• 제목/요약/키워드: Boundary detection

검색결과 618건 처리시간 0.025초

디지탈 혈관 조영상에서의 좌심실 경계 자동검출을 이용한 심박출 계수의 측정 (A Measurement of Heart Ejection Fraction using Automatic Detection of Left Ventricular Boundary in Digital Angiocardiogram)

  • 구본호;이태수
    • 대한의용생체공학회:의공학회지
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    • 제8권2호
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    • pp.177-188
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    • 1987
  • Detection of left ventricular boundary for the functional analysis of LV(left ventricle) is obtained using automatic boundary detection algorithm based on dynamic program ming method. This scheme reduces the edge searching time and ensures connective edge detection, since it does not require general edge operator, edge thresholding and linking process of other edge detection methods. The left ventricular diastolic volume and systolic volume were computed after this automatic boundary detection, and these volume data were applied to analyze LV ejection fraction.

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디지탈 혈관 조영장치를 이용한 실시간 영상처리와 심장파라미터의 측정 (Real time image processing and measurement of heart parameter using digital subtraction angiography)

  • 신동익;구본호;박광석;민병구;한만청
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.570-574
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    • 1990
  • Detection of left ventricular boundary for the functional analysis of LV(left ventricle)is obtained using automatic boundary detection algorithm based on dynamic programming method. This scheme reduces the edge searching time and ensures connective edge detection, since it does not require general edge operator, edge thresholding and linking process of other edge. detection methods. The left ventricular diastolic volume and systolic volume and systolic volume were computed after this automatic boundary detection, and these Volume data wm applied to analyze LV ejection fraction.

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셀룰라 병렬처리 회로망에 의한 동적계획법 설계와 자율주행 자동차를 위한 도로 윤곽 검출 (Cellular Parallel Processing Networks-based Dynamic Programming Design and Fast Road Boundary Detection for Autonomous Vehicle)

  • 홍승완;김형석
    • 대한전기학회논문지:시스템및제어부문D
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    • 제53권7호
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    • pp.465-472
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    • 2004
  • Analog CPPN-based optimal road boundary detection algorithm for autonomous vehicle is proposed. The CPPN is a massively connected analog parallel array processor. In the paper, the dynamic programming which is an efficient algorithm to find the optimal path is implemented with the CPPN algorithm. If the image of road-boundary information is utilized as an inter-cell distance, and goals and start lines are positioned at the top and the bottom of the image, respectively, the optimal path finding algorithm can be exploited for optimal road boundary detection. By virtue of the parallel and analog processing of the CPPN and the optimal solution of the dynamic programming, the proposed road boundary detection algorithm is expected to have very high speed and robust processing if it is implemented into circuits. The proposed road boundary algorithm is described and simulation results are reported.

A New Circle Detection Algorithm for Pupil and Iris Segmentation from the Occluded RGB images

  • Hong Kyung-Ho
    • International Journal of Contents
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    • 제2권3호
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    • pp.22-26
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    • 2006
  • In this paper we introduce a new circle detection algorithm for occluded on/off pupil and iris boundary extraction. The proposed algorithm employs 7-step processing to detect a center and radius of occluded on/off eye images using the property of the chords. The algorithm deals with two types of occluded pupil and iris boundary information; one is composed of circle-shaped, incomplete objects, which is called occluded on iris images and the other type consists of arc objects in which circular information has partially disappeared, called occluded off iris images. This method shows that the center and radius of iris boundary can be detected from as little as one-third of the occluded on/off iris information image. It is also shown that the proposed algorithm computed the center and radius of the incomplete iris boundary information which has partially occluded and disappeared. Experimental results on RGB images and IR images show that the proposed method has encouraging performance of boundary detection for pupil and iris segmentation. The experimental results show satisfactorily the detection of circle from incomplete circle shape information which is occluded as well as the detection of pupil/iris boundary circle of the occluded on/off image.

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In-network Distributed Event Boundary Computation in Wireless Sensor Networks: Challenges, State of the art and Future Directions

  • Jabeen, Farhana;Nawaz, Sarfraz
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제7권11호
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    • pp.2804-2823
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    • 2013
  • Wireless sensor network (WSN) is a promising technology for monitoring physical phenomena at fine-grained spatial and temporal resolution. However, the typical approach of sending each sensed measurement out of the network for detailed spatial analysis of transient physical phenomena may not be an efficient or scalable solution. This paper focuses on in-network physical phenomena detection schemes, particularly the distributed computation of the boundary of physical phenomena (i.e. event), to support energy efficient spatial analysis in wireless sensor networks. In-network processing approach reduces the amount of network traffic and thus achieves network scalability and lifetime longevity. This study investigates the recent advances in distributed event detection based on in-network processing and includes a concise comparison of various existing schemes. These boundary detection schemes identify not only those sensor nodes that lie on the boundary of the physical phenomena but also the interior nodes. This constitutes an event geometry which is a basic building block of many spatial queries. In this paper, we introduce the challenges and opportunities for research in the field of in-network distributed event geometry boundary detection as well as illustrate the current status of research in this field. We also present new areas where the event geometry boundary detection can be of significant importance.

명도와 에지정보의 상관계수를 이용한 비디오샷 경계검출 (Video Shot Boundary Detection Using Correlation of Luminance and Edge Information)

  • 유헌우;정동식;나윤균
    • 제어로봇시스템학회논문지
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    • 제7권4호
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    • pp.304-308
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    • 2001
  • The increase of video data makes the demand of efficient retrieval, storing, and browsing technologies necessary. In this paper, a video segmentation method (scene change detection method, or shot boundary detection method) for the development of such systems is proposed. For abrupt cut detection, inter-frame similarities are computed using luminance and edge histograms and a cut is declared when the similarities are under th predetermined threshold values. A gradual scene change detection is based on the similarities between the current frame and the previous shot boundary frame. A correlation method is used to obtain universal threshold values, which are applied to various video data. Experimental results show that propose method provides 90% precision and 98% recall rates for abrupt cut, and 59% precision and 79% recall rates for gradual change.

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성분차 색분할과 검출마스크를 통한 실시간 교통신호등 검출과 인식 (Real time detection and recognition of traffic lights using component subtraction and detection masks)

  • 정준익;노도환
    • 대한전자공학회논문지SP
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    • 제43권2호
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    • pp.65-72
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    • 2006
  • 교통신호등 검출과 인식 시스템은 운전자에게 경고와 보조시스템으로 필요한 장치이다. 본 논문에서는 칼라 비젼시스템을 이용한 주행중 실시간 교통신호등의 검출과 인식법에 대해 제안하고 있다. 제안하는 방법은 크게 네 가지로 구분된다 유사색 환경에서도 신호등 빛 검출이 용이하도록 HSI 색 공간에서 채도와 밝기값의 차를 이용하여 신호등의 빛을 검출하는 신호등 검출, 신호등 외곽검출과 검출된 신호 빛을 바탕으로 교통신호등 외곽 후보영역 설정과 세 검출 결과를 토대로 교통신호등을 인식하는 부분이다. 주행중 영상을 비디오 카메라로 녹화하여 제안하는 방법에 적용하여 결과를 제시하였다. 녹화시 카메라의 줌기능을 이용하여 줌에 의한 입력 영상변화시에도 신호등을 검출 및 인식한 결과를 제시하였다.

저대조 혈관 조영상에서 좌심실 기능의 정량화를 위한 지식 기반의 경계선 자동검출 (Knowledge Based Automated Boundary Detection for Quantifying of Left Ventricular Function in Low Contrast Angiographic Images)

  • 전춘기;권용무
    • 대한의용생체공학회:의공학회지
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    • 제17권1호
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    • pp.109-120
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    • 1996
  • Cardiac function is evaluated quantitatively using angiographic images via the analysis of the shape change or the heart wall boundaries. To kin with, boundary defection or ESLV(End Systolic Lert Ventricular) and EDLV(End Diastolic Left Ventricular) is essential for the quantitative analysis of cardiac function. The boundary detection methods proposed in the past were almost semi-automatic. Intervention by a knowledgeable human operator was still required Of con, manual tracing of the boundaries is currently used for subsequent analysis and diagnosis. This method would not cut excessive time, labor, and subjectivity associated with manual intervention by a human operator. EDLV images have noncontiguous and ambiguous edge signal on some boundary regions. In this paper, we propose a new method for automated detection of boundaries in noncontiguous and ambiguous EDLV images. The boundary detection scheme which based on a priori knowledge information is divided into two steps. The first step is to detect the candidate edge points of EDLV using ESLV boundaries. The second step is to correct detected boundaries of EDLV using the LV shape. We developed the algorithm of modifying EDLV boundaries defined adaptive modifier. We experimented the method proposed in this paper and compared our proposed method with the manual method in detecting boundaries of EDLV. In the areas within estimated boundaries of EDLV, the percentage of error was about 1.4%. We verified the useflilness and obtained the satisfying results througll the experiments of the proposed method.

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경계 잡음 제거를 위한 2단계 경계 탐색 기반의 깊이지도 전처리 알고리즘 (Depth-map Preprocessing Algorithm Using Two Step Boundary Detection for Boundary Noise Removal)

  • 박영길;김준호;이시웅
    • 한국콘텐츠학회논문지
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    • 제14권12호
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    • pp.555-564
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    • 2014
  • DIBR(Depth Image Based Rendering)을 이용한 영상 합성 시에 발생하는 경계 잡음은 원래 전경 영역에 속하던 화소가 배경으로 흩어져 나와 생성된 잡음이며, 이는 주로 참조 영상과 깊이지도 간 경계 불일치나 참조 영상에서의 블러링 때문에 발생된다. 영상 합성 과정에서 발생된 홀 영역은 일반적으로 주위 화소를 이용하여 채워지게 되므로, 홀에 인접한 경계 잡음은 합성 영상의 화질을 저하시키는 주요 원인으로 작용한다. 이 문제를 해결하기 위해 본 논문은 깊이지도의 전처리를 이용한 새로운 경계 잡음 제거 알고리즘을 제안한다. 기존의 전처리 기법들은 경계 불일치에 따른 경계 잡음의 제거를 위해 참조 영상과 깊이지도의 경계가 일치되도록 깊이지도를 수정한다. 그러나 대부분의 기존 기법들이 신호 기울기 기반의 단순 경계 탐색 알고리즘에 기반을 두고 있어 블러링이 존재하는 경계에서는 탐색 성능의 저하가 나타난다. 제안 알고리즘은 이의 해결을 위해 2단계 경계 탐색을 이용함으로써 이행 영역과 배경 영역 간 경계를 보다 효과적으로 탐색할 수 있는 구조를 제안하였다. 실험 결과를 통해 제안 알고리즘이 기존 알고리즘에 비해 우수한 경계 잡음 제거 성능을 가짐을 보인다.

B 모드 단축 심초음파 영상의 좌심실 내벽 윤곽선 자동 검출 (Automatic Detection of Left Ventricular Endocardial Boundary on B-mode Short Axis Echocardiography)

  • 김명남;원철호;조진호
    • 전자공학회논문지B
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    • 제32B권10호
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    • pp.1294-1304
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    • 1995
  • In this paper, a method has been proposed for the fully automatic detection of left ventricular endocardial boundary in B-mode short axis echocardiography without manual intervention by human operator. The proposed method makes use of the weighted model that approximates to endocardium and incomplete edge information for echocardiography. Therefore, this method is more effective than boundary detection by only edge information. The implementation of this method is as follows. First, the proposed algorithms are used in order to detect the approximate boundary, then a weighted model with the approximate boundary is constructed. Finally, the cavity center of the left ventricle performing the Hough transform with the weighted model and edge image can be found automatically, and then the endocardial boundary using detected center, original image, weighted model, and edge image can be detected. validations of this method with experimental results on echo image of dog's heart and clinical echocardiography is verified.

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