The Journal of the Korea Contents Association (한국콘텐츠학회논문지)

The Korea Contents Association (한국콘텐츠학회)
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Image Edge Detector Based on Analog Correlator and Neighbor Pixels

아날로그 상관기와 인접픽셀 기반의 영상 윤곽선 검출기

  • 이상진 (충북대학교 전자정보대학 정보통신공학과) ;
  • 오광석 (충북대학교 전자정보대학 정보통신공학과) ;
  • 남민호 (충북대학교 전자정보대학 정보통신공학과) ;
  • 조경록 (충북대학교 전자정보대학 정보통신공학과)
  • Received : 2013.08.19
  • Accepted : 2013.10.14
  • Published : 2013.10.28
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Abstract

This paper presents a simplified hardware based edge detection circuit which is based on an analog correlator combining with the neighbor pixels in CMOS image sensor. A pixel element of the edge detector consists of an active pixel sensor and an analog correlator circuit which connects two neighbor pixels. The edge detector shares a comparator on each column that the comparator decides an edge of the target pixel with an adjustable reference voltage. The circuit detects image edge from CIS directly that reduces area and power consumption 4 times and 20%, respectively, compared with the previous works. And also it has advantage to regulate sensitivity of the edge detection because the threshold value is able to control externally. The fabricated chip has 34% of fill factor and 0.9 ${\mu}W$ of power per a pixel under 0.18 ${\mu}m$ CMOS technology.

본 논문에서는 하드웨어 기반의 영상 신호 윤곽선 검출을 위한 하드웨어기반의 알고리즘으로 CMOS 이미지 센서의 인접픽셀과 아날로그 상관기로 구성되는 윤곽선 검출기를 제안한다. 제안하는 이미지 윤곽 검출기는 각 열(column)마다 비교기를 공유하고, 비교기는 기준전압과 비교를 통해 대상 픽셀의 윤곽선 여부를 판별한다. 이미지 센서와 직접적으로 연결된 윤곽선 검출 회로는 기존의 연구와 비교하여 면적은 4배, 그리고 전력소모는 20 % 감소하는 결과를 보였다. 또한 외부에서 기준전압을 제어할 수 있어, 윤곽선 검출의 민감도를 조절하기에 유용한 장점을 가진다. 0.18 ${\mu}m$ CMOS 공정에서 제작된 칩은 34%의 fill factor를 가지며, 픽셀 당 0.9 ${\mu}W$의 전력소모를 가진다.

Keywords

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