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Applied Optics

Applied Optics


  • Vol. 38, Iss. 4 — Feb. 1, 1999
  • pp: 638–646

Filtering out contrast reversals for microscopy autofocus

Michael A. Oliva, Miguel Bravo-Zanoguera, and Jeffrey H. Price  »View Author Affiliations

Applied Optics, Vol. 38, Issue 4, pp. 638-646 (1999)

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Autofocus functions based on measurement of image resolution appear to be precise and robust for biological microscopy. However, the through-focus response of these functions previously exhibited unwanted local maxima, or side peaks. Here we report theoretical and experimental studies showing that side peaks are mainly a result of contrast reversals inherent in optical systems at mid-range frequencies. These contrast reversals are not present in frequencies near optical cutoff. Contrast reversals thus limit the lower cutoff for resolution measurement filters, whereas signal-to-noise limits the upper cutoff. These improved bandpass design criteria led to sharp, unimodal autofocus responses for all tested microscopy specimens.

© 1999 Optical Society of America

OCIS Codes
(070.2590) Fourier optics and signal processing : ABCD transforms
(110.4850) Imaging systems : Optical transfer functions
(170.5810) Medical optics and biotechnology : Scanning microscopy

Original Manuscript: May 29, 1998
Revised Manuscript: October 9, 1998
Published: February 1, 1999

Michael A. Oliva, Miguel Bravo-Zanoguera, and Jeffrey H. Price, "Filtering out contrast reversals for microscopy autofocus," Appl. Opt. 38, 638-646 (1999)

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  1. M. Bravo-Zanoguera, B. V. Massenbach, A. L. Kellner, J. H. Price, “High-performance autofocus circuit for biological microscopy,” Rev. Sci. Instruments 69, 3966–3977 (1998). [CrossRef]
  2. M. Bravo-Zanoguera, J. H. Price, “Analog autofocus circuit for scanning microscopy,” in Optical Diagnostics of Biological Fluids and Advanced Techniques in Analytical Cytology, A. V. Priezzhev, T. Asakura, R. C. Leif, eds., Proc. SPIE2982, 468–475 (1997). [CrossRef]
  3. F. R. Boddeke, L. J. van Vliet, H. Netten, I. T. Young, “Autofocusing in microscopy based on the OTF and sampling,” Bioimaging 2, 193–203 (1994). [CrossRef]
  4. J. H. Price, D. A. Gough, “Comparison of phase-contrast and fluorescence digital autofocus for scanning microscopy,” Cytometry 16, 283–297 (1994). [CrossRef] [PubMed]
  5. T. T. E. Yeo, S. H. Ong, Jayasooriah, R. Sinniah, “Autofocus for tissue microscopy,” Image Vision Comput. 11, 629–639 (1993).
  6. F. C. A. Groen, I. T. Young, G. Lighart, “A comparison of different focus functions for use in autofocus algorithms,” Cytometry 6, 81–91 (1985). [CrossRef] [PubMed]
  7. E. Krotkov, “Focusing,” Int. J. Comput. Vision 1, 223–237 (1987). [CrossRef]
  8. S. B. Marapane, M. M. Trivedi, “Experiments in active vision with real and virtual robot heads,” Appl. Intelligence 5, 237–250 (1995). [CrossRef]
  9. S. Inoué, Video Microscopy (Plenum, New York, 1986). [CrossRef]
  10. K. S. Park, R. Schowengerdt, M. A. Kaczynski, “Modulation-transfer-function analysis for sampled image systems,” Appl. Opt. 23, 2572–2582 (1984). [CrossRef] [PubMed]
  11. K. R. Castleman, Digital Image Processing (Prentice-Hall, Upper Saddle River, N. J., 1996).
  12. H. H. Hopkins, “The frequency response of a defocused optical system,” Proc. R. Soc. London Ser. A 231, 91–103 (1955). [CrossRef]
  13. M. Born, E. Wolf, Principles of Optics, 6th ed. (Pergamon, New York, 1989).
  14. J. W. Goodman, Introduction to Fourier Optics (McGraw-Hill, New York, 1988).
  15. P. A. Stokseth, “Properties of a defocused optical system,” J. Opt. Soc. Am. 59, 1314–1321 (1969). [CrossRef]
  16. D. A. Agard, “Optical sectioning microscopy: cellular architecture in three dimensions,” Ann. Rev. Biophys. Bioeng. 13, 191–219 (1984). [CrossRef]
  17. M. Françon, Progress in Microscopy (Row, Peterson, Evanston, Ill., 1961).

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