• Title/Summary/Keyword: color compensation

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Controlling Brightness Compensation of Full Color LED Vision (천연색 LED 정보표시 시스템의 휘도보정 제어장치)

  • Hwang, Hyun-Hwa;Yim, Hyung-Kun;Park, Jung-Hwan;Lee, Jong-Ha
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.1291-1296
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    • 2005
  • In this paper, we prevent a display quality drop for image of characteristics brightness ununiformity depend on LED use to LED vision. It is about that method also a control system development equipped with brightness compensation function of LED vision which is done easily for LED set up of LED vision. Generally, It is calculate driving current value is attended by each brightness to brightness characteristics mathematical function establish by "Y=aX+b", When is doing brightness value for "Y", driving current value for "X", brightness compensation value by using time for "b", characteristics value for "a" ground with characteristics curve of LED. So much, First It is create brightness data of each pixel take a photograph red, green and blue of LED vision. Second It is get average error about each pixel which get average brightness value of entire. Last, It is handle a complicated for about gradationally regulation to color and brightness of image send to LED vision. Also It raise the whole average brightness value of vision adjust for "b" value to solve brightness drop problem of LED using the long time.

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A Development of a Portable Color Scanner Using Photo Sensors for Full-Color LED Illumination Control (LED 조명 제어를 위한 컬러센서 기반 포터블 스캐너 개발)

  • Chun, Sung-Yong;Lee, Chan-Su
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.11
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    • pp.14-25
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    • 2011
  • Full-Color LED lighting system requires efficient control of the lighting color in order to easily achieve various color effects. In this paper, we present not only a portable color scanner using color sensors which can control lighting color directly from detected color but also methods to convert detected color to a complementary color, similar colors and so on. In addition, we propose a compensation method for measured sensor color to reduce measurement errors more than 50[%] in detected color. The developed color scanner is applied to control full-color LED ceiling light for emotional lighting.

A New Illumination Compensation Method based on Color Optimization Function for Generating 3D Volumetric Model (3차원 체적 모델의 생성을 위한 색상 최적화 함수 기반의 조명 보상 기법)

  • Park, Byung-Seo;Kim, Kyung-Jin;Kim, Dong-Wook;Seo, Young-Ho
    • Journal of Broadcast Engineering
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    • v.25 no.4
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    • pp.598-608
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    • 2020
  • In this paper, we propose a color correction technique for images acquired through a multi-view camera system for acquiring a 3D model. It is assumed that the 3D volume is captured indoors, and the position and intensity of the light is constant over time. 8 multi-view cameras are used, and converging toward the center of the space, so even if the lighting is constant, the intensity and angle of light entering each camera may be different. Therefore, a color optimization function is applied to a color correction chart taken from all cameras, and a color conversion matrix defining a relationship between the obtained 8 images is calculated. Using this, the images of all cameras are corrected based on the standard color correction chart. This paper proposed a color correction method to minimize the color difference between cameras when acquiring an image using 8 cameras of 3D objects, and experimentally proved that the color difference between images is reduced when it is restored to a 3D image.

Thermal Kinetics of Color Changes of Purple Sweet Potato Anthocyanin Pigment (자색고구마 Anthocyanin 색소의 가열에 대한 속도론적 연구)

  • Lee, Lan-Sook;Rhim, Jong-Whan
    • Korean Journal of Food Science and Technology
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    • v.29 no.3
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    • pp.497-501
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    • 1997
  • Kinetic parameters on heat-induced color changes of anthocyanin pigment from purple sweet potato were determined in the temperature range of $121{\sim}141^{\circ}C$. Color change determined by a browning index $(A_{532}\;nm/A_{420}\;nm)$ followed second order reaction kinetics. Activation energy values of purple sweet potato pigment solutions of pH 2.0, 3.0, 4.0 and 5.0 were 69.57, 76.68, 81.07 and 92.98 kJ/mol, respectively, indicating that temperature dependency of the reaction increased with pH. Apparent kinetic compensation effect between preex-ponential factor and activation energy value was observed.

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Improvement of Color Reproduction Using Gamma and CCT Correction on Small LCD Display for Mobile Phone (휴대폰용 소형 LCD 디스플레이에서 감마 및 상관 색온도 보정을 이용한 색재현 성능 향상)

  • Han Chan-Ho;Sohng Kyu-Ik;Kwon Seong-Geun
    • Journal of Korea Multimedia Society
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    • v.9 no.4
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    • pp.451-459
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    • 2006
  • Color reproduction of small LCD display is quite different from that of standard CRT due to the difference of physical, electrical, and optical characteristics. In this paper, we propose a simple and practical method using gamma and CCT correction for improvement of color reproduction on a small LCD display. First, we investigate characteristics of a small LCD display such as brightness, uniformity, color temperature, white and black balance, and nonlinear gamma. And, we also analyze color reproduction region and CCT trajectory according to LCD's input levels. Finally, the optimum gamma and CCT compensation method using LUT is proposed, and our proposed method was realized at mobile phone without hardware modification. In the experimental results, the result image of proposed algorithm is more close to standard color.

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A Studyt on the soft-proofing method on Monitor using characteristics of printing device (출력장치의 인쇄특성을 고려한 모니텅상의 컬러교정)

  • 송경철;강상훈
    • Proceedings of the Korean Printing Society Conference
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    • 2000.04a
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    • pp.45-55
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    • 2000
  • Recently, as the prepress mainstream is changed to the digital wolkflow, various digital proofing systems such as high price dye sublimation printers and low price ink jet printers are widely used in printing industry. Generally, CRT monitors are also often used as a soft proofing device for hard-copy image output. However, displayed color image on CRT monitor does not match to the actual color printing sheets. Because, the color space of CRT monitor used RGB color space, and it is differ with printing device color space, CMY. Therefore, proper color compensations are needed to match the colors between hard-copy proofs on the printing device and soft copy proofs on the monitor. For the proper compensation, we used LUT and gamut mapping method for color space transformation between device dependent color space and device independent color space, vis a vis. This paper shows the application method and the usefulness of CRT monitor for the soft-copy proofing using the output characteristics of printing device.

The Compensation of Chromaticity Coordinates on Primary Color Reaction of Urine Strips (요분석 스트립의 정색반응에 대한 색도좌표 보정)

  • Kim, Jae-Hyung;Joo, Jin-Wook;Nam, Sang-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.320-323
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    • 2001
  • A computer simulation was performed to distinguish quantitatively a color reaction in a urine analysis systems by using the spectral power distribution of LEDs. the spectral reflectance of a urine strip. and the spectral sensitivity of photodiode. The CIE tristimulus values and CIE chromaticity coordinates ware modified to be conformable with real color reactions in a urine strips. Results on color simulation showed a of real color in comparison with those obtained by Colorimeter CM2C(Color Savvy).

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Visible and NIR Image Synthesis Using Laplacian Pyramid and Principal Component Analysis (라플라시안 피라미드와 주성분 분석을 이용한 가시광과 적외선 영상 합성)

  • Son, Dong-Min;Kwon, Hyuk-Ju;Lee, Sung-Hak
    • Journal of Sensor Science and Technology
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    • v.29 no.2
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    • pp.133-140
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    • 2020
  • This study proposes a method of blending visible and near infrared images to enhance edge details and local contrast. The proposed method consists of radiance map generation and color compensation. The radiance map is produced by a Laplacian pyramid and a soft mixing method based on principal component analysis. The color compensation method uses the ratio between the composed radiance map and the luminance channel of a visible image to preserve the visible image chrominance. The proposed method has better edge details compared to a conventional visible and NIR image blending method.

Robust Face Detection Using Illumination-Compensation and Morphological Processing

  • Yun, Jae-Ung;Lee, Hyung-Jin;Paul, Anjan Kumar;Baek, Joong-Hwan
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.329-330
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    • 2007
  • This paper presents a simple and robust face detection algorithm that can be utilized to video summary. We firstly apply the Illumination-compensation process for reducing the effect of brightness on the image. And then, we analyze the face region based on color in the YCbCr space to obtain the skin color. Also, we try the morphological image processing called closing algorithm to improve the detection. Experimental results demonstrate the effectiveness of our face detection algorithm that leads to 96.7 % precision ratio on average.

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Face Detection based on Pupil Color Distribution Maps with the Frequency under the Illumination Variance (빈도수를 고려한 눈동자색 분포맵에 기반한 조명 변화에 강건한 얼굴 검출 방법)

  • Cho, Han-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.5
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    • pp.225-232
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    • 2009
  • In this paper, a new face detection method based on pupil color distribution maps with the frequency under the illumination variance is proposed. Face-like regions are first extracted by applying skin color distribution maps to a color image and then, they are reduced by using the standard deviation of chrominance components. In order to search for eye candidates effectively, the proposed method extracts eye-like regions from face-like regions by using pupil color distribution maps. Furthermore, the proposed method is able to detect eyes very well by segmenting the eye-like regions, based on a lighting compensation technique and a segmentation algorithm even though face regions are changed into dark-tone due to varying illumination conditions. Eye candidates are then detected by means of template matching method. Finally, face regions are detected by using the evaluation values of two eye candidates and a mouth. Experimental results show that the proposed method can achieve a high performance.

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