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Pattern Elimination Method Based on Perspective Transform for Defect Detection of TFT-LCD

TFT-LCD의 결함 검출을 위한 원근 변환 기반의 패턴 제거 방법

  • 이준재 (계명대학교 게임모바일콘텐츠학과) ;
  • 이광호 (경일대학교 전자공학과) ;
  • 정창도 (타이코에이엠피 연구소) ;
  • 박길흠 (경북대학교 전자전기공학부) ;
  • 박윤범 (서원대학교 수학교육학과) ;
  • 이병국 (동서대학교 컴퓨터정보공학부)
  • Received : 2011.12.06
  • Accepted : 2012.04.30
  • Published : 2012.06.30

Abstract

Defects of TFT-LCD is detected by thresholding the difference image between the input image and template one because LCD panel has its inherent patterns. However, the pitch corresponding to pattern period is gradually changed according to the distance from the center of camera due to geometric distortion of camera characteristics. This paper presents a method to detect defects through comparing the pitch area with neighbor pitch areas where the perspective transform is performed with the extracted features to correct the distortion. The experimental results show that the performance of the proposed method is very effective for real data.

TFT-LCD의 결함은 LCD 패널 자체에 존재하는 패턴으로 인해 원본영상과 입력영상 간의 차영상에 문턱치를 적용하여 검출한다. 그러나 카메라의 특성에 기인한 기하학적인 왜곡에 의해, 패널의 패턴 주기에 해당하는 피치가 영상의 중심에서 멀어질수록 심하게 달라진다. 본 논문에서는 주어진 피치영역의 상하좌우 주변영역과의 비교에 기반한 검출을 제안한다. 이때, 왜곡 보정을 위해 피치계산을 위한 특징점을 추출하고 원근변환을 수행한다. 현장 데이터에 대한 실험을 통해 제안방법의 우수성을 입증한다.

Keywords

References

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