• Title/Summary/Keyword: 영역/경계 분할

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Fuzzy-based Segmentation Algorithm for Brain Images (퍼지기반의 두뇌영상 영역분할 알고리듬)

  • Lee, Hyo-Jong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.12
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    • pp.102-107
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    • 2009
  • As technology gets developed, medical equipments are also modernized and leading-edge systems, such as PACS become popular. Many scientists noticed importance of medical image processing technology. Technique of region segmentation is the first step of digital medical image processing. Segmentation technique helps doctors to find out abnormal symptoms early, such as tumors, edema, and necrotic tissue, and helps to diagnoses correctly. Segmentation of white matter, gray matter and CSF of a brain image is very crucial part. However, the segmentation is not easy due to ambiguous boundaries and inhomogeneous physical characteristics. The rate of incorrect segmentation is high because of these difficulties. Fuzzy-based segmentation algorithms are robust to even ambiguous boundaries. In this paper a modified Fuzzy-based segmentation algorithm is proposed to handle the noise of MR scanners. A proposed algorithm requires minimal computations of mean and variance of neighbor pixels to adjust a new neighbor list. With the addition of minimal compuation, the modified FCM(mFCM) lowers the rate of incorrect clustering below 30% approximately compared the traditional FCM.

An Edge Preserving Color Image Segmentation Using Mean Shift Algorithm and Region Merging Method (Mean Shift 알고리즘과 영역 병합 방법을 이용한 경계선 보존 컬러 영상 분할)

  • Kwak Nae-Joung;Kwon Dong-Jin;Kim Young-Gil
    • The Journal of the Korea Contents Association
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    • v.6 no.9
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    • pp.19-27
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    • 2006
  • Mean shift procedure is applied for the data points in the joint spatial-range domain and achieves a high quality. However, a color image is segmented differently according to the inputted spatial parameter or range parameter and the demerit is that the image is broken into many small regions in case of the small parameter. In this paper, to improve this demerit, we propose the method that groups similar regions using region merging method for over-segmented images. The proposed method converts a over-segmented image in RGB color space into in HSI color space and merges similar regions by hue information. Here, to preserve edge information, the region merge constraints are used to decide whether regions are merged or not. After then, we merge the regions in RGB color space for non-processed regions in HSI color space. Experimental results show the superiority in region's segmentation results.

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Image Segmentation Using Mathematical Morphology (수리형태학을 이용한 영상 분할)

  • Cho Sun-gil;Kang Hyunchul
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.11C
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    • pp.1076-1082
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    • 2005
  • Recently, there have been much efforts in the image segmentation using morphological approach. Among them, the watershed algorithm is one of powerful tools which can take advantages of both of the conventional edge-based segmentation and region-based segmentation. The concept of watershed is based on topographic analogy. But, its high sensitivity to noise yields a very large number of resulting segmented regions which leads to oversegmentation. So we suggest the restricted waterfall algorithm which reduce the oversegmentation by eliminate not only local minima but also local maxima. As a result, the restricted waterfall algorithm has a good segmented image than the other methods, and has a better binary image than the histogram thresholding method.

Semi-automation Image segmentation system development of using genetic algorithm (유전자 알고리즘을 이용한 반자동 영상분할 시스템 개발)

  • Im Hyuk-Soon;Park Sang-Sung;Jang Dong-Sik
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.4 s.42
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    • pp.283-289
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    • 2006
  • The present image segmentation is what user want to segment image and has been studied for technology in composition of segment object with other images. In this paper, we propose a method of novel semi-automatic image segmentation using gradual region merging and genetic algorithm. Proposed algorithm is edge detection of object using genetic algorithm after selecting object which user want. We segment region of object which user want to based on detection edge using watershed algorithm. We separated background and object in indefinite region using gradual region merge from Segment object. And, we have applicable value which user want by making interface based on GUI for efficient perform of algorithm development. In the experiments, we analyzed various images for proving superiority of the proposed method.

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Tooth Region Segmentation by Oral Cavity Model and Watershed Algorithm (구강구조모델과 워터쉐드를 이용한 치아영역 분할)

  • Na, S.D.;Lee, G.H.;Lee, J.H.;Kim, M.N.
    • Journal of Korea Multimedia Society
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    • v.16 no.10
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    • pp.1135-1146
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    • 2013
  • In this paper, we proposed a new algorithm for individual tooth region segmentation on tooth color images. The proposed algorithm used oral cavity model based on structural feature of tooth and new boundary of watershed algorithm. First, the gray scale image is obtained with emphasized tooth regions from the color images and unnecessary regions are removed on tooth images. Next, the image enhancement of tooth images is implemented using the proposed oral cavity model, and the individual tooth regions are segmented by watershed algorithm on the enhanced images. Boundary and seeds necessary to watershed algorithm are applied boundary of binary image using minimum thresholding and region maximum value. In order to evaluate performance of proposed algorithm, we conduct experiment to compare conventional algorithm with proposed algorithm. As a result of experiment, we confirmed that the proposed algorithm is more improved detection ratio than conventional algorithm at molar regions and the tooth region detection performance is improved by preventing overlap detection on oral cavity.

Moving Object Segmentation Using Spatio-temporal Entropic Thresholding (시공간 엔트로피 임계법을 이용한 형태학적 이동 객체 분할)

  • 백경환;신민수;곽노윤
    • Proceedings of the Korea Multimedia Society Conference
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    • 2003.05b
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    • pp.410-414
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    • 2003
  • 본 논문은 비디오 시퀀스에 카메라 패닝 보상과 2차원 시공간 엔트로피 임계법을 적용하여 추출한 객체포함영역을 대상으로 영상 분할을 수행하는 이동 객체 분할 기법에 관한 것이다. 우선, 웨이블렛 변환에 의해 구성한 피라미드 계층 구조상에서 카메라 패닝 벡터를 추정하여 전역 움직임을 보상한다. 이후, 전역 움직임이 보상된 기준영상을 대상으로 각 프레임간에서 2차원 시공간 엔트로피 임계법을 적용하여 이동 객체가 포함될 가능성이 있는 영역을 블록 단위로 추출한다. 다음으로, 2차원 시공간 엔트로피 입계법에 의해 분류된 영역을 토대로 각 블록을 움직임블록, 준 움직임 블록, 비 움직임 블록 중 어느 하나로 분류한 검색 테이블을 작성한다. 이어서, 검색 테이블을 참조하여 초기 탐색 계층 및 탐색 영역을 적응적으로 선정함으로써 피라미드 계층 구조상에서 효율적인 고속 움직임 추정을 수행하여 이동 객체에 해당하는 객체포함영역만을 추출한다. 최종적으로, 이렇게 추출된 객체포함영역에서 임계 기울기 영상을 정의한 후, 이를 기준 삼아 객체포함영역에 화소 단위의 형태학 기반 영상 분할 알고리즘을 적용함으로써 비디오 시퀀스에 포함된 이동 객체를 분할한다. 컴퓨터 시뮬레이션 결과를 통해 고찰할 때, 제안된 방법은 이동 객체에 대한 상대적으로 우수한 분할 특성을 제공할 수 있고, 특히 저대조 경계면의 분할 특성을 제고시키고 있음을 확인할 수 있다.

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3D Region Growing Algorithm based on Eigenvalue of Hessian matrix for Extraction of blood vessels (혈관추출을 위한 Hessian 행렬 고유치 기반 3 차원 영역확장 알고리즘)

  • Lee, Yu-Bu;Choi, Yoo-Joo;Kim, Myoung-Hee
    • Proceedings of the Korea Information Processing Society Conference
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    • 2004.05a
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    • pp.1641-1644
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    • 2004
  • 3차원 볼륨데이터에서 분할 대상영역의 밝기 값이 다양하면서 밝기 값이 유사한 영역과 인접한 경우 3차원 영역확장(region growing) 방법을 사용하여 영역을 분할하기 위해서는 영역확장의 중요한 요인인 동질성 기준 값의 적절한 선택이 요구된다. 본 논문에서는 영역 복셀(voxel)의 1차 미분 값의 크기인 기울기 크기(gradient magnitude)만으로 영역의 경계를 찾기가 쉽지않은 대상의 분할을 위해 볼륨데이터의 지역적인 밝기 값의 변화의 특징을 고려하면서 분할 대상영역의 복셀의 2차 미분(second partial derivation)을 행렬의 요소(element)로 갖는 Hessian 행렬의 고유치(eigenvalue)를 영역확장의 문턱치 결정에 이용하였다. 제안한 알고리즘은 3차원 영역확장의 결과에 가장 큰 영향을 미치는 적절한 문턱치의 선택으로 대상영역의 분할을 성공적으로 수행하여 3차원 영역확장의 단점을 보완하였다.

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An Automatic Segmentation Method for Video Object Plane Generation (비디오 객체 생성을 위한 자동 영상 분할 방법)

  • 최재각;김문철;이명호;안치득;김성대
    • Journal of Broadcast Engineering
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    • v.2 no.2
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    • pp.146-155
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    • 1997
  • The new video coding standard Iv1PEG-4 is enabling content-based functionalities. It requires a prior decomposition of sequences into video object planes (VOP's) so that each VOP represents moving objets. This paper addresses an image segmentation method for separating moving objects from still background (non-moving area) in video sequences using a statistical hypothesis test. In the proposed method. three consecutive image frames are exploited and a hypothesis testing is performed by comparing two means from two consecutive difference images. which results in a T-test. This hypothesis test yields a change detection mask that indicates moving areas (foreground) and non-moving areas (background), Moreover. an effective method for extracting

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Medical Image Data Compression Based on the Region Segmentation (영역분할을 기반으로 한 의료영상 데이타 압축)

  • 김진태;두경수
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.3
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    • pp.597-605
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    • 1999
  • In this paper, we propose a cardioangiography sequence image coding scheme which use a subtraction between initial image and current frame inserted contrast dye. Stable regions are obtained by the multithreshold and meaningful region is extracted by the images with stable region. The image with meaningful region is classified into contour and texture information. Contour information is coded by contour coding. And texture information is approximated by two-dimensional polynomial function and each coefficients is coded. Experimental results confirm that the sequence of cardioangiography are well reconstructed at the low bit rate (0.02∼0.04 bpp) and high compression ratio.

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Automatic Tumor Segmentation Method using Symmetry Analysis and Level Set Algorithm in MR Brain Image (대칭성 분석과 레벨셋을 이용한 자기공명 뇌영상의 자동 종양 영역 분할 방법)

  • Kim, Bo-Ram;Park, Keun-Hye;Kim, Wook-Hyun
    • Journal of the Institute of Convergence Signal Processing
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    • v.12 no.4
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    • pp.267-273
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    • 2011
  • In this paper, we proposed the method to detect brain tumor region in MR images. Our method is composed of 3 parts, detection of tumor slice, detection of tumor region and tumor boundary detection. In the tumor slice detection step, a slice which contains tumor regions is distinguished using symmetric analysis in 3D brain volume. The tumor region detection step is the process to segment the tumor region in the slice distinguished as a tumor slice. And tumor region is finally detected, using spatial feature and symmetric analysis based on the cluster information. The process for detecting tumor slice and tumor region have advantages which are robust for noise and requires less computational time, using the knowledge of the brain tumor and cluster-based on symmetric analysis. And we use the level set method with fast marching algorithm to detect the tumor boundary. It is performed to find the tumor boundary for all other slices using the initial seeds derived from the previous or later slice until the tumor region is vanished. It requires less computational time because every procedure is not performed for all slices.