Journal of the Institute of Electronics Engineers of Korea SP (대한전자공학회논문지SP)

The Institute of Electronics and Information Engineers (대한전자공학회)
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Subject Region-Based Auto-Focusing Algorithm Using Noise Robust Focus Measure

잡음에 강인한 초점 값을 이용한 피사체 중심의 자동초점 알고리듬

  • Jeon, Jae-Hwan (Dept. of Image Engineering. Graduate School of Advanced Image Science, Multimedia, and Film, Chung-Ang University) ;
  • Yoon, In-Hye (Dept. of Image Engineering. Graduate School of Advanced Image Science, Multimedia, and Film, Chung-Ang University) ;
  • Lee, Jin-Hee (Dept. of Image Engineering. Graduate School of Advanced Image Science, Multimedia, and Film, Chung-Ang University) ;
  • Paik, Joon-Ki (Dept. of Image Engineering. Graduate School of Advanced Image Science, Multimedia, and Film, Chung-Ang University)
  • 전재환 (중앙대학교 첨단영상 대학원) ;
  • 윤인혜 (중앙대학교 첨단영상 대학원) ;
  • 이진희 (중앙대학교 첨단영상 대학원) ;
  • 백준기 (중앙대학교 첨단영상 대학원)
  • Received : 2010.08.29
  • Accepted : 2010.11.30
  • Published : 2011.03.25
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Abstract

In this paper we present subject region-based auto-focusing algorithm using noise robust focus measure. The proposed algorithm automatically estimates the main subject using entropy and solves the traditional problems with a subject position or high frequency component of background image. We also propose a new focus measure by analyzing the discrete cosine transform coefficients. Experimental results show that the proposed method is more robust to Gaussian and impulse noises than the traditional methods. The proposed algorithm can be applied to Pan-tilt-zoom (PTZ) cameras in the intelligent video surveillance system.

본 논문은 잡음에 강인한 초점 값을 이용한 피사체 중심의 자동초점 알고리듬을 제안한다. 제안된 방법은 영상의 엔트로피를 이용하여 피사체가 존재하는 영역을 자동으로 추정함으로써, 배경에 의해 잘못된 자동초점 결과를 얻는 문제점을 개선하였다. 또한 이산 코사인 변환 계수를 분석하여 새로운 초점 값 계산 방법을 제안하였고, 실험결과를 통해 기존의 알고리듬에 비해 제안된 방법이 가우시안 잡음과 임펄스 잡음이 있는 경우에도 초점 값 특성이 강인함을 검증하였다. 제안하는 자동초점 알고리듬은 지능형 감시 시스템의 팬-틸트-줌 카메라 등에 적용 가능하다.

Keywords

References

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