devices (다양한 디스플레이 장치를 위한 xy 색도도상에서의 색역 사상 및 확장 기법)

  • Cho Yang-Ho;Kwon Oh-Seol;Son Chang-Hwan;Park Tae-Yong;Ha Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.43 no.1 s.307
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    • pp.45-54
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    • 2006
  • This paper proposed color matching technique, including display characterization, chromatic adaptation model, and gamut mapping and extension, to generate consistent colors for the same input signal in each display device. It is necessary to characterize the relationship between input and output colors for display device, to apply chromatic adaptation model considering the difference of reference white, and to compensate for the gamut which display devices can represent for reproducing consistent colors on DTV display devices. In this paper, 9 channel-independent GOG model, which is improved from conventional 3 channel GOG(gain, offset gamma) model, is used to consider channel interaction and enhance the modeling accuracy. Then, the input images have to be adjusted to compensate for the limited gamut of each display device. We proposed the gamut mapping and extension method, preserving lightness and hue of an original image and enhancing the saturation of an original image in xy chromaticity diagram. Since the hmm visual system is more sensitive to lightness and hue, these values are maintained as the values of input signal, and the enhancement of saturation is changed to the ratio of input and output gamut. Also the xy chromaticity diagram is effective to reduce the complexity of establishing gamut boundary and the process of reproducing moving-pictures in DTV display devices. As a result, reproducing accurate colors can be implemented when the proposed method is applied to LCD and PDP display devices

A study on the method of OLED device's lifetime test (OLED 소자의 수명 평가법에 관한 연구)

  • Choi, Young-Tae;Cho, Jai-Rip
    • Journal of the Korea Safety Management & Science
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    • v.10 no.4
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    • pp.145-152
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    • 2008
  • According to the Korea Agency for Technology and Standards under the Commerce Ministry, OLED device's lifetime is defined 50% drop of luminance. OLED device is self-emitting operating device, that means it becomes different color between pixels under using environment. That's reason of the different luminance drop ratio & chromaticity coordinates shift ratio with time. The problem is there is not recovered after luminance drop and color shift. We can recognize the difference of color as image sticking. First we studied when human recognize the difference of color and second we apply the method of OLED device's lifetime test that's able to check different color between pixels.

Digital Watermarking on the Color coordinate (칼라 좌표계에서의 디지털 워크마킹)

  • Lee Chang-Soon;Jung Song-Ju
    • Journal of Korea Society of Industrial Information Systems
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    • v.10 no.2
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    • pp.102-108
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    • 2005
  • CIELAB coordinate is represented by one lightness component and two chromaticity components and similar to human visual system. Visual devices such as computer monitor display images using RGB coordinate. We propose a technique for inserting the watermark of visually recognizable mark into the middle frequency domain of image. RGB coordinate image is transformed into CIELAB coordinate, which include the characteristics of Human vision and then a* component is transformed into DFT(Discrete Fourier transform) transform.

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A study on the method of OLED device's lifetime test (OLED 소자의 수명 평가법에 관한 연구)

  • Choi, Young-Tae;Cho, Jai-Rip
    • Proceedings of the Safety Management and Science Conference
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    • 2008.11a
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    • pp.131-143
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    • 2008
  • According to the Korea Agency for Technology and Standards under the Commerce Ministry, OLED device's lifetime is defined 50% drop of luminance. OLED device is self-emitting operating device, that means it becomes different color between pixels under using environment. That's reason of the different luminance drop ratio & chromaticity coordinates shift ratio with time. The problem is there is not recovered after luminace drop and color shift. We can recognize the difference of color as image sticking. First we studied when human recognize the difference of color and second we apply the method of OLED device's lifetime test that's able to check different color between pixels

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Object Identification and Localization for Image Recognition (이미지 인식을 위한 객체 식별 및 지역화)

  • Lee, Yong-Hwan;Park, Je-Ho;Kim, Youngseop
    • Journal of the Semiconductor & Display Technology
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    • v.11 no.4
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    • pp.49-55
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    • 2012
  • This paper proposes an efficient method of object identification and localization for image recognition. The new proposed algorithm utilizes correlogram back-projection in the YCbCr chromaticity components to handle the problem of sub-region querying. Utilizing similar spatial color information enables users to detect and locate primary location and candidate regions accurately, without the need for additional information about the number of objects. Comparing this proposed algorithm to existing methods, experimental results show that improvement of 21% was observed. These results reveal that color correlogram is markedly more effective than color histogram for this task. Main contribution of this paper is that a different way of treating color spaces and a histogram measure, which involves information on spatial color, are applied in object localization. This approach opens up new opportunities for object detection for the use in the area of interactive image and 2-D based augmented reality.