• 제목/요약/키워드: Segment Algorithm

검색결과 585건 처리시간 0.034초

웨이브렛 변환을 이용한 스트레스 심전도 분석 알고리즘의 개발 (Development of a Stress ECG Analysis Algorithm Using Wavelet Transform)

  • 이경중;박광리
    • 대한의용생체공학회:의공학회지
    • /
    • 제19권3호
    • /
    • pp.269-278
    • /
    • 1998
  • 본 논문에서는 스트레스 심전도를 분석함에 있어서 가장 중요한 파라미터인 ST 세그먼트를 측정하기 위해서 웨이브렛 변환을 이용하여 Wavelet Adaptive Filter(WAF)와 QRS콤플렉스 검출 알고리즘을 설계하였다. WAF는 웨이브렛 변환부와 적응필터부로 구성되어 있으며, 웨이브렛 변환부에서는 웨이브렛 함수를 이용하여 입력되는 심전도 신호를 저주파 대역과 고주파 대역으로 각각 j=-7레벨까지 분할하고, 적응필터부에서는 웨이브렛 변환에 의해 분할된 신호중 j=-7레벨의 저주파 대역 신호를 주입력으로 사용하여 필터링 한다. QRS 콤플레스는 합산신호를 구성한 후 문턱치를 RR간격에 변화에 따라 변화시키면서 검출하였으며, 합산신호는 웨이브렛 변환에 의해 QRS 콤플렉스의 주파수 성분이 포함되어 있는 고주파 대역의 신호를 더하여 구성하였다. WAF는 표준 필터와 일반적인 적응필터와 성능을 비교하였으며, 잡음제거 특성과 신호왜곡도 측면에서 비교필터에 비해 우수한 성능을 보였다. QRS 콤플렉스 검출성능을 평가하기 위해서 MIT/BIH데이터베이스를 이용하여 기존의 QRS 검출 알고리즘들의 검출 방법과 비교하였으며, 웨이브렛에 의한 합산신호를 이용할 경우에 99..67%로써 더 좋은 검출성능을 보였다. 또한 측정된 ST세그먼트의 정확도를 비교.평가를 위하여 European ST-T 데이터베이스와 실제 임상데이터를 이용하였으며 심박수의 변화에 따라 적응적으로 ST세그먼트를 측정할 수 있었다.

  • PDF

적응공명이론에 의한 자동 부분형상 인식시스템 (Automatic partial shape recognition system using adaptive resonance theory)

  • 박영태;양진성
    • 전자공학회논문지B
    • /
    • 제33B권3호
    • /
    • pp.79-87
    • /
    • 1996
  • A new method for recognizing and locating partially occluded or overlapped two-dimensional objects regardless of their size, translation, and rotation, is presented. Dominant points approximating occuluding contoures of objects are generated by finding local maxima of smoothed k-cosine function, and then used to guide the contour segment matching procedure. Primitives between the dominant points are produced by projecting the local contours onto the line between the dominant points. Robust classification of primitives. Which is crucial for reliable partial shape matching, is performed using adaptive resonance theory (ART2). The matched primitives having similar scale factors and rotation angles are detected in the hough space to identify the presence of the given model in the object scene. Finally the translation vector is estimated by minimizing the mean squred error of the matched contur segment pairs. This model-based matching algorithm may be used in diveerse factory automation applications since models can be added or changed simply by training ART2 adaptively without modifying the matching algorithm.

  • PDF

동적 세그먼트 기반 PCB 패턴의 적응 검사 알고리즘 (An Adaptive and Robust Inspection Algorithm of PCB Patterns Based on Movable Segments)

  • 문순환;김경범
    • 한국정밀공학회지
    • /
    • 제23권3호
    • /
    • pp.102-109
    • /
    • 2006
  • Several methods for PCB pattern inspection have been tried to detect fine detects in pad contours, but their low detection accuracy results from pattern variations originating from etching, printing and handling processes. The adaptive inspection algorithm has been newly proposed to extract minute defects based on movable segments. With gerber master images of PCB, vertex extractions of a pad boundary are made and then a lot of segments are constructed in master data. The pad boundary is composed of segment units. The proposed method moves these segments to optimal directions of a pad boundary and so adaptively matches segments to pad contours of inspected images, irrespectively of various pattern variations. It makes a fast, accurate and reliable inspection of PCB patterns. Its performances are also evaluated with several images.

자율주행차량의 실시간 강건한 주행을 위한 연구 (Study on Robust Driving for Autonomous Vehicle in Real-Time)

  • 이대은;김정훈;김영배
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2004년도 추계학술대회 논문집
    • /
    • pp.908-911
    • /
    • 2004
  • In this paper, we describe a robust image processing algorithm to recognize the road lane in real-time. For the real-time processing, a detection area is decided by a lane segment of a previous frame and edges are detected on the basis of the lane width. For the robust driving, the global threshold with the Otsu algorithm is used to get a binary image in a frame. Therefore, reliable edges are obtained from the algorithms suggested in this paper in a short time. Lastly, the lane segment is found by hough transform. We made a RC(Radio Control) car equipped with a vision system and verified these algorithms using the RC Car.

  • PDF

허프변환과 차선모델을 이용한 효과적인 차선검출에 관한 연구 (Study on Effective Lane Detection Using Hough Transform and Lane Model)

  • 김기석;이진욱;조재수
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
    • /
    • pp.34-36
    • /
    • 2009
  • This paper proposes an effective lane detection algorithm using hugh transform and lane model. The proposed lane detection algorithm includes two major components, i.e., lane marks segmentation and an exact lane extraction using a novel postprocessing technique. The first step is to segment lane marks from background images using HSV color model. Then, a novel postprocessing is used to detect an exact lane using Hugh transform and lane models(linear and curved lane models). The postprocessing consists of three parts, i.e, thinning process, Hugh Transform and filtering process. We divide input image into three regions of interests(ROIs). Based on lane curve function(LCF), we can detect an exact lane from various extracted lane lines. The lane models(linear and curved lane mode]) are used in order to judge whether each lane segment is fit or not in each ROIs. Experimental results show that the proposed scheme is very effective in lane detection.

  • PDF

레벨셋 기반 꽃 분할을 위한 노이즈 제거 (Noise Removal for Level Set based Flower Segmentation)

  • 박상철;오강한;나인섭;김수형;양형정;이귀상
    • 스마트미디어저널
    • /
    • 제1권2호
    • /
    • pp.34-39
    • /
    • 2012
  • 본 연구에서는 노이즈를 제거하고 자연 영상에서 자동으로 꽃을 분할하는 후처리방법을 제시한다. 레벨 셋 알고리즘을 이용한 자연영상 꽃 분할에서는 레벨 셋이 에지 정보에만 의존하기 때문에 기대하지 않았던 분리된 노이즈들이 발생한다. 실험 결과는 제안 방법이 꽃 영역과 배경 영역의 많은 노이즈를 성공적으로 제거하였음을 보여준다.

  • PDF

반도체 웨이퍼 ID 인식을 위한 다중템플릿형 영상분할 알고리즘 개발 (Development of a Multi-template type Image Segmentation Algorithm for the Recognition of Semiconductor Wafer ID)

  • 안인모
    • 전기학회논문지P
    • /
    • 제55권4호
    • /
    • pp.167-175
    • /
    • 2006
  • This paper presents a method to segment semiconductor wafer ID on poor quality images. The method is based on multiple templates and normalized gray-level correlation (NGC) method. If the lighting condition is not so good and hence, we can not control the image quality, target image to be inspected presents poor quality ID and it is not easy to identify and then recognize the ID characters. Conventional several method to segment the interesting ID regions fails on the bad quality images. In this paper, we propose a multiple template method, which uses combinational relation of multiple templates from model templates to match several characters of the inspection images. To find out the optimal solution of multiple template model in ID regions, we introduce newly-developed snake algorithm. Experimental results using images from real FA environment are presented.

회로 결선도 분할을 위해 점진적 병합을 이용한 선형배열 (Linear Ordering with Incremental Merging for Circuit Netlist Partitioning)

  • 성광수
    • 전자공학회논문지C
    • /
    • 제35C권9호
    • /
    • pp.21-28
    • /
    • 1998
  • 본 논문에서는 회로결선도 분할을 위해 LIME이라는 효과적인 선형배열 알고리즘을 제안한다. LIME은 제안된 비용함수를 이용해 하나의 세그먼트가 남을 때까지 두 개의 세그먼트를 병합한다. 마지막에 남은 하나의 세그먼트가 선형배열에 해당한다. LIME은 회로 결선도의 성긴 특징을 이용하므로 상당히 빠르게 수행된다. 제안된 알고리즘은 기존 방법보다 전형배열을 만드는데 약 8배 빠른 수행 속도를 보이며, 이를 이용한 회로 결선도 분할 결과도 스케일드 비용 면에서 약 17% 향상되었다.

  • PDF

변이별 정합 척도 분포를 이용한 선소의 정합 (Segment matching using matching measure distribution over disparities)

  • 강창순;남기곤
    • 전자공학회논문지S
    • /
    • 제34S권3호
    • /
    • pp.74-83
    • /
    • 1997
  • In this paper, a new stereo matching algorithm is proposed which uses th econstrainted optimization technique and the matching measures between the segments extracted from zero-crossing edges. The initial matching measures and average disparities are calculated by the features of segments on the searching window of the left and right images. The matching measure is calculated by applying an exponential function using the differences of slope, overlapped length and intensity. The coherency constraint is that neighbouring image points corresponding to the same object should have nearly the same disparities. The matching measures are iteratively updated by applying the coherency constraint. Simulation results on various images show that the proposed algorithm more acculately extracts the segment disparity.

  • PDF

MAP 추정 알고리즘에 의한 레이더 영상에서 도로검출 (Detection of Road Features Using MAP Estimation Algorithm In Radar Images)

  • 김순백;이수흠;김두영
    • 융합신호처리학회 학술대회논문집
    • /
    • 한국신호처리시스템학회 2003년도 하계학술대회 논문집
    • /
    • pp.62-65
    • /
    • 2003
  • We propose an algorithm for almost unsupervised detection of linear structures, in particular, axes in road network and river, as seen in synthetics aperture radar (SAR) images. The first is local step and used to extract linear features from the speckle radar image, which are treated as road segment candidates. We present two local line detectors as well as a method for fusing information from these detectors. The second is global step, we identify the real roads among the segment candidates by defining a Markov random field (MRF) on a set of segments, which introduces contextual knowledge about the shape of road objects.

  • PDF