Abstract

A simple image-subtraction technique for further enhancement of the visibility depth in polarized imaging of surfaces immersed in scattering media is proposed and assessed. The technique is based on active illumination with circular or linear polarization states and image detection in the original and the opposite, or orthogonal, states. Contrast enhancement is achieved by subtraction of a fraction of the image recorded in the original state from that recorded in the opposite state. Results demonstrating the effectiveness of this method, obtained with Monte Carlo techniques, show that the visibility depth can be increased by as much as a mean free path. The results obtained are compared with those obtained by use of two alternative methods.

© 2000 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. E. P. Zege, A. P. Ivanov, I. L. Katsev, Image Transfer through a Scattering Medium (Springer-Verlag, Berlin, 1991).
    [CrossRef]
  2. P. Naulleau, D. Dilworth, “Motion-resolved imaging of moving objects embedded within scattering media by the use of time-gated speckle analysis,” Appl. Opt. 35, 5251–5257 (1996).
    [CrossRef] [PubMed]
  3. B. Chance, R. R. Alfano, eds., Optical Tomography, Photon Migration, and Spectroscopy of Tissue And Model Media: Theory, Human Studies, and Instrumentation, Proc. SPIE2389 (1995).
  4. G. E. Anderson, F. Liu, R. R. Alfano, “Microscope imaging through highly scattering media,” Opt. Lett. 19, 981–983 (1994).
    [CrossRef] [PubMed]
  5. S. R. Arridge, J. C. Hebden, “Optical imaging in medicine II: modelling and reconstruction techniques,” Phys. Med. Biol. 42, 841–853 (1997).
    [CrossRef] [PubMed]
  6. S. Fantini, S. A. Walker, M. A. Franceschini, M. Kaschke, P. M. Schlag, K. T. Moesta, “Assessment of the size, position, and optical properties of breast tumors in vivo by noninvasive optical methods,“ Appl. Opt. 37, 1982–1989 (1998).
  7. S. L. Jacques, K. Lee, “Imaging tissues with a polarized light video camera,” in 1999 International Conference on Biomedical Optics, Q. Luo, B. Chance, L. V. Wang, S. L. Jacques, eds., Proc. SPIE3863, 68–74 (1999); S. L. Jacques, J. R. Roman, K. Lee, “Imaging superficial tissues with polarized light,” Lasers Surg. Med. 26, 119–129 (2000).
    [CrossRef] [PubMed]
  8. J. S. Jaffe, K. D. Moore, D. Zawada, B. L. Ochoa, E. Zege, “Underwater optical imaging: new hardware and software,” Sea Technol. 39, 70–74 (1998).
  9. R. X. Li, H. H. Li, W. H. Zou, R. G. Smith, T. A. Smith, T. A. Curran, “Quantitative photogrammatic analysis of digital underwater video imagery,” IEEE J. Ocean. Eng. 22, 364–375 (1997).
    [CrossRef]
  10. S. M. Christie, F. Kvasnik, “Contrast enhancement of underwater images with coherent optical image processors,” Appl. Opt. 35, 817–825 (1996).
    [CrossRef] [PubMed]
  11. X. M. Lui, J. L. He, X. H. Sun, M. D. Zhang, “Instrument for collimating and expanding Gaussian beams for underwater laser imaging systems,” Opt. Eng. 37, 2467–2471 (1998).
    [CrossRef]
  12. G. D. Gilbert, J. C. Pernicka, “Improvement of underwater visibility by reduction of backscatter with a circular polarization technique,” Appl. Opt. 6, 741–746 (1967).
    [CrossRef] [PubMed]
  13. J. Cariou, B. Le Jeune, J. Lotrian, Y. Guern, “Polarization effects of seawater and underwater targets,” Appl. Opt. 29, 1689–1695 (1990).
    [CrossRef] [PubMed]
  14. G. R. Fournier, D. Bonnier, J. L. Forand, P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
    [CrossRef]
  15. P. C. Y. Chang, J. G. Walker, K. I. Hopcraft, B. Ablitt, E. Jakeman, “Polarization discrimination for active imaging in scattering media,” Opt. Commun. 159, 1–6 (1999).
    [CrossRef]
  16. K. Turpin, J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, B. Ablitt, E. Jakeman, “The influence of particle size in active polarization imaging in scattering media,” Opt. Commun. 168, 325–335 (1999).
    [CrossRef]
  17. G. N. Plass, G. W. Kattawar, “Monte Carlo calculations of light scattering from clouds,” Appl. Opt. 7, 415–419 (1968).
    [CrossRef] [PubMed]
  18. G. N. Plass, G. W. Kattawar, “Reflection of light pulses from clouds,” Appl. Opt. 10, 2304–2310 (1971); E. A. Bucher, “Computer simulation of light pulse propagation for communication through thick clouds,” Appl. Opt. 12, 2391–2400 (1973).
    [CrossRef] [PubMed]
  19. B. Maheu, J.-P. Briton, G. Gouesbet, “Four-flux model and a Monte Carlo code: comparisons between two simple, complementary tools for multiple scattering calculations,” Appl. Opt. 28, 22–24 (1989); J.-P. Briton, B. Maheu, G. Gréhan, G. Gouesbet, “Monte Carlo simulation of multiple scattering in arbitrary 3-D geometry,” Part. Part. Syst. Charact. 9, 52–58 (1992).
    [CrossRef] [PubMed]
  20. P. Bruscaglioni, P. Donelli, A. Ismaelli, G. Zaccanti, “A numerical procedure for calculating the effect of a turbid medium on the MTF of an optical system,” J. Mod. Opt. 38, 129–142 (1991); P. Donelli, P. Bruscaglioni, A. Ismaelli, G. Zaccanti, “Experimental validation of a Monte Carlo procedure for the evaluation of the effect of a turbid medium on the point spread function of an optical system,” J. Mod. Opt. 38, 2189–2201 (1991).
    [CrossRef]
  21. G. W. Kattawar, G. N. Plass, “Radiance and polarization of multiple scattered light from haze and clouds,” Appl. Opt. 7, 1519–1527 (1968); G. W. Kattawar, G. N. Plass, “Degree and direction of polarization of multiple scattered light. 1. Homogeneous cloud layers,” Appl. Opt. 11, 2851–2865 (1972).
    [CrossRef] [PubMed]
  22. T. Aruga, T. Igarashi, “Narrow beam light transfer in small particles: image blurring and depolarization,” Appl. Opt. 20, 2698–2705 (1981); erratum, 20, 3831 (1981).
  23. J. M. Schmitt, A. H. Gandjbakhche, R. F. Bonner, “Use of polarized light to discriminate short-path photons in a multiply scattering medium,” Appl. Opt. 31, 6535–6546 (1992).
    [CrossRef] [PubMed]
  24. P. Bruscaglioni, G. Zaccanti, Q. Wei, “Transmission of a pulsed polarized light beam through thick turbid media: numerical results,” Appl. Opt. 32, 6142–6150 (1993).
    [CrossRef] [PubMed]
  25. D. Bicout, C. Brosseau, A. S. Martinez, J. M. Schmitt, “Depolarization of multiply scattered waves by spherical diffusers: influence of the size parameter,” Phys. Rev. E 49, 1767–1770 (1994); A. S. Martinez, R. Maynard, “Faraday effect and multiple scattering of light,” Phys. Rev. B 50, 3714–3732 (1994).
    [CrossRef]
  26. O. Fischer, Th. Henning, H. W. Yorke, “Simulation of polarization maps. I. Protostellar envelopes,” Astron. Astrophys. 284, 187–209 (1994).
  27. W. J. Henney, D. J. Axon, “Polarization profiles of scattered emission lines. III. Effects of multiple scattering and non-Rayleigh phase functions,” Astrophys. J. 454, 233–253 (1995).
    [CrossRef]
  28. S. Bianchi, A. Ferrara, C. Giovanardi, “Monte Carlo simulations of dusty spiral galaxies: extinction and polarization properties,” Astrophys. J. 465, 127–144 (1996).
    [CrossRef]
  29. H. C. van de Hulst, Light Scattering by Small Particles (Dover, New York, 1981).
  30. M. I. Mishchenko, J. W. Hovenier, L. D. Travis, eds., Light Scattering by Nonspherical Particles (Academic, San Diego, Calif., 2000).
  31. S. Chandrasekhar, Radiative Transfer (Dover, New York, 1960).
  32. P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Properties of a polarized light-beam multiply scattered by a Rayleigh medium,” in Light Scattering from Microstructures, F. Moreno, F. Gonzalez, eds. (Springer-Verlag, Berlin, 2000).
  33. P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Polarization properties of light multiply scattered by non-spherical Rayleigh particles,” Waves Random Media 9, 415–426 (1999).
    [CrossRef]
  34. K. L. Coulson, J. V. Dave, Z. Sekera, Tables Related to Radiation Emerging from a Planetary Atmosphere with Rayleigh Scattering (University of California, Berkeley, Berkeley, Calif., 1960).
  35. K. F. Evans, G. L. Stephens, “A new polarized atmospheric radiative transfer model,” J. Quant. Spectrosc. Radiat. Transfer 46, 413–423 (1991).
    [CrossRef]
  36. M. I. Mishchenko, “The fast invariant imbedding method for polarized light: computational aspects and numerical results for Rayleigh scattering,” J. Quant. Spectrosc. Radiat. Transfer 43, 163–171 (1990).
    [CrossRef]
  37. J. E. Hansen, L. D. Travis, “Light scattering in planetary atmospheres,” Space Sci. Rev. 16, 527–610 (1974).
    [CrossRef]
  38. H. C. van de Hulst, Multiple Light Scattering (Academic, San Diego, Calif.,1980), Vol. 1.
  39. C. V. M. van der Mee, “Eigenvalue criterion for polarization matrices,” J. Math. Phys. 34, 5072–5088 (1993).
    [CrossRef]
  40. G. D. Lewis, D. L. Jordan, P. J. Roberts, “Backscattering target detection in a turbid medium using polarization discrimination,” Appl. Opt. 38, 3937–3944 (1999).
    [CrossRef]
  41. M. Barrow, “Imaging through obscurants,” Ph.D. dissertation (University of London, London, 1996).
  42. R. C. Gonzalez, R. E. Woods, Digital Image Processing, 3rd ed. (Addison-Wesley, New York, 1992).

1999 (4)

P. C. Y. Chang, J. G. Walker, K. I. Hopcraft, B. Ablitt, E. Jakeman, “Polarization discrimination for active imaging in scattering media,” Opt. Commun. 159, 1–6 (1999).
[CrossRef]

K. Turpin, J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, B. Ablitt, E. Jakeman, “The influence of particle size in active polarization imaging in scattering media,” Opt. Commun. 168, 325–335 (1999).
[CrossRef]

P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Polarization properties of light multiply scattered by non-spherical Rayleigh particles,” Waves Random Media 9, 415–426 (1999).
[CrossRef]

G. D. Lewis, D. L. Jordan, P. J. Roberts, “Backscattering target detection in a turbid medium using polarization discrimination,” Appl. Opt. 38, 3937–3944 (1999).
[CrossRef]

1998 (3)

S. Fantini, S. A. Walker, M. A. Franceschini, M. Kaschke, P. M. Schlag, K. T. Moesta, “Assessment of the size, position, and optical properties of breast tumors in vivo by noninvasive optical methods,“ Appl. Opt. 37, 1982–1989 (1998).

J. S. Jaffe, K. D. Moore, D. Zawada, B. L. Ochoa, E. Zege, “Underwater optical imaging: new hardware and software,” Sea Technol. 39, 70–74 (1998).

X. M. Lui, J. L. He, X. H. Sun, M. D. Zhang, “Instrument for collimating and expanding Gaussian beams for underwater laser imaging systems,” Opt. Eng. 37, 2467–2471 (1998).
[CrossRef]

1997 (2)

R. X. Li, H. H. Li, W. H. Zou, R. G. Smith, T. A. Smith, T. A. Curran, “Quantitative photogrammatic analysis of digital underwater video imagery,” IEEE J. Ocean. Eng. 22, 364–375 (1997).
[CrossRef]

S. R. Arridge, J. C. Hebden, “Optical imaging in medicine II: modelling and reconstruction techniques,” Phys. Med. Biol. 42, 841–853 (1997).
[CrossRef] [PubMed]

1996 (3)

1995 (1)

W. J. Henney, D. J. Axon, “Polarization profiles of scattered emission lines. III. Effects of multiple scattering and non-Rayleigh phase functions,” Astrophys. J. 454, 233–253 (1995).
[CrossRef]

1994 (3)

D. Bicout, C. Brosseau, A. S. Martinez, J. M. Schmitt, “Depolarization of multiply scattered waves by spherical diffusers: influence of the size parameter,” Phys. Rev. E 49, 1767–1770 (1994); A. S. Martinez, R. Maynard, “Faraday effect and multiple scattering of light,” Phys. Rev. B 50, 3714–3732 (1994).
[CrossRef]

O. Fischer, Th. Henning, H. W. Yorke, “Simulation of polarization maps. I. Protostellar envelopes,” Astron. Astrophys. 284, 187–209 (1994).

G. E. Anderson, F. Liu, R. R. Alfano, “Microscope imaging through highly scattering media,” Opt. Lett. 19, 981–983 (1994).
[CrossRef] [PubMed]

1993 (3)

G. R. Fournier, D. Bonnier, J. L. Forand, P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
[CrossRef]

P. Bruscaglioni, G. Zaccanti, Q. Wei, “Transmission of a pulsed polarized light beam through thick turbid media: numerical results,” Appl. Opt. 32, 6142–6150 (1993).
[CrossRef] [PubMed]

C. V. M. van der Mee, “Eigenvalue criterion for polarization matrices,” J. Math. Phys. 34, 5072–5088 (1993).
[CrossRef]

1992 (1)

1991 (2)

K. F. Evans, G. L. Stephens, “A new polarized atmospheric radiative transfer model,” J. Quant. Spectrosc. Radiat. Transfer 46, 413–423 (1991).
[CrossRef]

P. Bruscaglioni, P. Donelli, A. Ismaelli, G. Zaccanti, “A numerical procedure for calculating the effect of a turbid medium on the MTF of an optical system,” J. Mod. Opt. 38, 129–142 (1991); P. Donelli, P. Bruscaglioni, A. Ismaelli, G. Zaccanti, “Experimental validation of a Monte Carlo procedure for the evaluation of the effect of a turbid medium on the point spread function of an optical system,” J. Mod. Opt. 38, 2189–2201 (1991).
[CrossRef]

1990 (2)

J. Cariou, B. Le Jeune, J. Lotrian, Y. Guern, “Polarization effects of seawater and underwater targets,” Appl. Opt. 29, 1689–1695 (1990).
[CrossRef] [PubMed]

M. I. Mishchenko, “The fast invariant imbedding method for polarized light: computational aspects and numerical results for Rayleigh scattering,” J. Quant. Spectrosc. Radiat. Transfer 43, 163–171 (1990).
[CrossRef]

1989 (1)

1981 (1)

1974 (1)

J. E. Hansen, L. D. Travis, “Light scattering in planetary atmospheres,” Space Sci. Rev. 16, 527–610 (1974).
[CrossRef]

1971 (1)

1968 (2)

1967 (1)

Ablitt, B.

P. C. Y. Chang, J. G. Walker, K. I. Hopcraft, B. Ablitt, E. Jakeman, “Polarization discrimination for active imaging in scattering media,” Opt. Commun. 159, 1–6 (1999).
[CrossRef]

K. Turpin, J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, B. Ablitt, E. Jakeman, “The influence of particle size in active polarization imaging in scattering media,” Opt. Commun. 168, 325–335 (1999).
[CrossRef]

Alfano, R. R.

Anderson, G. E.

Arridge, S. R.

S. R. Arridge, J. C. Hebden, “Optical imaging in medicine II: modelling and reconstruction techniques,” Phys. Med. Biol. 42, 841–853 (1997).
[CrossRef] [PubMed]

Aruga, T.

Axon, D. J.

W. J. Henney, D. J. Axon, “Polarization profiles of scattered emission lines. III. Effects of multiple scattering and non-Rayleigh phase functions,” Astrophys. J. 454, 233–253 (1995).
[CrossRef]

Barrow, M.

M. Barrow, “Imaging through obscurants,” Ph.D. dissertation (University of London, London, 1996).

Bianchi, S.

S. Bianchi, A. Ferrara, C. Giovanardi, “Monte Carlo simulations of dusty spiral galaxies: extinction and polarization properties,” Astrophys. J. 465, 127–144 (1996).
[CrossRef]

Bicout, D.

D. Bicout, C. Brosseau, A. S. Martinez, J. M. Schmitt, “Depolarization of multiply scattered waves by spherical diffusers: influence of the size parameter,” Phys. Rev. E 49, 1767–1770 (1994); A. S. Martinez, R. Maynard, “Faraday effect and multiple scattering of light,” Phys. Rev. B 50, 3714–3732 (1994).
[CrossRef]

Bonner, R. F.

Bonnier, D.

G. R. Fournier, D. Bonnier, J. L. Forand, P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
[CrossRef]

Briton, J.-P.

Brosseau, C.

D. Bicout, C. Brosseau, A. S. Martinez, J. M. Schmitt, “Depolarization of multiply scattered waves by spherical diffusers: influence of the size parameter,” Phys. Rev. E 49, 1767–1770 (1994); A. S. Martinez, R. Maynard, “Faraday effect and multiple scattering of light,” Phys. Rev. B 50, 3714–3732 (1994).
[CrossRef]

Bruscaglioni, P.

P. Bruscaglioni, G. Zaccanti, Q. Wei, “Transmission of a pulsed polarized light beam through thick turbid media: numerical results,” Appl. Opt. 32, 6142–6150 (1993).
[CrossRef] [PubMed]

P. Bruscaglioni, P. Donelli, A. Ismaelli, G. Zaccanti, “A numerical procedure for calculating the effect of a turbid medium on the MTF of an optical system,” J. Mod. Opt. 38, 129–142 (1991); P. Donelli, P. Bruscaglioni, A. Ismaelli, G. Zaccanti, “Experimental validation of a Monte Carlo procedure for the evaluation of the effect of a turbid medium on the point spread function of an optical system,” J. Mod. Opt. 38, 2189–2201 (1991).
[CrossRef]

Cariou, J.

Chandrasekhar, S.

S. Chandrasekhar, Radiative Transfer (Dover, New York, 1960).

Chang, P. C. Y.

P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Polarization properties of light multiply scattered by non-spherical Rayleigh particles,” Waves Random Media 9, 415–426 (1999).
[CrossRef]

K. Turpin, J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, B. Ablitt, E. Jakeman, “The influence of particle size in active polarization imaging in scattering media,” Opt. Commun. 168, 325–335 (1999).
[CrossRef]

P. C. Y. Chang, J. G. Walker, K. I. Hopcraft, B. Ablitt, E. Jakeman, “Polarization discrimination for active imaging in scattering media,” Opt. Commun. 159, 1–6 (1999).
[CrossRef]

P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Properties of a polarized light-beam multiply scattered by a Rayleigh medium,” in Light Scattering from Microstructures, F. Moreno, F. Gonzalez, eds. (Springer-Verlag, Berlin, 2000).

Christie, S. M.

Coulson, K. L.

K. L. Coulson, J. V. Dave, Z. Sekera, Tables Related to Radiation Emerging from a Planetary Atmosphere with Rayleigh Scattering (University of California, Berkeley, Berkeley, Calif., 1960).

Curran, T. A.

R. X. Li, H. H. Li, W. H. Zou, R. G. Smith, T. A. Smith, T. A. Curran, “Quantitative photogrammatic analysis of digital underwater video imagery,” IEEE J. Ocean. Eng. 22, 364–375 (1997).
[CrossRef]

Dave, J. V.

K. L. Coulson, J. V. Dave, Z. Sekera, Tables Related to Radiation Emerging from a Planetary Atmosphere with Rayleigh Scattering (University of California, Berkeley, Berkeley, Calif., 1960).

Dilworth, D.

Donelli, P.

P. Bruscaglioni, P. Donelli, A. Ismaelli, G. Zaccanti, “A numerical procedure for calculating the effect of a turbid medium on the MTF of an optical system,” J. Mod. Opt. 38, 129–142 (1991); P. Donelli, P. Bruscaglioni, A. Ismaelli, G. Zaccanti, “Experimental validation of a Monte Carlo procedure for the evaluation of the effect of a turbid medium on the point spread function of an optical system,” J. Mod. Opt. 38, 2189–2201 (1991).
[CrossRef]

Evans, K. F.

K. F. Evans, G. L. Stephens, “A new polarized atmospheric radiative transfer model,” J. Quant. Spectrosc. Radiat. Transfer 46, 413–423 (1991).
[CrossRef]

Fantini, S.

Ferrara, A.

S. Bianchi, A. Ferrara, C. Giovanardi, “Monte Carlo simulations of dusty spiral galaxies: extinction and polarization properties,” Astrophys. J. 465, 127–144 (1996).
[CrossRef]

Fischer, O.

O. Fischer, Th. Henning, H. W. Yorke, “Simulation of polarization maps. I. Protostellar envelopes,” Astron. Astrophys. 284, 187–209 (1994).

Forand, J. L.

G. R. Fournier, D. Bonnier, J. L. Forand, P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
[CrossRef]

Fournier, G. R.

G. R. Fournier, D. Bonnier, J. L. Forand, P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
[CrossRef]

Franceschini, M. A.

Gandjbakhche, A. H.

Gilbert, G. D.

Giovanardi, C.

S. Bianchi, A. Ferrara, C. Giovanardi, “Monte Carlo simulations of dusty spiral galaxies: extinction and polarization properties,” Astrophys. J. 465, 127–144 (1996).
[CrossRef]

Gonzalez, R. C.

R. C. Gonzalez, R. E. Woods, Digital Image Processing, 3rd ed. (Addison-Wesley, New York, 1992).

Gouesbet, G.

Guern, Y.

Hansen, J. E.

J. E. Hansen, L. D. Travis, “Light scattering in planetary atmospheres,” Space Sci. Rev. 16, 527–610 (1974).
[CrossRef]

He, J. L.

X. M. Lui, J. L. He, X. H. Sun, M. D. Zhang, “Instrument for collimating and expanding Gaussian beams for underwater laser imaging systems,” Opt. Eng. 37, 2467–2471 (1998).
[CrossRef]

Hebden, J. C.

S. R. Arridge, J. C. Hebden, “Optical imaging in medicine II: modelling and reconstruction techniques,” Phys. Med. Biol. 42, 841–853 (1997).
[CrossRef] [PubMed]

Henney, W. J.

W. J. Henney, D. J. Axon, “Polarization profiles of scattered emission lines. III. Effects of multiple scattering and non-Rayleigh phase functions,” Astrophys. J. 454, 233–253 (1995).
[CrossRef]

Henning, Th.

O. Fischer, Th. Henning, H. W. Yorke, “Simulation of polarization maps. I. Protostellar envelopes,” Astron. Astrophys. 284, 187–209 (1994).

Hopcraft, K. I.

P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Polarization properties of light multiply scattered by non-spherical Rayleigh particles,” Waves Random Media 9, 415–426 (1999).
[CrossRef]

P. C. Y. Chang, J. G. Walker, K. I. Hopcraft, B. Ablitt, E. Jakeman, “Polarization discrimination for active imaging in scattering media,” Opt. Commun. 159, 1–6 (1999).
[CrossRef]

K. Turpin, J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, B. Ablitt, E. Jakeman, “The influence of particle size in active polarization imaging in scattering media,” Opt. Commun. 168, 325–335 (1999).
[CrossRef]

P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Properties of a polarized light-beam multiply scattered by a Rayleigh medium,” in Light Scattering from Microstructures, F. Moreno, F. Gonzalez, eds. (Springer-Verlag, Berlin, 2000).

Igarashi, T.

Ismaelli, A.

P. Bruscaglioni, P. Donelli, A. Ismaelli, G. Zaccanti, “A numerical procedure for calculating the effect of a turbid medium on the MTF of an optical system,” J. Mod. Opt. 38, 129–142 (1991); P. Donelli, P. Bruscaglioni, A. Ismaelli, G. Zaccanti, “Experimental validation of a Monte Carlo procedure for the evaluation of the effect of a turbid medium on the point spread function of an optical system,” J. Mod. Opt. 38, 2189–2201 (1991).
[CrossRef]

Ivanov, A. P.

E. P. Zege, A. P. Ivanov, I. L. Katsev, Image Transfer through a Scattering Medium (Springer-Verlag, Berlin, 1991).
[CrossRef]

Jacques, S. L.

S. L. Jacques, K. Lee, “Imaging tissues with a polarized light video camera,” in 1999 International Conference on Biomedical Optics, Q. Luo, B. Chance, L. V. Wang, S. L. Jacques, eds., Proc. SPIE3863, 68–74 (1999); S. L. Jacques, J. R. Roman, K. Lee, “Imaging superficial tissues with polarized light,” Lasers Surg. Med. 26, 119–129 (2000).
[CrossRef] [PubMed]

Jaffe, J. S.

J. S. Jaffe, K. D. Moore, D. Zawada, B. L. Ochoa, E. Zege, “Underwater optical imaging: new hardware and software,” Sea Technol. 39, 70–74 (1998).

Jakeman, E.

K. Turpin, J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, B. Ablitt, E. Jakeman, “The influence of particle size in active polarization imaging in scattering media,” Opt. Commun. 168, 325–335 (1999).
[CrossRef]

P. C. Y. Chang, J. G. Walker, K. I. Hopcraft, B. Ablitt, E. Jakeman, “Polarization discrimination for active imaging in scattering media,” Opt. Commun. 159, 1–6 (1999).
[CrossRef]

P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Polarization properties of light multiply scattered by non-spherical Rayleigh particles,” Waves Random Media 9, 415–426 (1999).
[CrossRef]

P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Properties of a polarized light-beam multiply scattered by a Rayleigh medium,” in Light Scattering from Microstructures, F. Moreno, F. Gonzalez, eds. (Springer-Verlag, Berlin, 2000).

Jordan, D. L.

Kaschke, M.

Katsev, I. L.

E. P. Zege, A. P. Ivanov, I. L. Katsev, Image Transfer through a Scattering Medium (Springer-Verlag, Berlin, 1991).
[CrossRef]

Kattawar, G. W.

Kvasnik, F.

Le Jeune, B.

Lee, K.

S. L. Jacques, K. Lee, “Imaging tissues with a polarized light video camera,” in 1999 International Conference on Biomedical Optics, Q. Luo, B. Chance, L. V. Wang, S. L. Jacques, eds., Proc. SPIE3863, 68–74 (1999); S. L. Jacques, J. R. Roman, K. Lee, “Imaging superficial tissues with polarized light,” Lasers Surg. Med. 26, 119–129 (2000).
[CrossRef] [PubMed]

Lewis, G. D.

Li, H. H.

R. X. Li, H. H. Li, W. H. Zou, R. G. Smith, T. A. Smith, T. A. Curran, “Quantitative photogrammatic analysis of digital underwater video imagery,” IEEE J. Ocean. Eng. 22, 364–375 (1997).
[CrossRef]

Li, R. X.

R. X. Li, H. H. Li, W. H. Zou, R. G. Smith, T. A. Smith, T. A. Curran, “Quantitative photogrammatic analysis of digital underwater video imagery,” IEEE J. Ocean. Eng. 22, 364–375 (1997).
[CrossRef]

Liu, F.

Lotrian, J.

Lui, X. M.

X. M. Lui, J. L. He, X. H. Sun, M. D. Zhang, “Instrument for collimating and expanding Gaussian beams for underwater laser imaging systems,” Opt. Eng. 37, 2467–2471 (1998).
[CrossRef]

Maheu, B.

Martinez, A. S.

D. Bicout, C. Brosseau, A. S. Martinez, J. M. Schmitt, “Depolarization of multiply scattered waves by spherical diffusers: influence of the size parameter,” Phys. Rev. E 49, 1767–1770 (1994); A. S. Martinez, R. Maynard, “Faraday effect and multiple scattering of light,” Phys. Rev. B 50, 3714–3732 (1994).
[CrossRef]

Mishchenko, M. I.

M. I. Mishchenko, “The fast invariant imbedding method for polarized light: computational aspects and numerical results for Rayleigh scattering,” J. Quant. Spectrosc. Radiat. Transfer 43, 163–171 (1990).
[CrossRef]

Moesta, K. T.

Moore, K. D.

J. S. Jaffe, K. D. Moore, D. Zawada, B. L. Ochoa, E. Zege, “Underwater optical imaging: new hardware and software,” Sea Technol. 39, 70–74 (1998).

Naulleau, P.

Ochoa, B. L.

J. S. Jaffe, K. D. Moore, D. Zawada, B. L. Ochoa, E. Zege, “Underwater optical imaging: new hardware and software,” Sea Technol. 39, 70–74 (1998).

Pace, P. W.

G. R. Fournier, D. Bonnier, J. L. Forand, P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
[CrossRef]

Pernicka, J. C.

Plass, G. N.

Roberts, P. J.

Schlag, P. M.

Schmitt, J. M.

D. Bicout, C. Brosseau, A. S. Martinez, J. M. Schmitt, “Depolarization of multiply scattered waves by spherical diffusers: influence of the size parameter,” Phys. Rev. E 49, 1767–1770 (1994); A. S. Martinez, R. Maynard, “Faraday effect and multiple scattering of light,” Phys. Rev. B 50, 3714–3732 (1994).
[CrossRef]

J. M. Schmitt, A. H. Gandjbakhche, R. F. Bonner, “Use of polarized light to discriminate short-path photons in a multiply scattering medium,” Appl. Opt. 31, 6535–6546 (1992).
[CrossRef] [PubMed]

Sekera, Z.

K. L. Coulson, J. V. Dave, Z. Sekera, Tables Related to Radiation Emerging from a Planetary Atmosphere with Rayleigh Scattering (University of California, Berkeley, Berkeley, Calif., 1960).

Smith, R. G.

R. X. Li, H. H. Li, W. H. Zou, R. G. Smith, T. A. Smith, T. A. Curran, “Quantitative photogrammatic analysis of digital underwater video imagery,” IEEE J. Ocean. Eng. 22, 364–375 (1997).
[CrossRef]

Smith, T. A.

R. X. Li, H. H. Li, W. H. Zou, R. G. Smith, T. A. Smith, T. A. Curran, “Quantitative photogrammatic analysis of digital underwater video imagery,” IEEE J. Ocean. Eng. 22, 364–375 (1997).
[CrossRef]

Stephens, G. L.

K. F. Evans, G. L. Stephens, “A new polarized atmospheric radiative transfer model,” J. Quant. Spectrosc. Radiat. Transfer 46, 413–423 (1991).
[CrossRef]

Sun, X. H.

X. M. Lui, J. L. He, X. H. Sun, M. D. Zhang, “Instrument for collimating and expanding Gaussian beams for underwater laser imaging systems,” Opt. Eng. 37, 2467–2471 (1998).
[CrossRef]

Travis, L. D.

J. E. Hansen, L. D. Travis, “Light scattering in planetary atmospheres,” Space Sci. Rev. 16, 527–610 (1974).
[CrossRef]

Turpin, K.

K. Turpin, J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, B. Ablitt, E. Jakeman, “The influence of particle size in active polarization imaging in scattering media,” Opt. Commun. 168, 325–335 (1999).
[CrossRef]

van de Hulst, H. C.

H. C. van de Hulst, Multiple Light Scattering (Academic, San Diego, Calif.,1980), Vol. 1.

H. C. van de Hulst, Light Scattering by Small Particles (Dover, New York, 1981).

van der Mee, C. V. M.

C. V. M. van der Mee, “Eigenvalue criterion for polarization matrices,” J. Math. Phys. 34, 5072–5088 (1993).
[CrossRef]

Walker, J. G.

P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Polarization properties of light multiply scattered by non-spherical Rayleigh particles,” Waves Random Media 9, 415–426 (1999).
[CrossRef]

K. Turpin, J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, B. Ablitt, E. Jakeman, “The influence of particle size in active polarization imaging in scattering media,” Opt. Commun. 168, 325–335 (1999).
[CrossRef]

P. C. Y. Chang, J. G. Walker, K. I. Hopcraft, B. Ablitt, E. Jakeman, “Polarization discrimination for active imaging in scattering media,” Opt. Commun. 159, 1–6 (1999).
[CrossRef]

P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Properties of a polarized light-beam multiply scattered by a Rayleigh medium,” in Light Scattering from Microstructures, F. Moreno, F. Gonzalez, eds. (Springer-Verlag, Berlin, 2000).

Walker, S. A.

Wei, Q.

Woods, R. E.

R. C. Gonzalez, R. E. Woods, Digital Image Processing, 3rd ed. (Addison-Wesley, New York, 1992).

Yorke, H. W.

O. Fischer, Th. Henning, H. W. Yorke, “Simulation of polarization maps. I. Protostellar envelopes,” Astron. Astrophys. 284, 187–209 (1994).

Zaccanti, G.

P. Bruscaglioni, G. Zaccanti, Q. Wei, “Transmission of a pulsed polarized light beam through thick turbid media: numerical results,” Appl. Opt. 32, 6142–6150 (1993).
[CrossRef] [PubMed]

P. Bruscaglioni, P. Donelli, A. Ismaelli, G. Zaccanti, “A numerical procedure for calculating the effect of a turbid medium on the MTF of an optical system,” J. Mod. Opt. 38, 129–142 (1991); P. Donelli, P. Bruscaglioni, A. Ismaelli, G. Zaccanti, “Experimental validation of a Monte Carlo procedure for the evaluation of the effect of a turbid medium on the point spread function of an optical system,” J. Mod. Opt. 38, 2189–2201 (1991).
[CrossRef]

Zawada, D.

J. S. Jaffe, K. D. Moore, D. Zawada, B. L. Ochoa, E. Zege, “Underwater optical imaging: new hardware and software,” Sea Technol. 39, 70–74 (1998).

Zege, E.

J. S. Jaffe, K. D. Moore, D. Zawada, B. L. Ochoa, E. Zege, “Underwater optical imaging: new hardware and software,” Sea Technol. 39, 70–74 (1998).

Zege, E. P.

E. P. Zege, A. P. Ivanov, I. L. Katsev, Image Transfer through a Scattering Medium (Springer-Verlag, Berlin, 1991).
[CrossRef]

Zhang, M. D.

X. M. Lui, J. L. He, X. H. Sun, M. D. Zhang, “Instrument for collimating and expanding Gaussian beams for underwater laser imaging systems,” Opt. Eng. 37, 2467–2471 (1998).
[CrossRef]

Zou, W. H.

R. X. Li, H. H. Li, W. H. Zou, R. G. Smith, T. A. Smith, T. A. Curran, “Quantitative photogrammatic analysis of digital underwater video imagery,” IEEE J. Ocean. Eng. 22, 364–375 (1997).
[CrossRef]

Appl. Opt. (13)

P. Naulleau, D. Dilworth, “Motion-resolved imaging of moving objects embedded within scattering media by the use of time-gated speckle analysis,” Appl. Opt. 35, 5251–5257 (1996).
[CrossRef] [PubMed]

S. Fantini, S. A. Walker, M. A. Franceschini, M. Kaschke, P. M. Schlag, K. T. Moesta, “Assessment of the size, position, and optical properties of breast tumors in vivo by noninvasive optical methods,“ Appl. Opt. 37, 1982–1989 (1998).

S. M. Christie, F. Kvasnik, “Contrast enhancement of underwater images with coherent optical image processors,” Appl. Opt. 35, 817–825 (1996).
[CrossRef] [PubMed]

G. D. Gilbert, J. C. Pernicka, “Improvement of underwater visibility by reduction of backscatter with a circular polarization technique,” Appl. Opt. 6, 741–746 (1967).
[CrossRef] [PubMed]

J. Cariou, B. Le Jeune, J. Lotrian, Y. Guern, “Polarization effects of seawater and underwater targets,” Appl. Opt. 29, 1689–1695 (1990).
[CrossRef] [PubMed]

G. N. Plass, G. W. Kattawar, “Monte Carlo calculations of light scattering from clouds,” Appl. Opt. 7, 415–419 (1968).
[CrossRef] [PubMed]

G. N. Plass, G. W. Kattawar, “Reflection of light pulses from clouds,” Appl. Opt. 10, 2304–2310 (1971); E. A. Bucher, “Computer simulation of light pulse propagation for communication through thick clouds,” Appl. Opt. 12, 2391–2400 (1973).
[CrossRef] [PubMed]

B. Maheu, J.-P. Briton, G. Gouesbet, “Four-flux model and a Monte Carlo code: comparisons between two simple, complementary tools for multiple scattering calculations,” Appl. Opt. 28, 22–24 (1989); J.-P. Briton, B. Maheu, G. Gréhan, G. Gouesbet, “Monte Carlo simulation of multiple scattering in arbitrary 3-D geometry,” Part. Part. Syst. Charact. 9, 52–58 (1992).
[CrossRef] [PubMed]

G. W. Kattawar, G. N. Plass, “Radiance and polarization of multiple scattered light from haze and clouds,” Appl. Opt. 7, 1519–1527 (1968); G. W. Kattawar, G. N. Plass, “Degree and direction of polarization of multiple scattered light. 1. Homogeneous cloud layers,” Appl. Opt. 11, 2851–2865 (1972).
[CrossRef] [PubMed]

T. Aruga, T. Igarashi, “Narrow beam light transfer in small particles: image blurring and depolarization,” Appl. Opt. 20, 2698–2705 (1981); erratum, 20, 3831 (1981).

J. M. Schmitt, A. H. Gandjbakhche, R. F. Bonner, “Use of polarized light to discriminate short-path photons in a multiply scattering medium,” Appl. Opt. 31, 6535–6546 (1992).
[CrossRef] [PubMed]

P. Bruscaglioni, G. Zaccanti, Q. Wei, “Transmission of a pulsed polarized light beam through thick turbid media: numerical results,” Appl. Opt. 32, 6142–6150 (1993).
[CrossRef] [PubMed]

G. D. Lewis, D. L. Jordan, P. J. Roberts, “Backscattering target detection in a turbid medium using polarization discrimination,” Appl. Opt. 38, 3937–3944 (1999).
[CrossRef]

Astron. Astrophys. (1)

O. Fischer, Th. Henning, H. W. Yorke, “Simulation of polarization maps. I. Protostellar envelopes,” Astron. Astrophys. 284, 187–209 (1994).

Astrophys. J. (2)

W. J. Henney, D. J. Axon, “Polarization profiles of scattered emission lines. III. Effects of multiple scattering and non-Rayleigh phase functions,” Astrophys. J. 454, 233–253 (1995).
[CrossRef]

S. Bianchi, A. Ferrara, C. Giovanardi, “Monte Carlo simulations of dusty spiral galaxies: extinction and polarization properties,” Astrophys. J. 465, 127–144 (1996).
[CrossRef]

IEEE J. Ocean. Eng. (1)

R. X. Li, H. H. Li, W. H. Zou, R. G. Smith, T. A. Smith, T. A. Curran, “Quantitative photogrammatic analysis of digital underwater video imagery,” IEEE J. Ocean. Eng. 22, 364–375 (1997).
[CrossRef]

J. Math. Phys. (1)

C. V. M. van der Mee, “Eigenvalue criterion for polarization matrices,” J. Math. Phys. 34, 5072–5088 (1993).
[CrossRef]

J. Mod. Opt. (1)

P. Bruscaglioni, P. Donelli, A. Ismaelli, G. Zaccanti, “A numerical procedure for calculating the effect of a turbid medium on the MTF of an optical system,” J. Mod. Opt. 38, 129–142 (1991); P. Donelli, P. Bruscaglioni, A. Ismaelli, G. Zaccanti, “Experimental validation of a Monte Carlo procedure for the evaluation of the effect of a turbid medium on the point spread function of an optical system,” J. Mod. Opt. 38, 2189–2201 (1991).
[CrossRef]

J. Quant. Spectrosc. Radiat. Transfer (2)

K. F. Evans, G. L. Stephens, “A new polarized atmospheric radiative transfer model,” J. Quant. Spectrosc. Radiat. Transfer 46, 413–423 (1991).
[CrossRef]

M. I. Mishchenko, “The fast invariant imbedding method for polarized light: computational aspects and numerical results for Rayleigh scattering,” J. Quant. Spectrosc. Radiat. Transfer 43, 163–171 (1990).
[CrossRef]

Opt. Commun. (2)

P. C. Y. Chang, J. G. Walker, K. I. Hopcraft, B. Ablitt, E. Jakeman, “Polarization discrimination for active imaging in scattering media,” Opt. Commun. 159, 1–6 (1999).
[CrossRef]

K. Turpin, J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, B. Ablitt, E. Jakeman, “The influence of particle size in active polarization imaging in scattering media,” Opt. Commun. 168, 325–335 (1999).
[CrossRef]

Opt. Eng. (2)

G. R. Fournier, D. Bonnier, J. L. Forand, P. W. Pace, “Range-gated underwater laser imaging system,” Opt. Eng. 32, 2185–2190 (1993).
[CrossRef]

X. M. Lui, J. L. He, X. H. Sun, M. D. Zhang, “Instrument for collimating and expanding Gaussian beams for underwater laser imaging systems,” Opt. Eng. 37, 2467–2471 (1998).
[CrossRef]

Opt. Lett. (1)

Phys. Med. Biol. (1)

S. R. Arridge, J. C. Hebden, “Optical imaging in medicine II: modelling and reconstruction techniques,” Phys. Med. Biol. 42, 841–853 (1997).
[CrossRef] [PubMed]

Phys. Rev. E (1)

D. Bicout, C. Brosseau, A. S. Martinez, J. M. Schmitt, “Depolarization of multiply scattered waves by spherical diffusers: influence of the size parameter,” Phys. Rev. E 49, 1767–1770 (1994); A. S. Martinez, R. Maynard, “Faraday effect and multiple scattering of light,” Phys. Rev. B 50, 3714–3732 (1994).
[CrossRef]

Sea Technol. (1)

J. S. Jaffe, K. D. Moore, D. Zawada, B. L. Ochoa, E. Zege, “Underwater optical imaging: new hardware and software,” Sea Technol. 39, 70–74 (1998).

Space Sci. Rev. (1)

J. E. Hansen, L. D. Travis, “Light scattering in planetary atmospheres,” Space Sci. Rev. 16, 527–610 (1974).
[CrossRef]

Waves Random Media (1)

P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Polarization properties of light multiply scattered by non-spherical Rayleigh particles,” Waves Random Media 9, 415–426 (1999).
[CrossRef]

Other (11)

K. L. Coulson, J. V. Dave, Z. Sekera, Tables Related to Radiation Emerging from a Planetary Atmosphere with Rayleigh Scattering (University of California, Berkeley, Berkeley, Calif., 1960).

H. C. van de Hulst, Multiple Light Scattering (Academic, San Diego, Calif.,1980), Vol. 1.

H. C. van de Hulst, Light Scattering by Small Particles (Dover, New York, 1981).

M. I. Mishchenko, J. W. Hovenier, L. D. Travis, eds., Light Scattering by Nonspherical Particles (Academic, San Diego, Calif., 2000).

S. Chandrasekhar, Radiative Transfer (Dover, New York, 1960).

P. C. Y. Chang, J. G. Walker, E. Jakeman, K. I. Hopcraft, “Properties of a polarized light-beam multiply scattered by a Rayleigh medium,” in Light Scattering from Microstructures, F. Moreno, F. Gonzalez, eds. (Springer-Verlag, Berlin, 2000).

E. P. Zege, A. P. Ivanov, I. L. Katsev, Image Transfer through a Scattering Medium (Springer-Verlag, Berlin, 1991).
[CrossRef]

S. L. Jacques, K. Lee, “Imaging tissues with a polarized light video camera,” in 1999 International Conference on Biomedical Optics, Q. Luo, B. Chance, L. V. Wang, S. L. Jacques, eds., Proc. SPIE3863, 68–74 (1999); S. L. Jacques, J. R. Roman, K. Lee, “Imaging superficial tissues with polarized light,” Lasers Surg. Med. 26, 119–129 (2000).
[CrossRef] [PubMed]

B. Chance, R. R. Alfano, eds., Optical Tomography, Photon Migration, and Spectroscopy of Tissue And Model Media: Theory, Human Studies, and Instrumentation, Proc. SPIE2389 (1995).

M. Barrow, “Imaging through obscurants,” Ph.D. dissertation (University of London, London, 1996).

R. C. Gonzalez, R. E. Woods, Digital Image Processing, 3rd ed. (Addison-Wesley, New York, 1992).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (11)

Fig. 1
Fig. 1

Plots of the first two Stokes parameters against the cosine of the zenith angle from published data (labeled Coulson), AD code, and the simulation (MC). The upper graph represents I, the lower, Q, for a plane-parallel slab of thickness 1 mfp with Rayleigh scatterers.

Fig. 2
Fig. 2

Plots of the first three Stokes parameters against the cosine of the zenith angle from published data (labeled Mish), AD code, and the simulation (MC). The upper graphs represents I; the middle graphs, Q; and the lower graph, U. The columns, from left to right, show the results at azimuthal angles of 0°, 90°, and 180°.

Fig. 3
Fig. 3

Surface plots of the first two columns of the Mueller matrix. The set of plots in the two leftmost columns represents results from the AD code, and simulated data are shown in the two rightmost columns. The axis that runs from 0° to 90° is the zenith angle θ, and the axis that ranges from 0° to 180° is the azimuthal angle ϕ.

Fig. 4
Fig. 4

Simulation geometry with an f/1 focusing arrangement.

Fig. 5
Fig. 5

Summary of the images from an object behind a medium of Mie scatterers (ka = 0.01) illuminated with a collimated source and imaged with a simulated f/1 optical system. Each column represents a different imaging technique: The first is the unfiltered intensity, the second is the copolarized output, the third is the opposite-polarized output, the fourth is the optimal linear combination of the opposite-polarized image and the copolarized image, the fifth is the optimal combination of the unfiltered and defocused images, and the final column is the optimal unsharp masked image. The rows, from top to bottom, represent different object depths z = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 mfp.

Fig. 6
Fig. 6

Results of applying polarization enhancement, at a target depth of z = 1.5 mfp. Each image represents a linear combination of the opposite-polarized image and the copolarized image—the combinations are fractions, ranging from 0% to 20% in intervals of 2%, of the copolarized image subtracted from the opposite-polarized one.

Fig. 7
Fig. 7

Image contrast as a function of the fraction of the copolarized image subtracted from the opposite-polarized image. The curve corresponds to the polarization-enhanced images for a target depth of z = 1.5 mfp shown in Fig. 6.

Fig. 8
Fig. 8

Results of applying defocusing enhancement, at a target depth of z = 1.5 mfp. Each image represents a linear combination of the focused and the defocused images—the combinations are fractions, ranging from 0% to 50% in intervals of 5%, of the defocused images subtracted from the focused one. The defocused image is formed closer to the lens than the focused image (at v - δf, where v is the distance of lens to focused image, f is the focal length, and δ = 0.50).

Fig. 9
Fig. 9

Image contrast as a function of the fraction of defocused image subtracted from the focused image. The different curves correspond to different defocus distances. The curve for δ = 0.5 corresponds to that used in Fig. 8.

Fig. 10
Fig. 10

Results of applying unsharp masking enhancement, at a target depth of z = 1.5 mfp. Each image is a linear combination of the original image and a Gaussian-filtered image. The filter width is w = 0.032 pixel-1. From left to right the fraction of the filtered image subtracted from the original image varies from 94% to 130% in steps of 4%.

Fig. 11
Fig. 11

Image contrast as a function of the fraction of filtered image subtracted from the original image. The different curves correspond to different Gaussian-filter widths. The curve for w = 0.032 pixel-1 corresponds to that used in Fig. 10.

Equations (2)

Equations on this page are rendered with MathJax. Learn more.

M(α, β, γ)=103T03R(α, β, γ),
M=1000000000000000,

Metrics