• Title/Summary/Keyword: Sobel

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A Study on the Depth Map using Single Edge (단일 엣지를 이용한 깊이 정보에 관한 연구)

  • Kim, Young-Seop;Song, Eung-Yeol
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.2
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    • pp.123-126
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    • 2010
  • An implementation of modified stereo matching using efficient belief propagation (BP) algorithm is presented in this paper. We do recommend the use of the simple sobel, prewitt edge operator. The application of B band sobel edge operator over image demonstrates result with somewhat noisy (distinct border). When we adopt the only MRF + BP algorithm, however, borders cannot be distinguished due to that the message functions in the BP algorithm is just the mechanism which passes energy data to the only large gap of each Message functions In order to address the abovementioned disadvantageous phenomenon, we use the sobel edge operator + MRF + BP algorithm to distinguish the border that is located between the similar message data. Using edge information, the result shows that our proposed process diminishes the propagation of wrong probabilistic information. The enhanced result is due to that our proposed method effectively reduced errors incurred by ambiguous scene properties.

A Study on the Extraction of Feature by State-Space Concept with Euclidean Distance Operator (Euclidean 거리연산자와 결합된 상태공간 기법에 의한 영상추출)

  • Choi, Kap Seok;Yoon, Dong Han
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.23 no.6
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    • pp.846-852
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    • 1986
  • An efficient and reliable method for the extraction of features is presented. The method utilizes by a state technique with Euclidean distance operator. The proposed method is compared with the Sobel Operator. Simulation results show that our method performs as well as the Sobel operator.

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A Study on Edge Detection using Gray-Level Transformation Function (그레이 레벨 변환 함수를 이용한 에지 검출에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.12
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    • pp.2975-2980
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    • 2015
  • Edge detection is one of image processing techniques applied for a variety of purposes in a number of areas and it is used as a necessary pretreatment process in most applications. Detect this edge has been conducted in various fields at domestic and international. In the conventional edge detection methods, there are Sobel, Prewitt, Roberts and LoG, etc using a fixed weights mask. Since conventional edge detection methods apply the images to the fixed weights mask, the edge detection characteristics appear somewhat insufficient. Therefore in this study, to complement this, preprocessing using gray-level transformation function and algorithm finding final edge using maximum and minimum value of estimated mask by local mask are proposed. And in order to assess the performance of proposed algorithm, it was compared with a conventional Sobel, Roberts, Prewitt and LoG edge detection methods.

A Study on Edge Detection Algorithm using Mask Shifting Deviation (마스크 이동 편차를 이용한 에지 검출 알고리즘에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.8
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    • pp.1867-1873
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    • 2015
  • Edge detection is one of image processing techniques applied for a variety of purposes in a number of areas and it is used as a necessary pretreatment process in most applications. In the conventional edge detection methods, there are Sobel, Prewitt, Roberts and LoG, etc using a fixed weights mask. Since conventional edge detection methods apply the images to the fixed weights mask, the edge detection characteristics appear somewhat insufficient. Therefore in this study, an algorithm for detecting the edge is proposed by applying the cross mask based on the center pixel and up, down, left and right mask based on the surrounding pixels of center pixel in order to solve these problems. And in order to assess the performance of proposed algorithm, it was compared with a conventional Sobel, Roberts, Prewitt and LoG edge detection methods.

A Study on Mask-based Edge Detection Algorithm using Morphology (모폴로지를 이용한 마스크 기반 에지 검출 알고리즘에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.10
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    • pp.2441-2449
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    • 2015
  • In this digital information era, utilization of images are essential for various media, and the edge is an important characteristical information of an object in images that includes the size, location, direction and etc. Many domestic and international studies are being conducted in order to detect these edge. Existing edge detection methods include Sobel, Prewitt, Roberts, Laplacian, LoG and etc. which apply fixed weight value. As these existing edge detection methods apply fixed weight mask to the image, edge detection characteristic appears slightly insufficient. Accordingly, in order to supplement these problems, this study used bottom-hat transformation from mathematical morphology and opening operation in improving the image and proposed an algorithm that detects for the edge after calculating mask-based gradient. And to evaluate the performance of the proposed algorithm, a comparison was made against the existing Sobel, Roberts, Prewitt, Laplacian, LoG edge detection methods, in illustrating visual images, and similarities were compared by calculating the MSE value based on the standard of each image.

Building Extraction and Digital Surface Models Generation from Stereo pairs of Aerial Images (입체 항공사진영상을 이용한 DSM생성 및 건물경계추출)

  • 유환희;김성우;성민규
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.16 no.2
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    • pp.177-185
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    • 1998
  • There is an increasing request for 3D data and outlines on building for urban planning and design. This paper describes an approach to extract building using Digital Surface Models(DSM) and stereo pairs of aerial images. DSM contain informations not only about the topographic surface like Digital Elevation Models(DEM), but also about buildings and other objects higher than the surrounding topographic surface, e.g. tees. We therefore describe our approach consisting of two step procedures. The first step of the approach is to generate DSM by stereo matching using Maximum Likelihood Estimation and Dynamic Programming. The proposed stereo matching is using the cost function for finding the disparity between the left and right image, and the Dynamic Programming for solving the stereo matching problem. The second step is to detect building outlines using the DSM and the edge informations extracted from a digital aerial image by Sobel Operator. The overlay analysis of the DSM and the edge information by Sobel Operator was efficient to detect building outlines.

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Effect of Social Participation Influencing Elderly's Suicidal Ideation (사회참여가 노인 자살생각에 미치는 영향 -사회적 지지와 자기효능감의 매개효과를 중심으로-)

  • Jeong, Il-Young
    • The Journal of the Korea Contents Association
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    • v.13 no.9
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    • pp.164-177
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    • 2013
  • This study's aim was to attest social support and self-efficacy's mediation effects in the path which social participation affected to elderly's suicidal ideation. Analysis data were Seoul Welfare Panel Data 2th wave(2010). A total of 1,429 cases aged over 65 were used for this study. Analysis method was AMOS 18.0's Structural Equation Modeling, and sobel test was used for attesting mediation effects's significance degree. Analysis results had established that measurement model and structural model's fit was favorable, and all path coefficients had significance degree. Therefore, this model was suitable for this study. Also this results had proved that this study's model was full mediation model, and it means that if mediation variables controlled, and then direct effect was excluded. And analysis results confirmed social support and self-efficacy' mediation effect had significance, by using a sobel test. Based on analysis results, this study suggested the importance of relationship between secondary group and individual, and presented intervention plans.

Factors Influencing Subjective Happiness in Korean Nursing Students (간호대학생의 주관적 행복감에의 영향요인)

  • Kim, Eun Man;Yang, Young Hee;Lee, Haeyoung;Yu, Mi
    • The Journal of Korean Academic Society of Nursing Education
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    • v.22 no.3
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    • pp.294-303
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    • 2016
  • Purpose: The purpose of this study was to determine subjective happiness related factors in Korean nursing students. Methods: A purposive sample of 200 nursing students was recruited for the cross-sectional survey design. The instruments were perceived stress scale, major satisfaction scale, resilience scale, and subjective happiness scale. Data were analyzed using descriptive statistics, hierarchical linear regression, and the Sobel test for testing mediating effects. Results: The mean score of stress, major satisfaction, resilience and subjective happiness was 2.21, 3.95, 3.60 and 5.03, respectively. Perceived health status, stress_positive perception, stress_negative perception, resilience_self confidence, resilience_positivity, resilience_social support had significant effects on subjective happiness. Explained variance for the subjective happiness was 53.4%. Resilience had a partial mediating effect in the relationship between stress and subjective happiness (Sobel test: Z=-5.67, p<.001). Also, resilience had a mediating effect in the relationship between major satisfaction and subjective happiness (Sobel test: Z=5.65, p<.001). Conclusion: Based on the findings of this study, nursing intervention programs focusing on improving resilience are recommended to improve subjective happiness in nursing students.

Smartphone Addiction and Depression: The Mediating Effects of Self-esteem and Resilience among Middle School Students (중학생의 스마트폰 중독과 우울: 자아존중감과 적응유연성의 매개효과)

  • Park, Hyejung;Choi, Eunsuk
    • Research in Community and Public Health Nursing
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    • v.28 no.3
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    • pp.280-290
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    • 2017
  • Purpose: The aim of this research is to examine the moderating effects of self-esteem and resilience in the relationship between smartphone addiction and depression among middle school students. Methods: Data were collected from 324 middle school students in D City during the period of July 1st-17th, 2015. Multiple regression analysis, the Baron & Kenny's mediation verification, and Sobel test were conducted to measure the mediating effects of self-esteem and resilience on depression. Results: There were significant correlations among the variables; smartphone addiction, self-esteem, resilience, and depression. Self-esteem had a complete mediating effect (${\beta}=-.40$, p<.001) in the relationship between smartphone addiction and depression (Sobel test: Z=4.68, p<.001). Resilience had a partial mediating effect (${\beta}=-.15$, p<.001) in the relationship between smartphone addiction and depression (Sobel test: Z=2.40, p<.001). Conclusion: This study suggests to apply self-esteem and resilience in developing nursing intervention programs for adolescent depression caused by smartphone addiction.

A Study on the Edge Detection for Road Information based on the IKONOS (IKONOS 영상에서 도로정보추출을 위한 경계검출에 관한 연구)

  • Choi, Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.3
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    • pp.593-598
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    • 2006
  • High-resolution satellite imagery has many benefits, compared to aerial photo in the wide area as well as multi-spectral character. So, it can be used well for constructing GIS data when making digital map. This study analysed the possibilities that road information derived automatically from IKONOS can be used for making ITS system or updating digital map of the urban areas where change frequently and producing satellite image map. In this study, Sobel was applied for road edge dectection after low pass filtering. As the results, it's possible for low pass filtering and high pass filtering to be used as the basic data for ITS construction when extracting edge roads and constructs according to the characteristic of high-resolution satellite imagery.