Journal of KIISE:Computing Practices and Letters (한국정보과학회논문지:컴퓨팅의 실제 및 레터)

Korean Institute of Information Scientists and Engineers (한국정보과학회)
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TFT-LCD Defect Detection Using Double-Self Quotient Image

이중 SQI를 이용한 TFT-LCD 결함 검출

  • 박운익 (경북대학교 전자전기컴퓨터학과) ;
  • 이규봉 (경북대학교 전자전기컴퓨터학과) ;
  • 김세윤 (경북대학교 전자전기컴퓨터학과) ;
  • 박길흠 (경북대학교 전자전기컴퓨터학과)
  • Published : 2008.08.15
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Abstract

The TFT-LCD image allows non-uniform illumination variation and that is one of main difficulties of finding defect region. The SQI (self quotient image) has the HPF (high pass filter) shape and is used to reduce low frequency-lightness component. In this paper, we proposed the TFT-LCD defect-enhancement algorithm using characteristics of the SQI, that is the SQI has low-frequency flattening effect and maintains local variation. The proposed method has superior flattening effect and defect-enhancement effect compared with previous the TFT-LCD image preprocessing.

TFT-LCD영상은 불균일한 휘도 변화를 어느 정도 허용하고 있으며, 영상 전반에 걸쳐 나타나는 큰 휘도 변화는 국부적으로 주변 영역과 차이가 나는 결함 영역을 찾는데 방해가 된다. SQI(Self Quotient Image)는 얼굴 인식 분야에서 저주파에 해당하는 조명성분을 제거 하는데 사용되어 왔으며, 일종의 High Pass Filter(고주파 통과 필터) 형태이다. 본 논문에서는 SQI가 신호의 저주파 성분을 평활화 하는 효과를 가지면서 국부적인 변화를 유지하는 특성을 가지는데 착안하여, TFT-LCD영상에 존재하는 결함을 강조하는 알고리즘을 제안하였다. 제안한 방법을 기존의 TFT-LCD영상 전처리 방법들과 비교하였을 때, 평활화 효과 및 결함 영역 강조 효과가 우수함을 확인할 수 있었다.

Keywords

References

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