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

The Korean Institute of Electrical Engineers (대한전기학회)
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A Study on a New Auto-Focusing Algorthem for Digital Cameras

디지털 카메라를 위한 새로운 자동초점조절 알고리즘의 연구

  • 신승현 (서울시립大 전자전기공컴퓨터공학부) ;
  • 박중호 (서울시립대 전자전기공컴퓨터공학부) ;
  • 김근섭 (서울시립대 전자전기공컴퓨터공학부) ;
  • 조일준 (서울시립대 전자전기공컴퓨터공학부) ;
  • 김성환 (서울시립대 전자전기공컴퓨터공학부)
  • Published : 2001.09.01
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Abstract

In this paper, a new auto-focusing algorithm for digital cameras is proposed. One of the primary concerns of digital image processing is to increase image quality, and the most important factor for degrading the images is the blurring effect due to inexact focusing. The blurring effect occurs when the focusing lens is located on an unsuitable position. Therefore, focusing on an object should be proceeded before acquiring images. The proposed auto-focusing algorithm is MMDT(min-max difference threshold), and the performance of the proposed algorithm is evaluated by the use of the focus curve. It is shown that the proposed algorithm is superior to other previous auto-focusing algorithms in both the focus shape and computation time aspects. Especially, the improvement of the focus curve shape in both monotonousness and slope indicates that focusing can be done rapidly in comparison with other previous proposed algorithms.

Keywords

References

  1. M. Subbarao and A. Nikad, 'Focusing Techniques,' Optical Engineering, Vol.32, No.11, pp.2824-2836, November 1993 https://doi.org/10.1117/12.147706
  2. A. P. Pentland, 'A New Sence for Depth of Field,' IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol.PAMI-9, No.4, pp.523-531, July 1987
  3. S. K. Nayar and Y. Nakagawa, 'Shape from Focus,' IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 16, No. 8, pp.824-831, August 1994 https://doi.org/10.1109/34.308479
  4. H. Toyoda, S. Nishikawa,Y. Kitamura, M. Onishi, 'New Automatic Focusing System for Video Cameras,' IEEE Transactions on Consumer Electronics, Vol. CE-32, No. 3, pp.312-319, August 1986 https://doi.org/10.1109/TCE.1986.290049
  5. K. Hanma, M. Masuda, H. Nabeyama, and Y. Saito, 'Novel Technologies for Automatic Focusing and White Balancing of Solid State Color Video Camera,' IEEE Transactions on Consumer Electronics, Vol. CE-29, No. 3, pp.376-381, August 1983 https://doi.org/10.1109/TCE.1983.356324
  6. J. Biemond, R. L. Lagendijk, R. M. Mersereau, 'Iterative Methods for Image Deblurring,' Proceedings of IEEE, Vol. 78, No. 5, pp.856-883, May 1990 https://doi.org/10.1109/5.53403
  7. S. I. Jang et al, 'Auto-Focusing Technique and Its Hardware Implementation,' KICS vol. 20, Nol. 2, pp.502-517, 1995
  8. S. H. Lee et al, 'Auto-Focusing Algorithm for Video Camera Using the Difference of Medians', KICS vol. 23, No. 1, pp.41-50, 1998
  9. J. H. Lee, K. S. Kim, B. D. Nam, J. C. Lee, Y. M. Kwon, and H. G. Kim, 'Implementation of a Passive Automatic Focusing Algorithm for Digital Still Camera,' IEEE Transactions on Consumer Electronics, Vol. 41, No. 3, pp. 449-453, Augtst 1995 https://doi.org/10.1109/30.468047