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Proceedings Paper

Estimation of out-of-focus blur and its effectiveness for deblurring
Author(s): Naoki Saitoh; Kenro Kuroki; Kenji Kurosawa
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Paper Abstract

We have studied the use of point spread function (PSF) calculated by the wave optics for restoration of out-of- focused images. According to the theory, PSF and its Fourier transform OTF depend only on the defocus quantity (Delta) which can be calculated by using physical quantities of a lens. It is recognized that large objects in out-of-focused images can be restored well by using calculated PSF or OTF when a diaphragm is circular and (Delta) is estimated adequately. However details can not be restored well especially when (Delta) is large. Difference is recognized between PSF based on the geometrical optics and PSF based on the wave optics. It is recognized that images obtained by using PSF calculated by the wave optics are better in sharpness than by using PSF calculated by the geometrical optics. Such difference becomes larger as (Delta) becomes smaller. In the case that the diaphragm differs from a circular disc such as home video cameras, it is important to take the diaphragm form into account.

Paper Details

Date Published: 19 February 1997
PDF: 8 pages
Proc. SPIE 2942, Investigative Image Processing, (19 February 1997); doi: 10.1117/12.267165
Show Author Affiliations
Naoki Saitoh, National Research Institute of Police Science (Japan)
Kenro Kuroki, National Research Institute of Police Science (Japan)
Kenji Kurosawa, National Research Institute of Police Science (Japan)


Published in SPIE Proceedings Vol. 2942:
Investigative Image Processing
Leonid I. Rudin; Simon K. Bramble, Editor(s)

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