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Applied Optics

Applied Optics


  • Vol. 26, Iss. 21 — Nov. 1, 1987
  • pp: 4612–4615

Optical/digital incoherent image processing for extended depth of field

Ting-Chung Poon and Masoud Motamedi  »View Author Affiliations

Applied Optics, Vol. 26, Issue 21, pp. 4612-4615 (1987)

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For a severely defocused incoherent system, its optical transfer function (OTF) has isolated zeros; therefore, an exact inverse filtering cannot be performed. Isolated zeros in the OTF can be avoided by choosing an annular aperture with a proper radius ratio, as the aperture can extend the depth of focus of the system. However, in the process of increasing the depth of focus of the system, this method results in a loss of image contrast. A simple hybrid optical/digital image processing system in which a TV camera device is coupled with an annular aperture is considered. Annular-pass filtering to compensate for the loss of contrast is performed by a digital computer. Experimental results are presented.

© 1987 Optical Society of America

Original Manuscript: March 26, 1987
Published: November 1, 1987

Ting-Chung Poon and Masoud Motamedi, "Optical/digital incoherent image processing for extended depth of field," Appl. Opt. 26, 4612-4615 (1987)

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  1. M. Mino, Y. Okano, “Improvement in the OTF of a Defocused Optical System Through the use of Shaded Apertures,” Appl. Opt. 10, 2219 (1971). [CrossRef] [PubMed]
  2. G. Indebetouw, H. Bai, “Imaging with Fresnel Zone Pupil Mask: Extended Depth of Field,” Appl. Opt. 23, 4299 (1984). [CrossRef] [PubMed]
  3. R. J. Pieper, A. Korpel, “Image Processing for Extended Depth of Field,” Appl. Opt. 22, 1449 (1983). [CrossRef] [PubMed]
  4. S. A. Sugimoto, Y. Ichioka, “Digital Composition of Images with Increased Depth of Focus Considering Depth Information,” Appl. Opt. 24, 2076 (1985). [CrossRef] [PubMed]
  5. G. Häusler, E. Körner, “Expansion of Depth of Focus by Image De-Puzzling,” in Proceedings, Sixth International Conference on Pattern Recognition (1982), p. 1201.
  6. G. Hausler, “A Method to Increase the Depth of Focus by Two Step Image Processing,” Opt. Commun. 6, 38 (1972). [CrossRef]
  7. G. Häusler, A. Lohmann, “Hybrid Image Processing,” Applications of Holography and Optical Data Processing, E. Maron, A. Friesem, E. Wiener-Avnear, Eds. (Pergamon, London, 1977), p. 9.
  8. W. T. Welford, “Use of Annular Apertures to Increase Focal Depth,” J. Opt. Soc. Am. 50, 749 (1960). [CrossRef]
  9. J. T. McCrickerd, “Coherent Processing and Depth of Focus of Annular Aperture Imagery,” Appl. Opt. 10, 2226 (1971). [CrossRef] [PubMed]
  10. J. Ojeda-Castaneda, P. Andres, A. Diaz, “Annular Apodizers for Low Sensitivity to Defocus and to Spherical Aberration,” Opt. Lett. 11, 487 (1986). [CrossRef] [PubMed]
  11. A. Korpel, U. Iowa; private communication.
  12. E. H. Linfoot, E. Wolf, “Diffraction Images in Systems with an Annular Aperture,” Proc. Phys. Soc. London Ser. B 66, 145 (1953). [CrossRef]
  13. A. Korpel, “Comments on ‘Diffraction-Free Beams’,”submitted to Phys. Rev. Lett.
  14. R. J. Pieper, J. Park, T.-C. Poon, “Resolution-Dependent Depth of Focus for an Incoherent Imaging System,” submitted to Appl. Opt. [PubMed]
  15. E. L. O'Neill, “Transfer Function for an Annular Aperture,” J. Opt. Soc. Am. 46, 285 (1956). [CrossRef]

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