• Title/Summary/Keyword: Color Calibration

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Procedural Geometry Calibration and Color Correction ToolKit for Multiple Cameras (절차적 멀티카메라 기하 및 색상 정보 보정 툴킷)

  • Kang, Hoonjong;Jo, Dongsik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.4
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    • pp.615-618
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    • 2021
  • Recently, 3D reconstruction of real objects with multi-cameras has been widely used for many services such as VR/AR, motion capture, and plenoptic video generation. For accurate 3D reconstruction, geometry and color matching between multiple cameras will be needed. However, previous calibration and correction methods for geometry (internal and external parameters) and color (intensity) correction is difficult for non-majors to perform manually. In this paper, we propose a toolkit with procedural geometry calibration and color correction among cameras with different positions and types. Our toolkit consists of an easy user interface and turned out to be effective in setting up multi-cameras for reconstruction.

A New Liquid Crystal Color Calibration Technique Using Neural Networks and Median Filtering

  • Lee, Dae-Hee;Chung, Jae-Hun;Won, Se-Youl;Kim, Yun-Taek;Boo, Kwang-Suk
    • Journal of Mechanical Science and Technology
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    • v.14 no.1
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    • pp.113-120
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    • 2000
  • This study has developed a new liquid crystal calibration technique using Neural networks with median filtering and applied this technique to heat transfer measurements. To verify the validity of this new measurement technique, the local Nusselt numbers on a flat plate surface subjected to an axisymmetric impinging jet were measured and compared with the results by the conventional Hue-temperature calibration technique under the same conditions. Because the Neural networks predict the non-linear relations between temperatures and corresponding R, G, B values, Neural networks-median filtering calibration technique can utilize a much wider color band in the experiment than the Hue-temperature calibration technique, resulting in a significant reduction in the experimental time.

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A Composite Camera Calibration Technique for Thermal Deterioration Diagnosis of Power Distribution Line (배전 선로의 열화 진단을 위한 복합 카메라 보정기법)

  • Jung, Ha-Hyoung;Park, Jin-ha;Lyou, Joon
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.6
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    • pp.463-469
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    • 2016
  • This paper presents a composite camera calibration method to determine thermal degradation of power distribution equipment by combining an infrared (IR) camera and a color camera. A calibration jig was first constructed to match the properties of the two cameras. Our calibration and visualization techniques allow for the display of two images, one from the color camera and the other from the IR camera with different field of views (FOVs), on the screen at the same time. To confirm its validity, several case studies have been developed to analyze thermal deterioration limits of indoor and outdoor power distribution facilities.

OSMI ocean color products with updated cross-calibration coefficients

  • Lee S. G.;Kim Y. S.
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.494-497
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    • 2004
  • To date the KOMPSAT OSMI(Ocean Scanning Multi-spectral Imager) data have been widely used in natural disaster monitoring such as Typhoon, Asian Dust, Red Tide, and Forest Fire. Quantitative analyses related to the marine ecosystem have been delayed because they require good quality of data through Cal/Val activities. To resolve such problem, KARI performed the OSMI crosscalibration study with SeaWiFS team. In this study, we will demonstrate the OSMI ocean color products with updated cross-calibration coefficients and compare them to the previous cross-calibration results.

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Determination of Leaf Color and Health State of Lettuce using Machine Vision (기계시각을 이용한 상추의 엽색 및 건강상태 판정)

  • Lee, J.W.
    • Journal of Biosystems Engineering
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    • v.32 no.4
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    • pp.256-262
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    • 2007
  • Image processing systems have been used to measure the plant parameters such as size, shape and structure of plants. There are yet some limited applications for evaluating plant colors due to illumination conditions. This study was focused to present adaptive methods to analyze plant leaf color regardless of illumination conditions. Color patches attached on the calibration bars were selected to represent leaf colors of lettuces and to test a possibility of health monitoring of lettuces. Repeatability of assigning leaf colors to color patches was investigated by two-tailed t-test for paired comparison. It resulted that there were no differences of assignment histogram between two images of one lettuce that were acquired at different light conditions. It supported that use of the calibration bars proposed for leaf color analysis provided color constancy, which was one of the most important issues in a video color analysis. A health discrimination equation was developed to classify lettuces into one of two classes, SOUND group and POOR group, using the machine vision. The classification accuracy of the developed health discrimination equation was 80.8%, compared to farmers' decision. This study could provide a feasible method to develop a standard color chart for evaluating leaf colors of plants and plant health monitoring system using the machine vision.

CMAC Neuro-Fuzzy Design for Color Calibration (컬러재현을 위한 CMAC의 뉴로퍼지 설계)

  • 이철희;변오성;문성룡;임기영
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.4
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    • pp.331-335
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    • 2001
  • Cl\iAC model was proposed by Albus [6J to formulate the processing characteristics of the human cerebellum. Instead of the global weight updating scheme used in the back propagation, CMAC use the local weight updating scheme. Therefore, CMAC have the advantage of fast learning and high convergence rate. In this paper, simulate Color Calibration by CMAC in color images and design hardware by VHDL-base high-level synthesis.

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Study on CMS Application in Hybrid UV Waterless Off-Set Printing (H-UV 무습수 오프셋 인쇄에서 CMS 적용에 관한 연구)

  • Koo, Chul-Whoi;Cho, Ga-Ram
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.45 no.5
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    • pp.1-13
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    • 2013
  • This study found fit optimum C, M, Y, K solid density and $CIEL^*a^*b^*$ value to paper & ink as well as check about printing machine state for color management in H-UV waterless off-set printing first. These values applied to GRACoL G7 calibration method. This method is one of color standard management method of printing. GRACoL G7 calibration method is possible stable tone reappearance by controlling gray balance by NPDC(Natural Printing Density Curve). Also, this study used values to make device profile as result that is gotten by application of GRACoL G7 calibration method. This profile was applied to CMS(Color Management System) of H-UV waterless off-set printing, and the result was possible by color management that correspond in printing quality standard of ISO 12647-2 and GRACol 2006 specifications.

Effect of Grinding on Color and Chemical Composition of Pork Sausages by Near Infrared Spectrophotometric Analyses

  • Kang, J.O.;Park, J.Y.;Choy, Y.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.6
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    • pp.858-861
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    • 2001
  • Near Infrared spectroscopy was applied to the samples of processed pork to see the effect of grinding on chemical components analyses. Data from conventional chemical analyses of moisture, fat, protein, NaCl were put into calibration model by NIR of reflectance mode. The other properties observed were pH and color parameters ($L^*,\;a^*,\;b^*$). Spectral ranges of 400~2500 nm and 400~1100 nm were compared for color parameters. Spectral ranges of 400~2500 nm and 1100~2500 nm were compared for chemical components and pH. Different spectral ranges caused little changes in the coefficients of determination or standard errors. $R^{2,}s$ of calibration models for color parameters were in the range of 0.97 to 1.00. $R^{2,}s$ of calibration models of intact sausages for moisture, protein, fat, NaCl and pH were 0.98, 0.89, 0.95, 0.73 and 0.77, respectively using spectra at 1100~2500 nm. $R^{2,}s$ of calibration models of ground sausages for moisture, protein, fat, NaCl and pH were 0.97, 0.91, 0.97, 0.42 and 0.56, respectively using spectra at 1100~2500 nm.

ERROR ANALYSIS FOR GOCI RADIOMETRIC CALIBRATION

  • Kang, Gm-Sil;Youn, Heong-Sik
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.187-190
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    • 2007
  • The Geostationary Ocean Color Imager (GOCI) is under development to provide a monitoring of ocean-color around the Korean Peninsula from geostationary platforms. It is planned to be loaded on Communication, Ocean, and Meteorological Satellite (COMS) of Korea. The GOCI has been designed to provide multi-spectral data to detect, monitor, quantify, and predict short term changes of coastal ocean environment for marine science research and application purpose. The target area of GOCI observation covers sea area around the Korean Peninsula. Based on the nonlinear radiometric model, the GOCI calibration method has been derived. The nonlinear radiometric model for GOCI will be validated through ground test. The GOCI radiometric calibration is based on on-board calibration devices; solar diffuser, DAMD (Diffuser Aging Monitoring Device). In this paper, the GOCI radiometric error propagation is analyzed. The radiometric model error due to the dark current nonlinearity is analyzed as a systematic error. Also the offset correction error due to gain/offset instability is considered. The radiometric accuracy depends mainly on the ground characterization accuracies of solar diffuser and DAMD.

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Examination of Cross-calibration Between OSMI and SeaWiFS: Comparison of Ocean Color Products

  • Lee, Sun-Gu;Kim, Yong-Seung
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.209-215
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    • 2002
  • Much effort has been made in the radiometric calibration of the ocean scanning multispectral imager (OSMI) since after the successful launch of KOMPSAT-1 in 1999. A series of calibration coefficients for OSMI detectors were obtained in collaboration with the NASA Sensor Intercomparison and Merger for Biological and Interdisciplinary (SIMBIOS) project office. In this study, we compare the OSMI level-2 products (e.g., chlorophyll-a concentration) calculated from the NASA cross-calibration coefficients with the SeaWiFS counterparts. Sample study areas are some of diagonostic data sites recommended by the SIMBIOS working group. We will present the preliminary results of this comparative study.

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