• Title/Summary/Keyword: Color Calibration

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Characteristics of Ocean Scanning Multi-spectral Imager (OSMI)

  • Cho, Young-Min;Yong, Sang-Soon;Woo, Sun-Hee;Lee, Sang-Gyu;Oh, Kyoung-Hwan;Paik, Hong-Yul
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.319-324
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    • 1998
  • Ocean Scanning Multispectral Imager (OSMI) is a payload on the Korean Multi-purpose SATellite (KOMPSAT) to perform worldwide ocean color monitoring for the study of biological oceanography. The instrument images the ocean surface using a whisk-broom motion with a swath width of 800 km and a ground sample distance (GSD) of < 1 km over the entire field-of-view (FOV). The instrument is designed to have an on-orbit operation duty cycle of 20% over the mission lifetime of 3 years with the functions of programmable gain/offset and on-board image data storage. The instrument also performs sun calibration and dark calibration for on-board instrument calibration. The OSMI instrument is a multi-spectral imager covering the spectral range from 400 nm to 900 nm using a CCD Focal Plane Array (FPA). The ocean colors are monitored using 6 spectral channels that can be selected via ground commands after launch. The instrument performances are fully measured for 8 basic spectral bands centered at 412nm, 443nm, 490nm, 510nm, 555nm, 670nm, 765nm and 865nm during ground characterization of instrument. In addition to the ground calibration, the on-board calibration will also be used for the on-orbit band selection. The on-orbit band selection capability can provide great flexibility in ocean color monitoring.

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Standard calibration for H-α filter of DOAO 1m telescope

  • Ahn, Hojae;Pak, Soojong;Kang, Wonseok;Kim, Taewoo;Shim, Hyunjin
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.89.1-89.1
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    • 2017
  • In this poster, we present standard calibration processes and results for photometry of $H-{\alpha}$ filter using broadband filters. We took data from a night in stable weather condition. And we derived parameters for band pass calibration including color terms. The corrected photometry results from broadband filters like V and R filters showed high correlation enough to replace instrumental $H-{\alpha}$ magnitude. We plan to extend these standardizing processes to another narrowband filters and flux calibration of narrowband filters from photometry of PNe.

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Color and Brightness Calibration Convergence Technology for 5D Virtual Reality Attractions (5D 가상현실 어트랙션을 위한 색상 및 밝기 보정 융합 기술)

  • Han, Jung-Soo
    • Journal of the Korea Convergence Society
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    • v.7 no.1
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    • pp.25-30
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    • 2016
  • Virtual reality items are increased take-all type of markets like Universal, such as the United States as a leader in the virtual reality technology. Multi-user have to get direct experiences with the whole body like visual, tactile, hearing, sense of movement, and it must be developed new forms of content platform to enjoy immerse deeply into the content. Visitors are not to enjoy the content passively but rather to enjoy the content actively. So it like that should develope content to maximize the immersion. It need the development of new forms of mixed 5D virtual reality Attraction content with all of factors like $360^{\circ}$ circle vision, stereoscopic images, interaction, simulator, and the environmental effect. We proposes how to make the color and brightness calibration technology for this purpose.

TheReviser : A Gesture-based Editing System on a Digital Desk (TheReviser : 가상 데스크 상의 제스처 기반 문서 교정 시스템)

  • Jung, Ki-Chul;Kang, Hyun
    • The KIPS Transactions:PartB
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    • v.11B no.4
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    • pp.527-536
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    • 2004
  • TheReviser is a digital document revision application on a projection display, which allows us to interact a digital document with the same gestures used for paper documents revision. To enable these interactions, TheReviser should detect foreground objects such as hands or pens on a projection display, and should spot and recognize gesture commands from continuous movements of a user. To detect foreground objects from a complex background in various lighting conditions, we perform geometry and color calibration between a captured image and a frame buffer image. TheReviser uses an HMM-based gesture recognition method Experimental results show that the proposed application recognizes user's gestures on average 93.22% in test gesture sequences.

Calibration of Scanner at Color Inspection of printed Texture (직물의 색상검사에서 스캐너의 편차 보정)

  • 정병묵;조지승;박무진
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.383-386
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    • 2002
  • It is very important to inspect color of printed texture in the textile process. To distinguish the color of the printed texture, RGB color values obtained from a scanner must be transformed to the standard colorimetric system used in the textile industry. It is XYZ color system that is defined by CIE(Commission Internationale do 1Eclairage). The mapping from RGB to XYZ color values is not simple and the scanner has even a positional deviation of RGB colors. In this paper an automatic color inspection method using a general scanning machine is presented. We used a U(neural network) model to map RGB to XYZ and compensate the positional error. In the real experiments, this inspection system shows to get very exact XYZ values from the traditional scanner regardless of the measuring position.

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Improvement of Calibration Method of Thermochromic Liquid Crystal Reflecting Measurement Angle (측정각도를 고려한 액정교정기법의 개선)

  • Yoon, Soon-Hyun;Sim, Jae-Kyung;Woo, Chang-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.2
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    • pp.188-194
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    • 2000
  • Thermochromic liquid crystal reflect a unique color at even temperature. Therefore, they have been successfully applied to non-intrusive heat transfer research. Hue capturing method is widely used in the quantitative measurement from the TLC image. However it is affected by several measurement conditions. The distances of camera and light source have little influence on the color, but the value of hue is seriously affected by the measurement angle. In this study, the hue capturing method is improved by considering the effect of measurement angle. This improved calibration method can diminish the misreading of temperature caused by curvature of test surface.

A Study on Color Management of Input and Output Device in Electronic Publishing (II) (전자출판에서 입.출력 장치의 컬러 관리에 관한 연구 (II))

  • Cho, Ga-Ram;Koo, Chul-Whoi
    • Journal of the Korean Graphic Arts Communication Society
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    • v.25 no.1
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    • pp.65-80
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    • 2007
  • The input and output device requires precise color representation and CMS (Color Management System) because of the increasing number of ways to apply the digital image into electronic publishing. However, there are slight differences in the device dependent color signal among the input and output devices. Also, because of the non-linear conversion of the input signal value to the output signal value, there are color differences between the original copy and the output copy. It seems necessary for device-dependent color information values to change into device-independent color information values. When creating an original copy through electronic publishing, there should be color management with the input and output devices. From the devices' three phases of calibration, characterization and color conversion, the device-dependent color should undergo a color transformation into a device-independent color. In this paper, an experiment was done where the input device used the linear multiple regression and the sRGB color space to perform a color transformation. The output device used the GOG, GOGO and sRGB for the color transformation. After undergoing a color transformation in the input and output devices, the best results were created when the original target underwent a color transformation by the scanner and digital camera input device by the linear multiple regression, and the LCD output device underwent a color transformation by the GOG model.

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COLOR EXCESSES AND PERIOD-COLOR RELATION OF CLASSICAL CEPHEIDS

  • Kim, Chul-Hee;Moon, B.K.;Yushchenko, A.V.
    • Journal of The Korean Astronomical Society
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    • v.43 no.5
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    • pp.153-159
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    • 2010
  • Color excesses of classical Cepheids in the uvby color system are estimated for the calibration stars with distances from the literature that are measured independently. Intrinsic photometric indices for these stars are calculated and a calibrated empirical relation between (b - y)$_0$, period, [$c_1$], and [$m_1$] is derived through a linear fit. This relation is used to determine color excesses E(b-y) for 59 Cepheids. We also examine the period-color [log P : (b - y)$_0$] relation, and find no signs of nonlinearity. We estimate the effective temperature and surface gravity of several Cepheids using both Kurucz and MARCS/SSG grids for [Fe=H]=0.0. We confirm that both temperature and surface gravity are higher, by about 150K and 0.4 respectively, when the MARCS/SSG atmospheric grids are used.

Extraction of Geometric and Color Features in the Tobacco-leaf by Computer Vision (컴퓨터 시각에 의한 잎담배의 외형 및 색 특징 추출)

  • Cho, H.K.;Song, H.K.
    • Journal of Biosystems Engineering
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    • v.19 no.4
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    • pp.380-396
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    • 1994
  • A personal computer based color machine vision system with video camera and fluorescent lighting system was used to generate images of stationary tobacco leaves. Image processing algorithms were developed to extract both the geometric and the color features of tobacco leaves. Geometric features include area, perimeter, centroid, roundness and complex ratio. Color calibration scheme was developed to convert measured pixel values to the standard color unit using both statistics and artificial neural network algorithm. Improved back propagation algorithm showed less sum of square errors than multiple linear regression. Color features provide not only quality evaluation quantities but the accurate color measurement. Those quality features would be useful in grading tobacco automatically. This system would also be useful in measuring visual features of other agricultural products.

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Rapid Measure of Color and Catechins Contents in Processed Teas Using NIRS (근적외선 분광광도계를 이용한 차 제품의 색상 및 카테킨류의 신속 측정)

  • Chun, Jong-Un
    • Korean Journal of Plant Resources
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    • v.23 no.4
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    • pp.386-392
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    • 2010
  • This study was done to measure the color and catechins contents in processed teas using the whole bands (400~2500 nm) with near-infrared spectroscopy(NIRS). The powder colors of 109 processed teas were measured with a colorimeter. The a/b ratios in Hunter color scale in processed teas accounted for about 98.9% of the variation in the fermentation degree(FD), indicating that the a/b ratio was a very useful trait for assessing fermentation degree. Also tea powders were scanned in the visible bands used with NIRSystem. The calibration equations for powder colors were developed using the regression method of modified partial least squares(MPLS) with the internal cross validation. The equations had low SECV (standard errors of cross-validation), and high $R^2$ (coefficient of determination in calibration) values with 0.996~1.00, indicating that the visible bands(400~700 nm) with NIRS could be used to rapidly measure the variables related to powder color and fermentation degree. Also another powders of 137 processed teas were scanned at 780~2500 nm bands in the reflectance mode. The calibration equations were developed using the regression method of MPLS with the internal cross validation. The equations had low SECV, and high $R^2$ (0.896~0.983) values, showing that NIRS could be used to rapidly discriminate the contents of EGC($R^2$=0.919), EC(0.896), EGCg(0.978), ECg(0.905) and total catechins(0.983) in processed teas with high precision and ease.