• Title/Summary/Keyword: reflectance model

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A study on the transfromation from CMYK to Labcolor space using color reproduction models (색재현 모델을 이용한 CMYK to Lab 색변환에 관한 연구)

  • 차재영;구철회
    • Proceedings of the Korean Printing Society Conference
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    • 2000.04a
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    • pp.25-34
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    • 2000
  • Recently, color proofing in printing industry grow rapidly. If an order decide color from known color information in the case of color reproduction, we can reduce expenses and time. In color proofing the best important point must be closed proofed color to primary color and secondary color. Model-based approaches have the advantages of faster recharacterization and the opportunity of simulating product enhancements such as changes in ink properties and halftoning. In this paper, we transformed the dot area of CMYK to CIELAB color space using color reprodution models. Firstly, we measured spectral reflectance of primary color printed by Matchprint II and the data was used to find tone reproduction curve using regression equation, and than we applied at primary color model, such as Murray-Davies, Yule-Nilsen, and mixed color model, such as Kubelka--Munk, relaxed version of spectral Neugebauser. In such results, the Kubleka-Munk model resulted in the best spectral reconstruction accuracy followed by relaxed version of spectral Neugebauer model, color difference is 2.8401.

A study on the Transformation from CMYK to $L^{*}a^{*}b^{*}$ color space using color reproduction models (색재현 모델을 이용한 CMYK에서 $L^{*}a^{*}b^{*}$ 색변환에 관한 연구)

  • 차재영;조가람;구철희
    • Journal of the Korean Graphic Arts Communication Society
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    • v.18 no.2
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    • pp.29-40
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    • 2000
  • Recently. color proofing in printing industry grow rapidly. If an order decide color from known color information in the case of color reproduction, we can reduce expenses and time. In color proofing the best important point must be closed proofed color to primary color and secondary color. Model-based approaches have the advantages of faster recharacterization and the opportunity of simulating product enhancements such as changes in ink properties and halftoning. In this paper, we transformed the dot area of CMYK to CIELAB color space using color reproduction models. Firstly, we measured spectral reflectance of primary color printed by Matchprint II and the data was used to find tone reproduction curve using regression equation, and than we applied at primary color model, such as Murray-Davies, Yule-Nilsen, and mixed color model, such as Kubelka-Munk, relaxed version of spectral Neugebauer. In such results, the Kubelka-Munk model resulted in the best spectral reconstruction accuracy followed by relaxed version of spectral Neugebauer model, color difference is 2.8401.

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ATC: An Image-based Atmospheric Correction Software in MATLAB and SML

  • Choi, Jae-Won;Won, Joong-Sun;Lee, Sa-Ro
    • Korean Journal of Remote Sensing
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    • v.24 no.5
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    • pp.417-425
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    • 2008
  • An image-based atmospheric correction software ATC is implemented using MATLAB and SML (Spatial Modeler Language in ERDAS IMAGINE), and it was tested using Landsat TM/ETM+ data. This ATC has two main functional modules, which are composed of a semiautomatic type and an automatic type. The semi-automatic functional module includes the Julian day (JD), Earth-Sun distance (ESD), solar zenith angle (SZA) and path radiance (PR), which are programmed as individual small functions. For the automatic functional module, these parameters are computed by using the header file of Landsat TM/ETM+. Three atmospheric correction algorithms are included: The apparent reflectance model (AR), one-percent dark object subtraction technique (DOS), and cosine approximation model (COST). The ACT is efficient as well as easy to use in a system with MATLAB and SML.

Evaluation of Phase Transition Behavior of Ge2Sb2Te5 Thin Film for Phase Change Random Access Memory (상변환 메모리의 응용을 위한 Ge2Sb2Te5 박막의 상변환 거동 평가)

  • Do, Woo-Hyuk;Kim, Sung-Soon;Bae, Jun-Hyun;Cha, Jun-Ho;Kim, Kyung-Ho;Lee, Young-Kook;Lee, Hong-Lim
    • Journal of the Korean Ceramic Society
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    • v.44 no.1 s.296
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    • pp.18-22
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    • 2007
  • The phase transition behavior of $Ge_2Sb_2Te_5$ (GST) thin film, which is a candidate material of recording layer for phase change random access memory (PRAM), has been evaluated using an in-situ reflectance measurement method. The experimental data have been analyzed by using johnson-mehl-avrami-kolomogorov (JMAK) model. JMAK model can be used only in isothermal state. However, temperature changes with time during the operation of PRAM. To apply JMAK equation to PRAM simulation, it has been assumed that the temperature increases stepwise and isothermally. By using JMAK equation and assumption for the transient state, the phase transition behavior of GST thin film has been predicted under $3^{\circ}C/min$ heating rate in this study. The simulation result agrees well with the experimental results. Therefore, It can be concluded that JMAK equation can be used far the PRAM simulation model.

Prediction of Heavy Metal Content in Compost Using Near-infrared Reflectance Spectroscopy

  • Ko, H.J.;Choi, H.L.;Park, H.S.;Lee, H.W.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.12
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    • pp.1736-1740
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    • 2004
  • Since the application of relatively high levels of heavy metals in the compost poses a potential hazard to plants and animals, the content of heavy metals in the compost with animal manure is important to know if it is as a fertilizer. Measurement of heavy metals content in the compost by chemical methods usually requires numerous reagents, skilled labor and expensive analytical equipment. The objective of this study, therefore, was to explore the application of near-infrared reflectance spectroscopy (NIRS), a nondestructive, cost-effective and rapid method, for the prediction of heavy metals contents in compost. One hundred and seventy two diverse compost samples were collected from forty-seven compost facilities located along the Han river in Korea, and were analyzed for Cr, As, Cd, Cu, Zn and Pb levels using inductively coupled plasma spectrometry. The samples were scanned using a Foss NIRSystem Model 6500 scanning monochromator from 400 to 2,500 nm at 2 nm intervals. The modified partial least squares (MPLS), the partial least squares (PLS) and the principal component regression (PCR) analysis were applied to develop the most reliable calibration model, between the NIR spectral data and the sample sets for calibration. The best fit calibration model for measurement of heavy metals content in compost, MPLS, was used to validate calibration equations with a similar sample set (n=30). Coefficient of simple correlation (r) and standard error of prediction (SEP) were Cr (0.82, 3.13 ppm), As (0.71, 3.74 ppm), Cd (0.76, 0.26 ppm), Cu (0.88, 26.47 ppm), Zn (0.84, 52.84 ppm) and Pb (0.60, 2.85 ppm), respectively. This study showed that NIRS is a feasible analytical method for prediction of heavy metals contents in compost.

The evaluation of Spectral Vegetation Indices for Classification of Nutritional Deficiency in Rice Using Machine Learning Method

  • Jaekyeong Baek;Wan-Gyu Sang;Dongwon Kwon;Sungyul Chanag;Hyeojin Bak;Ho-young Ban;Jung-Il Cho
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.88-88
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    • 2022
  • Detection of stress responses in crops is important to diagnose crop growth and evaluate yield. Also, the multi-spectral sensor is effectively known to evaluate stress caused by nutrient and moisture in crops or biological agents such as weeds or diseases. Therefore, in this experiment, multispectral images were taken by an unmanned aerial vehicle(UAV) under field condition. The experiment was conducted in the long-term fertilizer field in the National Institute of Crop Science, and experiment area was divided into different status of NPK(Control, N-deficiency, P-deficiency, K-deficiency, Non-fertilizer). Total 11 vegetation indices were created with RGB and NIR reflectance values using python. Variations in nutrient content in plants affect the amount of light reflected or absorbed for each wavelength band. Therefore, the objective of this experiment was to evaluate vegetation indices derived from multispectral reflectance data as input into machine learning algorithm for the classification of nutritional deficiency in rice. RandomForest model was used as a representative ensemble model, and parameters were adjusted through hyperparameter tuning such as RandomSearchCV. As a result, training accuracy was 0.95 and test accuracy was 0.80, and IPCA, NDRE, and EVI were included in the top three indices for feature importance. Also, precision, recall, and f1-score, which are indicators for evaluating the performance of the classification model, showed a distribution of 0.7-0.9 for each class.

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Prediction from Linear Regression Equation for Nitrogen Content Measurement in Bentgrasses leaves Using Near Infrared Reflectance Spectroscopy (근적외선 분광분석기를 이용한 잔디 생체잎의 질소 함량 측정을 위한 검량식 개발)

  • Cha, Jung-Hoon;Kim, Kyung-Duck;Park, Dae-Sup
    • Asian Journal of Turfgrass Science
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    • v.23 no.1
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    • pp.77-90
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    • 2009
  • Near Infrared Reflectance Spectroscopy(NIRS) is a quick, accurate, and non-destructive method to measure multiple nutrient components in plant leaves. This study was to acquire a liner regression equation by evaluating the nutrient contents of 'CY2' creeping bentgrass rapidly and accurately using NIRS. In particular, nitrogen fertility is a primary element to keep maintaining good quality of turfgrass. Nitrogen, moisture, carbohydrate, and starch were assessed and analyzed from 'CY2' creeping bentgrass clippings. A linear regression equation was obtained from accessing NIRS values from NIR spectrophotometer(NIR system, Model XDS, XM-1100 series, FOSS, Sweden) programmed with WinISI III project manager v1.50e and ISIscan(R) (Infrasoft International) and calibrated with laboratory values via chemical analysis from an authorized institute. The equation was formulated as MPLS(modified partial least squares) analyzing laboratory values and mathematically pre-treated spectra. The accuracy of the acquired equation was confirmed with SEP(standard error of prediction), which indicated as correlation coefficient($r^2$) and prediction error of sample unacquainted, followed by the verification of model equation of real values and these monitoring results. As results of monitoring, $r^2$ of nitrogen, moisture, and carbohydrate in 'CY2' creeping bentgrass was 0.840, 0.904, and 0.944, respectively. SEP was 0.066, 1.868, and 0.601, respectively. After outlier treatment, $r^2$ was 0.892, 0.925, and 0.971, while SEP was 0.052, 1.577, and 0.394, respectively, which totally showed a high correlation. However, $r^2$ of starch was 0.464, which appeared a low correlation. Thereof, the verified equation appearing higher $r^2$ of nitrogen, moisture, and carbohydrate showed its higher accuracy of prediction model, which finally could be put into practical use for turf management system.

A Study on Application of Illumination Models for Color Constancy of Objects (객체의 색상 항등성을 위한 조명 모델 응용에 관한 연구)

  • Park, Changmin
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.13 no.1
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    • pp.125-133
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    • 2017
  • Color in an image is determined by illuminant and surface reflectance. So, to recover unique color of object, estimation of exact illuminant is needed. In this study, the illumination models suggested to get the object color constancy with the physical illumination model based on physical phenomena. Their characteristics and application limits are presented and the necessity of an extended illumination model is suggested to get more appropriate object colors recovered. The extended illumination model should contain an additional term for the ambient light in order to account for spatial variance of illumination in object images. Its necessity is verified through an experiment under simple lighting environment in this study. Finally, a reconstruction method for recovering input images under standard white light illumination is experimented and an useful method for computing object color reflectivity is suggested and experimented which can be induced from combination of the existing illumination models.

The Model of Illumination-Transillumination for Image Enhancement of Xray Images (조명-투과 영상모델을 이용한 방사선 영상 개선에 관한 연구)

  • Lyu, Kwang-Yeul;Rhee, Sang-Min
    • Journal of radiological science and technology
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    • v.24 no.1
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    • pp.67-73
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    • 2001
  • In digital image processing, the homomorphic filtering approach is derived from an illumination-reflectance model of the image. It can also be used with an illumination-transillumnation model of X-ray film. Several X-ray images were applied to enhancement with histogram equalization and homomorphic filter based on an illumination-transillumination model. The homomorphic filter has proven theoretical claim of image density range compression and balanced contrast enhancement, and also was found a valuable tool to process analog X-ray images to digital images.

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Determination of Water Content in Skin by using a FT Near Infrared Spectrometer

  • Suh Eun-Jung;Woo Young-Ah;Kim Hyo-Jin
    • Archives of Pharmacal Research
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    • v.28 no.4
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    • pp.458-462
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    • 2005
  • The water content of skin was determined using a FT near infrared (NIR) spectrometer. NIR diffuse reflectance spectra were collected from hairless mouse, in vitro, and from human inner arm, in vivo. It was found that the variation of NIR absorbance band 1450 nm from OH vibration of water and 1940 nm from the combination involving OH stretching and OH deformation, depending on the absolute water content of separated hairless mouse skin, in vitro, using the FT NIR spectrometer. Partial least squares regression (PLSR) was applied to develop a calibration model. The PLS model showed good correlation. For practical use of the evaluation of human skin moisture, the PLS model for human skin moisture was developed in vivo on the basis of the relative water content of stratum corneum from the conventional capacitance method. The PLS model predicted human skin moisture with a standard errors of prediction (SEP) of 3.98 at 1130-1830 nm range. These studies showed the possibility of a rapid and nondestructive skin moisture measurement using FT NIR spectrometer.