• Title/Summary/Keyword: brightness mean

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The Analysis Errors of Surface Water Temperature Using Landsat TM (Landsat TM을 이용한 표층수온 분석 오차)

  • 정종철;유신재
    • Korean Journal of Remote Sensing
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    • v.15 no.1
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    • pp.1-8
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    • 1999
  • The estimation technique of surface water temperature by satellite remote sensing has been applied to ocean and large lakes using AVHRR. However, the spatial resolution AVHBR is not abquate for coastal region and small lakes. Landsat 5 TM has 120 m spatial resolution, which suits better. We carried out analysis of surface water temperature in Lake Sihwa and near coastal area using Landsat 5 TM. To relate digital number to the brightness temperature, we applied Empirical, NASA, RESTEC, Quadratic methods. Comparing calculated and observed value, we obtained as follows; NASA method, $R^2=0.9343$, RMSE(Root Mean Square Error)=3.5876$^{\circ}C$; RESTEC method, $R^2=0.8937$, RMSE=3.76$^{\circ}C$; Quadratic method, $R^2=0.8967$, RMSE=2.949$^{\circ}C$. Because Landsat TM has only one band for extracting surface temperature, it was difficult to correct for the atmospheric errors. For improving the accuracy of surface temperature detection using Landsat TM, there is a need for a method to decrease the effect of atmospheric contents.

The effect of mean brightness and contrast of digital image on detection of watermark noise (디지털 영상의 밝기와 대비에 따른 워터 마크 잡음 강도의 차이)

  • Kham, Kee-Taek;Moon, Ho-Seok;Yoo, Hun-Woo;Chung, Chan-Sup
    • Proceedings of the Korean Society for Cognitive Science Conference
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    • 2005.05a
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    • pp.125-129
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    • 2005
  • 디지털 영상물에 대한 저작권을 보호하기 위해 저작권자의 고유한 영상을 기존 디지털 영상에 삽입하는 것을 워터 마킹이라고 부른다. 삽입된 워터 마크가 효과적으로 사용되기 위해서는 영상의 다양한 왜곡이나 변형에도 강건할 수 있게 그 강도가 강해야 하며, 동시에 워터 마크가 삽입된 영상의 왜곡을 식별할 수 없게 그 강도를 약하게 하여야 한다. 비가시성을 유지한 채 가능한 한 강한 워터마크를 삽입하는 것은 워터마크를 적용 하는 데 매우 중요한 문제이다. 대부분의 워터 마크 알고리듬에서 삽입될 워터 마크의 강도는 원영상과 워터마크 영상간의 물리적인 차이에 근거하여 계산된 특정 값으로 고정한 채, 이 값을 모든 영상에 동일하게 적용하고 있다. 인간의 경우 자극의 탐지는 주변 영상의 밝기나 대비 등 여러 요소에 의해 변화되므로 디지털 영상에 삽입된 워터 마크의 탐지도 영상의 특징에 따라서 변화될 수 있다. 본 연구에서는 원영상으로부터 세 수준의 밝기와 세 수준의 대비를 갖는 기본 영상들을 만든 후, 기본 영상에서 탐지될 수 있는 워터 마크의 강도가 변화되는 지를 살펴보았다. 연구 결과 영상의 밝기가 밝아질수록, 대비가 커질수록 지각될 수 있는 워터 마크의 강도는 더 커지는 것으로 나타났다. 또한 회귀분석을 통해 영상의 밝기와 대비에 근거하여 삽입될 워터 마크의 강도를 결정할 수 있는 회귀 식을 만들어 내었다. 이러한 회귀 식은 주어진 영상의 통계 치에 근거하여 워터 마크 강도를 적응적으로 변화시킬 수 있는 알고리듬을 개발하는 데 유용하게 사용될 수 있을 것이다.

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An α-cut Automatic Set based on Fuzzy Binarization Using Fuzzy Logic (퍼지논리를 이용한 α-cut 자동 설정 기반 퍼지 이진화)

  • Lee, Ho Chang;Kim, Kwang Baek;Park, Hyun Jun;Cha, Eui-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.12
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    • pp.2924-2932
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    • 2015
  • Image binarization is a process to divide the image into objects and backgrounds, widely applied to the fields of image analysis and its recognition. In the existing method of binarization, there is some uncertainty when there is insufficient brightness gap between objects and backgrounds in setting threshold. The method of fuzzy binarization has improved the features of objects efficiently. However, since this method sets ${\alpha}$-cut value statically, there remain some problems that important features of objects can be lost during binarization. Therefore, in this paper, we propose a binarization method which does not set ${\alpha}$-cut value statically. The proposed method uses fuzzy membership functions calculated by thresholds of mean, iterative, and Otsu binarization. Experiment results show the proposed method binaries various images with less loss than the existing methods.

Optimum Use of Forest Biomass Generated from the National Forest Management Operation (Part 1) - Study of Characteristics of Kraft Pulps Made from Single Wood Species - (숲가꾸기 산물의 최적용도 개발을 위한 연구 (제1보) - 단일 수종으로 제조된 크라프트 펄프의 특성 연구 -)

  • Park, Hyun-Jin;Kim, Chul-Hwan;Lee, Jee-Young;Lee, Gyeong-Sun;Lee, Ji-Young;Sheikh, M.I.;Sim, Sung-Woong;Yim, Su-Jin;Lee, Young-Min;Ahn, Byung-Il
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.44 no.5
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    • pp.63-71
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    • 2012
  • This study was carried out to investigate pulping properties of the forest biomass arising from the national forest management operation. The forest biomass was collected and classified into many groups according to their species and age. After the chips were made from the forest biomass, the measurement of chip size and chemical analysis were performed. To make the pulps from the forest biomass, the kraft pulping was applied and thereafter the physical and optical properties of kraft pulps were measured. The pulp fibers from the forest biomass had the similar mean fiber length, but their properties became different according to wood species and ages. Differently from the other species, kraft pulps from chestnut wood had the highest kappa number. Acacia, paulownia and chestnut woods made kraft pulps with lower tensile strength and brightness than the others. It could be concluded that acacia, paulownia and chestnut woods must be screened out in order to make a good quality of kraft pulps while being collected during Forest Management Operation.

The Fabrication and Design of Driving Circuit for LCD panel using the high efficiency LED (고 효율 LED를 이용한 LCD 패널 구동회로의 설계 및 제작)

  • Ryu, Jang-Ryeol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.7
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    • pp.3146-3151
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    • 2012
  • For using them as a optical source of inspections equipment for LCD panel, the design ofexcellent backlight system, brightness uniformity and high power and good protection against heat is essential.In this paper, backlight system which is built in the 45 inch side emitting LCD backlight by LED arraystructure and driving circuit were designed and developed. After that, their performances were measured. Itshowed the luminance from 3,000 to 25,000[$cd/m^2$], the mean value x:0.3144, y:0.3076 of x-y chromaticity,dimming range of 27~515[$cd/m^2$], free flicker noise in the 80kHz and black level of 0.7~0.1[$cd/m^2$], thermaltest of cooling system in 20,000[$cd/m^2$] over values.

Morphological Characteristics of Korean Dried Ginseng Products

  • Hong, Hee-Do;Cho, Chang-Won;Kim, Young-Chan;Kim, Eun-Young;Rhee, Young-Kyung;Rho, Jeong-Hae;Choi, Seung-Hoe
    • Journal of Ginseng Research
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    • v.36 no.3
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    • pp.314-321
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    • 2012
  • The purpose of this study was to determine a standard quality characteristic through the evaluation and statistical analysis of the morphological characteristics of dried ginseng (white ginseng) products. Samples of 4-year-old 30 and 50 piece grade curved ginseng and 5-year-old 25 and 15 piece grade straight ginseng products were collected from a market, with 5 to 10 packs of each product being collected annually over a 5-year period (2006-2010). Morphological characteristics, such as weight, length, diameter, and surface color, were measured and statistically analyzed to present a standard quality characteristic value using $mean{\pm}3SD$, a range that excluded outlier. The 4-year-old curved ginseng samples of 50 and 30 piece grade were 4.80 to 6.12 cm and 5.28 to 7.60 cm long, 0.22 to 1.70 cm and 0.21 to 2.07 cm wide, and weighed 5.28 to 7.40 g and 8.62 to 12.26 g, respectively. The 5-year-old straight ginseng samples of 25 and 15 piece grade were 9.66 to 15.47 cm and 10.66 to 16.80 cm long, 1.32 to 1.94 cm and 1.48 to 2.43 cm wide, and weighed 9.18 to 16.40 g and 15.89 to 24.82 g, respectively. The surface color of the different piece grades in the same type of dried ginseng product was similar, whereas the straight ginseng demonstrated a lower level of brightness, but the relative redness and yellowness were of higher levels, than that of curved ginseng.

The effect of young stellar populations in Early-type galaxies

  • Suh, Hye-Won;Jeong, Hyun-Jin;Oh, Kyu-Seok;Yi, Suk-Young K.;Ferreras, Ignacio;Schawinski, Kevin
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.74.1-74.1
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    • 2010
  • We have investigated the radial g-r color gradients of early-type galaxies in the Sloan Digital Sky Survey (SDSS) DR6 in the redshift range 0.00$H{\beta}$ absorption-line strengths and/or emission-line ratios that are indicative of the presence of young stellar populations. This implies that most of the residual star formation in early-type galaxies is centrally concentrated. Blue-cored galaxies are predominantly low-velocity dispersion systems. A simple model shows that the observed positive color gradients are visible only for a billion years after a star formation episode for the typical strength of recent star formation. The observed effective radius decreases and the mean surface brightness increases due to this centrally concentrated star formation episode. As a result, the majority of blue-cored galaxies may lie on different regions in the fundamental plane (FP) from red-cored ellipticals. However, the position of the blue-cored galaxies on the FP cannot be solely attributed to recent star formation but requires substantially lower velocity dispersion. We conclude that a low-level of residual star formation persists at the centers of most of low-mass early-type galaxies, whereas massive ones are mostly quiescent systems with metallicity-driven red cores.

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A Study on Store Image Preferences which is Followed by Clothing Buying Motives -As Object of Middle Age Women- (의복구매동기에 따른 점포이미지 선호도에 관한 연구 -중상층 중년여성을 중심으로-)

  • Lee Joo Eun;Lim Sook Ja
    • Journal of the Korean Society of Clothing and Textiles
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    • v.14 no.4 s.36
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    • pp.252-261
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    • 1990
  • This study intends to provide a beneficial foundation which can aid our understanding of how a clothing consumer group can be classified according to the clothing buying motives, and what differences are there about the importances of stroe image attribute among them and how consumer's preferences to the store image are shown differently among them and ultimately, some concrete data which can be useful in establishing efficient store image strategies for clothing stores. 413 subjects were gathered through convenience sampling method and, for data analysis, cronbach'$\alpha$, frequency, percentage, mean, $x^{2}-text$, 1-test, ANOVA, Duncan Multiple Range Test, Factor Analysis, Cluster Analysis were conducted. The results are as follows; 1. Three kind of factors in the clothing buying motives were determined for analysis of consumers group and by which it was revealed as to be significant for us to classify them four subdivisions; those of fashion pursuit group, self display group, financial utilitarian group, individual group. 2. Importance on store image attribute was revealed then the middle aged women regarded quality, price, service in order as more important factors than others. 3. Store image preferences show significantly when concerned with quality, price, fashion, impression and age of store personnel, convenience for exchanging and returning goods, credit, delivery and repair, mailing of catalogue and discount coupon, exit from, brightness of store among consumer groups. From these findings, concretely store image strategies are proposed.

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A Study on Improvement in Digital Image Restoration by a Recursive Vector Processing (순환벡터처리에 의한 디지털 영상복원에 관한 연구)

  • 이대영;이윤현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.8 no.3
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    • pp.105-112
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    • 1983
  • This paper discribes technique of the recursive restoration for the images degraded by linear space invariant blur and additive white Gaussian noise. The image is characterized statistically by tis mean and correlation function. An exponential autocorrelation function has been used to model neighborhood model. The vector model was used because of analytical simplicitly and capability to implement brightness correlation function. Base on the vector model, a two-dimensional discrete stochastic a 12 point neighborhood model for represeting images was developme and used the technique of moving window processing to restore blurred and noisy images without dimensionality increesing, It has been shown a 12 point neighborhood model was found to be more adequate than a 8 point pixel model to obtain optimum pixel estimated. If the image is highly correlated, it is necessary to use a large number of points in the neighborhood in order to have improvements in restoring image. It is believed that these result could be applied to a wide range of image processing problem. Because image processing thchniques normally required a 2-D linear filtering.

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Demography of SDSS Early-type galaxies from the perspective of radial color gradients

  • Suh, Hye-Won;Jeong, Hyun-Jin;Oh, Kyu-Seok;Yi, Suk-Young K.;Ferreras, Ignacio;Schawinski, Kevin
    • Bulletin of the Korean Space Science Society
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    • 2009.10a
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    • pp.34.4-35
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    • 2009
  • We have studied the radial g-r color gradients of early-type galaxies in the Sloan Digital Sky Survey (SDSS) DR6 in the redshift range 0.00 < z < 0.06. The color profiles of ~30 per cent of the galaxies in this sample show positive color gradients (centers being bluer). These positive gradient galaxies often show strong $H\beta$ absorption line strengths or emission line ratios that are consistent with star-forming populations. Combining the optical data with Galaxy Evolution Explorer (GALEX) UV photometry, we find that all positive gradient galaxies show blue UV-optical colors. They also exhibit a tendency of having a lower stellar velocity dispersion. Positive gradient galaxies tend to live in lower density regions than negative gradient galaxies and are likely to have a late-type companion galaxy. On the other hand, massive early-type galaxies show negative color gradients. A simplistic population analysis shows that these positive color gradients are visible only for half a billion years after a star burst. Although the effective radius decreases and mean surface brightness increases due to this centrally concentrated star formation, the positions of the positive gradient galaxies on the fundamental plane cannot be reproduced by any amount of recent star formation. Instead it required a lower velocity dispersion.

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