Abstract

Results are presented that demonstrate the effectiveness of using polarization discrimination to improve visibility when imaging in a scattering medium. The study is motivated by the desire to improve visibility depth in turbid environments, such as the sea. Most previous research in this area has concentrated on the active illumination of objects with polarized light. We consider passive or ambient illumination, such as that deriving from sunlight or a cloudy sky. The basis for the improvements in visibility observed is that single scattering by small particles introduces a significant amount of polarization into light at scattering angles near 90°: This light can then be distinguished from light scattered by an object that remains almost completely unpolarized. Results were obtained from a Monte Carlo simulation and from a small-scale experiment in which an object was immersed in a cell filled with polystyrene latex spheres suspended in water. In both cases, the results showed an improvement in contrast and visibility depth for obscuration that was due to Rayleigh particles, but less improvement was obtained for larger scatterers.

© 2003 Optical Society of America

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References

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  1. J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, “Visibility depth improvement in active polarization imaging in scattering media,” Appl. Opt. 39, 4933–4941 (2000).
    [CrossRef]
  2. 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]
  3. 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]
  4. 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).
  5. 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]
  6. S. M. Christie, F. Kvasnik, “Contrast enhancement of underwater images with coherent optical image processors,” Appl. Opt. 35, 817–825 (1996).
    [CrossRef] [PubMed]
  7. 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]
  8. 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]
  9. J. Cariou, B. Le Jeune, J. Lotrian, Y. Guern, “Polarization effects of seawater and underwater targets,” Appl. Opt. 29, 1689–1695 (1990).
    [CrossRef] [PubMed]
  10. J. S. Tyo, M. P. Rowe, E. N. Pugh, N. Engheta, “Target detection in optically scattering media by polarization-difference imaging,” Appl. Opt. 35, 1855–1870 (1996).
    [CrossRef] [PubMed]
  11. N. G. Jerlov, “Optical Oceanography,” in The Encyclopedia of Oceanography, R. W. Fairbridge, ed. (Reinhold, New York, 1966), pp. 619–632.
  12. S. Q. Duntley, “Underwater visibility and photography,” in Optical Aspects of Oceanography, N. G. Jerlov, ed. (Academic, London, 1974), pp. 138–149.
  13. M. G. J. Minnaert, Light and Color in the Outdoors (Springer Verlag, New York, 1993), plate 33.
    [CrossRef]
  14. N. Shashar, R. T. Hanlon, A. deM. Petz, “Polarization vision helps detect transparent prey,” Nature 393, 222–223 (1998).
    [CrossRef]
  15. K. L. Coulson, Solar and Terrestrial Radiation (Academic, New York, 1975).
  16. 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]
  17. C. F. Bohren, D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley, New York, 1983).

2000

1999

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]

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]

N. Shashar, R. T. Hanlon, A. deM. Petz, “Polarization vision helps detect transparent prey,” Nature 393, 222–223 (1998).
[CrossRef]

1997

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]

1996

1993

1990

1967

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]

Bohren, C. F.

C. F. Bohren, D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley, New York, 1983).

Bruscaglioni, P.

Cariou, J.

Chang, P. C. Y.

J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, “Visibility depth improvement in active polarization imaging in scattering media,” Appl. Opt. 39, 4933–4941 (2000).
[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]

Christie, S. M.

Coulson, K. L.

K. L. Coulson, Solar and Terrestrial Radiation (Academic, New York, 1975).

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]

deM. Petz, A.

N. Shashar, R. T. Hanlon, A. deM. Petz, “Polarization vision helps detect transparent prey,” Nature 393, 222–223 (1998).
[CrossRef]

Duntley, S. Q.

S. Q. Duntley, “Underwater visibility and photography,” in Optical Aspects of Oceanography, N. G. Jerlov, ed. (Academic, London, 1974), pp. 138–149.

Engheta, N.

Gilbert, G. D.

Guern, Y.

Hanlon, R. T.

N. Shashar, R. T. Hanlon, A. deM. Petz, “Polarization vision helps detect transparent prey,” Nature 393, 222–223 (1998).
[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]

Hopcraft, K. I.

J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, “Visibility depth improvement in active polarization imaging in scattering media,” Appl. Opt. 39, 4933–4941 (2000).
[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]

Huffman, D. R.

C. F. Bohren, D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley, New York, 1983).

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.

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]

Jerlov, N. G.

N. G. Jerlov, “Optical Oceanography,” in The Encyclopedia of Oceanography, R. W. Fairbridge, ed. (Reinhold, New York, 1966), pp. 619–632.

Kvasnik, F.

Le Jeune, B.

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]

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]

Minnaert, M. G. J.

M. G. J. Minnaert, Light and Color in the Outdoors (Springer Verlag, New York, 1993), plate 33.
[CrossRef]

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).

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).

Pernicka, J. C.

Pugh, E. N.

Rowe, M. P.

Shashar, N.

N. Shashar, R. T. Hanlon, A. deM. Petz, “Polarization vision helps detect transparent prey,” Nature 393, 222–223 (1998).
[CrossRef]

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]

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]

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]

Tyo, J. S.

Walker, J. G.

J. G. Walker, P. C. Y. Chang, K. I. Hopcraft, “Visibility depth improvement in active polarization imaging in scattering media,” Appl. Opt. 39, 4933–4941 (2000).
[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]

Wei, Q.

Zaccanti, G.

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).

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.

IEEE J. Ocean. Eng.

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]

Nature

N. Shashar, R. T. Hanlon, A. deM. Petz, “Polarization vision helps detect transparent prey,” Nature 393, 222–223 (1998).
[CrossRef]

Opt. Commun.

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]

Opt. Eng.

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]

Sea Technol.

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).

Other

K. L. Coulson, Solar and Terrestrial Radiation (Academic, New York, 1975).

C. F. Bohren, D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley, New York, 1983).

N. G. Jerlov, “Optical Oceanography,” in The Encyclopedia of Oceanography, R. W. Fairbridge, ed. (Reinhold, New York, 1966), pp. 619–632.

S. Q. Duntley, “Underwater visibility and photography,” in Optical Aspects of Oceanography, N. G. Jerlov, ed. (Academic, London, 1974), pp. 138–149.

M. G. J. Minnaert, Light and Color in the Outdoors (Springer Verlag, New York, 1993), plate 33.
[CrossRef]

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Figures (12)

Fig. 1
Fig. 1

Geometry of the air–liquid system. A spherical object is submerged in a scattering medium comprising much smaller spherical particles. A camera, of length 0.4 and radius 0.01, is placed on the same horizontal plane as the object and its distance to the object Δ can be varied. Illumination is from above and from models given by idealized sky models. All dimensions are given in terms of the effective mean free path, which is set to 1 unit.

Fig. 2
Fig. 2

Coordinate system for scattering from a single Rayleigh particle at the origin. The angle that the incident ray (parallel to the YZ plane) makes with the vertical is θ i , the ray is scattered such that its new direction has an angle θ s to the vertical, and ϕ is the angle between the incident plane and the plane containing the scattered ray and the vertical axis.

Fig. 3
Fig. 3

Effect of a surface interface on the degree of polarization of scattered light from a Rayleigh particle. The degree of polarization for light scattered into the horizontal plane is plotted as a function of illumination angle θ a . Note that when there is no interface θ a = θ i . The solid curve, the degree of polarization without refraction through a surface; the dashed curve, the degree of polarization with refraction through a surface.

Fig. 4
Fig. 4

Simulated images for a turbid medium containing Rayleigh particles with illumination from zenith onto an object of size 0.2 units and an albedo of unity. The images shown are total intensity, I; TDOP; and the enhancement, E, produced by Eq. (10). The camera to object distance, Δ, in the top row is set to 1, and each subsequent row represent increments of 0.5 to a final Δ = 2.5.

Fig. 5
Fig. 5

Simulated images for a turbid medium containing Rayleigh particles with illumination from zenith and an object of size 0.2 units and an albedo of 0.5. The images shown are total intensity, I; TDOP; and the enhancement, E, produced by Eq. (10). The camera to object distance, Δ, in the top row is set to 1, and each subsequent row represent increments of 0.5 to a final Δ = 2.5.

Fig. 6
Fig. 6

Apparent contrast between the object and the surrounding area. (a) and (b) Variation of contrast with camera-to-object distance for the situation simulated in Fig. 4. Asterisks, the contrast in the intensity for the lower half of the object. Crosses, the contrast in the intensity for the upper half of the object. Solid and open squares, the contrast in the S image, for the lower and upper halves of the object, respectively. Solid and open circles, the contrast in U, for the lower and upper halves of the object, respectively. Solid and open triangles, the contrast in the enhanced image E, Eq. (10), for the lower and upper halves of the object, respectively. (c) The corresponding contrast variations for the situation simulated in Fig. 5. (d) The contrast variation with the object albedo for a camera-to-object distance of 1 unit.

Fig. 7
Fig. 7

Apparent contrast between the object and the surrounding area. (a) Variation of the contrast with camera-to-object distance for a situation similar to that of Fig. 4 but in which the illumination is from an overcast sky model rather than a source at zenith. (b) Variation of the contrast with camera-to-object distance for a situation similar to that of Fig. 4 but in which the object is modeled as having a scattering surface that preserves the incident polarization state. Symbols used have the same meaning as in Fig. 6.

Fig. 8
Fig. 8

Simulated images for a medium populated with Mie scatterers with ka = 1 and n rel = 1.2. Illumination is from the zenith. The layout is the same as the images of Figs. 4 and 5. The effective mean free path is set to 1 to allow comparison with the Rayleigh simulations and corresponds to a mean free path of approximately 0.824.

Fig. 9
Fig. 9

Apparent contrast between the object and the surrounding area. (a) Variation of the contrast with camera-to-object distance for the situation of Fig. 8. (b) Variation of the contrast with the value of ka. Symbols used have the same meaning as in Fig. 6.

Fig. 10
Fig. 10

Images from the experiment performed with Rayleigh scatterers with Δ = 10 mm.

Fig. 11
Fig. 11

Images from the experiment performed with Mie scatterers with Δ = 10 mm.

Fig. 12
Fig. 12

Apparent contrast for the experimental images between the object and the surrounding area. (a) Variation of the contrast with camera-to-object distance for the situation of Fig. 10. (b) Variation of the contrast with camera-to-object distance for the situation of Fig. 11. Symbols used have the same meaning as in Fig. 6.

Equations (14)

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

Iθi, ϕi=Iδθl-θiδϕl-ϕi,
Iθi, ϕi=I1+2 cosθi3.
Fv=fh sin ϕ cos θs+fvsin θi sin θs-cos θi cos θs cos ϕ,Fh=fh cos ϕ+fv cos θi sin ϕ,
SsIsQsUsVs=|Fv|2+|Fh|2|Fh|2-|Fv|2FhFv*+FvFh*iFhFv*-FvFh*.
TDOP=Q2+U2+V21/2I,
TDOP=sin2 θs1+cos2 θs,
TDOP=1-2|fhfv|sin θi cos ϕ|fh|2 cos2 ϕ+|fv|2cos2 θi sin2 ϕ+sin2 θi21/2.
sin θi=1nsin θa,
|fh|2=2 cos θacos θa+n2-sin2 θa1/22A,|fv|2=2n cos θan2 cos θa+n2-sin2 θa1/22A,
A=n2-sin2 θa1/2cos θa.
TDOP=1-2B sin θa cos ϕB2 cos2 ϕ+n2 sin2 ϕ+sin2 θa cos2 ϕ21/2,
B=n2 cos θa+n2-sin2 θa1/2cos θa+n2-sin2 θa1/2.
E=TDOPmax-TDOPI-Imin,
Contrast=F-BF+B.

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