• Title/Summary/Keyword: active contour model

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Extended Snake Algorithm Using Color Variance Energy (컬러 분산 에너지를 이용한 확장 스네이크 알고리즘)

  • Lee, Seung-Tae;Han, Young-Joon;Hahn, Hern-Soo
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.10
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    • pp.83-92
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    • 2009
  • In this paper, an extended snake algorithm using color variance energy is proposed for segmenting an interest object in color image. General snake algorithm makes use of energy in image to segment images into a interesting area and background. There are many kinds of energy that can be used by the snake algorithm. The efficiency of the snake algorithm is depend on what kind of energy is used. A general snake algorithm based on active contour model uses the intensity value as an image energy that can be implemented and analyzed easily. But it is sensitive to noises because the image gradient uses a differential operator to get its image energy. And it is difficult for the general snake algorithm to be applied on the complex image background. Therefore, the proposed snake algorithm efficiently segment an interest object on the color image by adding a color variance of the segmented area to the image energy. This paper executed various experiments to segment an interest object on color images with simple or complex background for verifying the performance of the proposed extended snake algorithm. It shows improved accuracy performance about 12.42 %.

Region-based Content Retrieval Algorithm Using Image Segmentation (영상 분할을 이용한 영역기반 내용 검색 알고리즘)

  • Rhee, Kang-Hyeon
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.44 no.5
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    • pp.1-11
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    • 2007
  • As the availability of an image information has been significantly increasing, necessity of system that can manage an image information is increasing. Accordingly, we proposed the region-based content retrieval(CBIR) algorithm based on an efficient combination of an image segmentation, an image texture, a color feature and an image's shape and position information. As a color feature, a HSI color histogram is chosen which is known to measure spatial of colors well. We used active contour and CWT(complex wavelet transform) to perform an image segmentation and extracting an image texture. And shape and position information are obtained using Hu invariant moments in the luminance of HSI model. For efficient similarity computation, the extracted features(color histogram, Hu invariant moments, and complex wavelet transform) are combined and then precision and recall are measured. As a experimental result using DB that was supported by www.freefoto.com. the proposed image retrieval engine have 94.8% precision, 82.7% recall and can apply successfully image retrieval system.

Three-Dimensional Active Shape Models for Medical Image Segmentation (의료영상 분할을 위한 3차원 능동 모양 모델)

  • Lim, Seong-Jae;Jeong, Yong-Yeon;Ho, Yo-Sung
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.5
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    • pp.55-61
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    • 2007
  • In this paper, we propose a three-dimensional(3D) active shape models for medical image segmentation. In order to build a 3D shape model, we need to generate a point distribution model(PDM) and select corresponding landmarks in all the training shapes. The manual determination method, two-dimensional(2D) method, and limited 3D method of landmark correspondences are time-consuming, tedious, and error-prone. In this paper, we generate a 3D statistical shape model using the 3D model generation method of a distance transform and a tetrahedron method for landmarking. After generating the 3D model, we extend the shape model training and gray-level model training of 2D active shape models(ASMs) and we use the integrated modeling process with scale and gray-level models for the appearance profile to represent the local structure. Experimental results are comparable to those of region-based, contour-based methods, and 2D ASMs.

Optimal Design Method for an Actively Shielded MRI Superconducting Magnet (능동 차폐 MRI 초전도 자석에 대한 최적 설계 방법)

  • Lee, Kwang-Ho;Cho, Yun-Hyun
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.6
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    • pp.421-430
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    • 2000
  • This paper describes an optimal design method which is applied a weighted least square (WLS) method for Magnetic Resonance Imaging (MRI) system. An optimal design approach is presented for a homogeneity superconducting magnet with the superconducting active shield especially for a magnetic resonance imaging system. The WLS is used to obtain the optimal configurations using the least amount and minimum volume of conductor, exhibiting the smallest level of field inhomogeneity and resulting in the least level of stray field. The proposed model is used to design a multiple-shield configuration for a 1.5 T MRI magnet. The field homogeneity is required less than 5 gauss stray field contour within 4m axially and 3m radially from origin. The designed magnet with the actively magnetic shielding coil out of main coils is analyzed by FEM and theoretical analysis method, investigated the field homogeneity.

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Prediction of ions migration behavior in mortar under 2-D ALMT application to inhibit ASR

  • Liu, Chih-Chien;Kuo, Wen-Ten
    • Computers and Concrete
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    • v.14 no.3
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    • pp.263-277
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    • 2014
  • This study investigated four electric field configurations of two-dimensional accelerate lithium migration technique (ALMT), including line-to-line, plane-to-line, contour-to-line and plane-to-plane, and analyzed the ion migration behavior and efficiency. It was found that the free ion distribution diagram and voltage distribution diagram were similar, and ions migrated in the power line direction. The electrode modules were used for the mortar specimen with w/c ratio of 0.5. The effectively processed areas accounted for 14.1%, 39.0%, 49.4% and 51.4% of total area respectively on Day 28. Larger electrode area was more advantageous to ion migration. In addition, it was proved that the two-dimensional electric field could be divided into different equifield line active regions, and regarded as affected by one-dimensional electric field, and the ion migration results in various equifield line active regions were predicted by using the duration analysis method based on the theoretical model of ion migration obtained from one-dimensional test.

A Multiple Object Detection and Tracking Using Automatic Deformable Model (자동 변형 모델을 이용한 다중 물체 검출 및 추적)

  • 우장명;김성동;최기호
    • Proceedings of the Korea Multimedia Society Conference
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    • 2003.11a
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    • pp.290-293
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    • 2003
  • 다중 물체 추적은 움직이는 물체를 추출하고 검출된 정보와 물체 정보를 이용하여 움직임 궤도률 추적하는 것이다. 따라서 정확한 움직임 추적이 수행되려면 효율적인 물체의 추출이 선행 되어 져야 한다. 일반적으로 영상 분할 알고리즘은 다양한 증류의 영상에 대한 물체의 수학적 모델이 찌대로 설정되어 있지 않기 때문에 물체를 정확하게 분리해 내기 어렵다. 그러나 물체의 추출에 주로 처리 속도가 빠른 배경영상을 이용한 차(difference) 영상 기법과 반 자동 영상분할인 Snake Model이 갖는 Active Contour 알고리즘과 같이 물체 추출 과정에서 물체의 정의니 semantic 정보를 부여 한다면 개선된 영상 분할의 결과를 얻을 수 있다. 따라서 차 영상 기법과 semantic 정보를 가진 영상분할 알고리즘은 동영상에서 움직임 물체의 VOP(Video Object Plane)를 생성하는 매우 현실적인 방법이다. 본 논문에서는 영상의 상위 레벨Semantic 정보를 이용하기 위해 변형 Snake Model를 이용한 영상분할 방법을 이용하여 영상을 추출한다. 추출된 물체는 윤곽선(곡선) 정보와 함께 에지 성분의 기울기에서 얻은 특징 점을 이용하여 물체를 추적해 나간다.

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A Study on 3D CT Image Segmentation and Registration of Mandibular First Premolar (하학 제 1 소구치의 3 차원 CT 영상 분할 및 정합 연구)

  • Jin K.C.;Chun K.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.175-176
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    • 2006
  • The aim of the 3D medical imaging is to facilitate the creation of clinically usable image-based algorithm. Clinically usable imaging algorithm for image analysis requires a high degree of interaction to verify and correct results from registration algorithms, such as the Insight Toolkit (ITK) and the Visualization Toolkit (VTK) which are the class libraries. ITK provides segmentation algorithms and VTK has powerful 3D visualization. However, to apply those libraries to the medical images such as Computerized Tomography (CT), the algorithm based on the interactive construction and modification of data objects are necessary. In this paper we showed the 3D registration about mandibular premolar of human teeth acquired by micro-CT scanner. Also, we used the ITK to find the contour of pulp layer of premolar, furthermore, the 3D imaging was visualized with VTK designed to create one kind of view on the data of 3D visualization. Finally, we evaluated that the volume model of pulp layer would be useful for the tooth morphology in dental medicine.

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Tongue Image Segmentation via Thresholding and Gray Projection

  • Liu, Weixia;Hu, Jinmei;Li, Zuoyong;Zhang, Zuchang;Ma, Zhongli;Zhang, Daoqiang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.2
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    • pp.945-961
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    • 2019
  • Tongue diagnosis is one of the most important diagnostic methods in Traditional Chinese Medicine (TCM). Tongue image segmentation aims to extract the image object (i.e., tongue body), which plays a key role in the process of manufacturing an automated tongue diagnosis system. It is still challenging, because there exists the personal diversity in tongue appearances such as size, shape, and color. This paper proposes an innovative segmentation method that uses image thresholding, gray projection and active contour model (ACM). Specifically, an initial object region is first extracted by performing image thresholding in HSI (i.e., Hue Saturation Intensity) color space, and subsequent morphological operations. Then, a gray projection technique is used to determine the upper bound of the tongue body root for refining the initial object region. Finally, the contour of the refined object region is smoothed by ACM. Experimental results on a dataset composed of 100 color tongue images showed that the proposed method obtained more accurate segmentation results than other available state-of-the-art methods.

Hierarchical Active Shape Model-based Motion Estimation for Real-time Tracking of Non-rigid Object (계층적 능동형태 모델을 이용한 비정형 객체의 움직임 예측형 실시간 추적)

  • 강진영;이성원;신정호;백준기
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.5
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    • pp.1-11
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    • 2004
  • In this paper we proposed a hierarchical ASM for real-time tracking of non-rigid objects. For tracking an object we used ASM for estimating object contour possibly with occlusion. Moreover, to reduce the processing time we used hierarchical approach for real-time tacking. In the next frame we estimated the initial feature point by using Kalman filter. We also added block matching algorithm for increasing accuracy of the estimation. The proposed hierarchical, prediction-based approach was proven to out perform the exiting non-hierarchical, non-prediction methods.

3D-QSAR, Docking and Molecular Dynamics Simulation Study of C-Glycosylflavones as GSK-3β Inhibitors

  • Ghosh, Suparna;Keretsu, Seketoulie;Cho, Seung Joo
    • Journal of Integrative Natural Science
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    • v.13 no.4
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    • pp.170-180
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    • 2020
  • Abnormal regulation, hyperphosphorylation, and aggregation of the tau protein are the hallmark of several types of dementia, including Alzheimer's Disease. Increased activity of Glycogen Synthase Kinase-3β (GSK-3β) in the Central Nervous System (CNS), increased the tau hyperphosphorylation and caused the neurofibrillary tangles (NFTs) formation in the brain cells. Over the last two decades, numerous adenosine triphosphate (ATP) competitive inhibitors have been discovered that show inhibitory activity against GSK-3β. But these compounds exhibited off-target effects which motivated researchers to find new GSK-3β inhibitors. In the present study, we have collected the dataset of 31 C-Glycosylflavones derivatives that showed inhibitory activity against GSK-3β. Among the dataset, the most active compound was docked with the GSK-3β and molecular dynamics (MD) simulation was performed for 50 ns. Based on the 50 ns MD pose of the most active compound, the other dataset compounds were sketched, minimized, and aligned. The 3D-QSAR based Comparative Molecular Field Analysis (CoMFA) model was developed, which showed a reasonable value of q2=0.664 and r2=0.920. The contour maps generated based on the CoMFA model elaborated on the favorable substitutions at the R2 position. This study could assist in the future development of new GSK-3β inhibitors.