Journal of Korea Multimedia Society (한국멀티미디어학회논문지)

Korea Multimedia Society (한국멀티미디어학회)
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Sclera Segmentation for the Measurement of Conjunctival Injection

결막 충혈도 측정을 위한 공막 영상 분할

  • 배장표 (서울대학교 협동과정 바이오엔지지어링) ;
  • 김광기 (국립암센터 의공학연구과) ;
  • 정창부 (국립암센터 의공학연구과) ;
  • 양희경 (분당서울대학교병원 안과) ;
  • 황정민 (분당서울대학교병원 안과)
  • Received : 2010.01.13
  • Accepted : 2010.05.11
  • Published : 2010.08.31
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Abstract

Conjunctival injection is the initial symptom of various eye diseases such as conjunctivitis, keratitis, or uveitis. The quantification of conjunctival injection may help the diagnosis and follow-up evaluation of various eye diseases. The size of the sclera is an important factor for the quantification of conjunctival injection. However, previous manual segmentation is time-consuming.Automatic segmentation is needed to extract the objective region of interest. This paper proposed a method based on the level set algorithm to segment the sclera from an anterior eye image. The initial model of the level set algorithm is calculated using the Lab color space, k-means algorithm and the geometric information. The level set algorithm was applied to the images in which the valley between the eyeball and skin was enhanced using the hessian analysis. This algorithm was tested with 52 images of the anterior eye segment. Results showed that the proposed method performs better than those with the level set algorithm using an arbitrary circle, or the region growing algorithm with color information. The proposed method for the segmentation of sclera may become an important component for the objective measurement of the conjunctival injection.

결막 충혈은 결막염, 각막염, 포도막염 등의 안과질환의 초기 증세로서 정량적으로 평가할 수 있다면 진단과 경과 관찰에 도움이 된다. 충혈의 정량화에서 공막의 크기는 중요한 지표이지만 기존의 공막 분할 방법이 정확하지 않기 때문에 수동으로 분할하고 있다. 본 논문에서는 충혈의 정량화를 위하여 level set 방법을 이용한 공막 분할 알고리즘을 제안한다. Level set의 초기 모델은 Lab 색상 모드와 k-means 알고리즘, 기하학적인 정보를 이용하여 지정된다. 헤이시안(hessian) 분석으로 공막과 피부 사이의 골을 향상시킨 영상에 level set을 적용하였다. 제안 방법의 성능 측정을 위하여 52개의 전안부 영상에 대하여 실험하였다. 실험 결과, 제안 방법이 화소값만 이용하는 region growing이나 level set의 초기 모델로 임의의 원을 이용하는 방법보다 성능이 우수하였다. 이 논문에서 제안한 공막 분할 방법은 객관적인 충혈도 측정에서 중요한 요소 기술의 역할을 할 것이다.

Keywords

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