The Transactions of the Korean Institute of Electrical Engineers D (대한전기학회논문지:시스템및제어부문D)

The Korean Institute of Electrical Engineers (대한전기학회)
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A Design of Real-time Automatic Focusing System for Digital Still Camera Using the Passive Sensor Error Minimization

수동 센서의 오차 최소화를 이용한 실시간 DSC 자동초점 시스템 설계

  • 김근섭 (삼선테크윈 광디지털 시스템 개발 2 Unit) ;
  • 김덕영 (부천대학 전자과) ;
  • 김성환 (서울시립대 전자전기과학부)
  • Published : 2002.05.01
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Abstract

In this paper, the implementation of a new AF(Automatic Focusing) system for a digital still camera is introduced. The proposed system operates in real-time while adjusting focus after the measurement of distance to an object using a passive sensor, which is different from a typical method. In audition, measurement errors were minimized by using the data acquired empirically, and the optimal measuring time was obtained using EV(Exposure Value) which is calculated from CCD luminance signal. Moreover, this system adopted an auxiliary light source for focusing in absolute dark conditions, which is very hard for CCD image Processing. Since this is an open-loop system adjusting focus immediately after the distance measurement, it guarantees real-time operation. The performance of this new AF system was verified by comparing the focusing value curve obtained from AF experiment with the one from the measurement by MF(Manual-Focusing). In both case, edge detector was used for various objects and backgrounds.

Keywords

References

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