Abstract

A partially light-controlled imaging system is proposed as a novel device. It is used to improve the imaging quality at the illumination of 1.979 × 105lx by means of mitigating image contrast. It consists of a High Temperature Poly-Silicon Thin Film Transistor-Liquid Crystal Display (HTPS TFT-LCD), which is set between the lens and CCD and is coupled with CCD by the optical fiber taper. The transmittance of pixelated LCD can be controlled by Field-Programmable Gate Array to realize the partially light-controlled and thus dynamic range of the imaging system can be extended. Samples of indoor objects and outdoor license plate are photographed by the prototype imaging system under strong light. The imaging results of this novel system are satisfactory with better restored details, compared with the photos taken by normal CCD camera (WAT-231S2) which uses aperture and shutter to control the overall light intensity.

© 2010 OSA

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References

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2010 (1)

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

2009 (3)

C. C. Fang, T. D. Cheng, J. T. Yeh, K.-C. Wu, and C. K. Lee, “Continuous numerical aperture properties of a cylindrically polarized light illuminated sub-wavelength annular aperture,” Opt. Express 17(16), 13646–13653 (2009), http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-17-16-13646 .
[PubMed]

R. X. Zhang, Y. H. Tang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Partial gating image intensifier based on liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

X. S. Yang, Y. H. Tang, K. Liu, H. C. Liu, H. Y. Gao, Q. Li, R. X. Zhang, N. Ye, Y. Liang, and G. X. Zhao, “Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

2008 (3)

2003 (2)

2002 (1)

L. X. Jin, Z. M. Lv, and J. W. Xiong, “Automatic light adjusting system of CCD video camera,” Opt. Precis. Eng. 10, 588–591 (2002).

2001 (1)

A. Marquez, C. Lemmi, I. Moreno, J. A. Davis, J. Campos, and M. J. Yzuel, “Quantitative prediction of the modulation behavior of twisted nematic liquid crystal displays based on a simple physical model,” Opt. Eng. 40(11), 2558–2564 (2001).

1997 (1)

1995 (1)

Au, A.

Campos, J.

A. Marquez, C. Lemmi, I. Moreno, J. A. Davis, J. Campos, and M. J. Yzuel, “Quantitative prediction of the modulation behavior of twisted nematic liquid crystal displays based on a simple physical model,” Opt. Eng. 40(11), 2558–2564 (2001).

Cheng, T. D.

Davis, J. A.

A. Marquez, C. Lemmi, I. Moreno, J. A. Davis, J. Campos, and M. J. Yzuel, “Quantitative prediction of the modulation behavior of twisted nematic liquid crystal displays based on a simple physical model,” Opt. Eng. 40(11), 2558–2564 (2001).

Domján, L.

Efron, U.

Estrera, J. P.

J. P. Estrera and M. R. Sakdana, “High-Speed photocathode gating for generation III image intensifier applications,” Proc. SPIE 5079, 212–220 (2003).

Fang, C. C.

Gao, H. Y.

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

X. S. Yang, Y. H. Tang, K. Liu, H. C. Liu, H. Y. Gao, Q. Li, R. X. Zhang, N. Ye, Y. Liang, and G. X. Zhao, “Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

R. X. Zhang, Y. H. Tang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Partial gating image intensifier based on liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

Hernández-Andrés, J.

Jin, L. X.

L. X. Jin, Z. M. Lv, and J. W. Xiong, “Automatic light adjusting system of CCD video camera,” Opt. Precis. Eng. 10, 588–591 (2002).

Koppa, P.

Kupfer, T.

Lee, C. K.

Lemmi, C.

A. Marquez, C. Lemmi, I. Moreno, J. A. Davis, J. Campos, and M. J. Yzuel, “Quantitative prediction of the modulation behavior of twisted nematic liquid crystal displays based on a simple physical model,” Opt. Eng. 40(11), 2558–2564 (2001).

Li, Q.

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

X. S. Yang, Y. H. Tang, K. Liu, H. C. Liu, H. Y. Gao, Q. Li, R. X. Zhang, N. Ye, Y. Liang, and G. X. Zhao, “Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

R. X. Zhang, Y. H. Tang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Partial gating image intensifier based on liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

Liang, Y.

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

X. S. Yang, Y. H. Tang, K. Liu, H. C. Liu, H. Y. Gao, Q. Li, R. X. Zhang, N. Ye, Y. Liang, and G. X. Zhao, “Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

R. X. Zhang, Y. H. Tang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Partial gating image intensifier based on liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

Liu, H. C.

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

X. S. Yang, Y. H. Tang, K. Liu, H. C. Liu, H. Y. Gao, Q. Li, R. X. Zhang, N. Ye, Y. Liang, and G. X. Zhao, “Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

R. X. Zhang, Y. H. Tang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Partial gating image intensifier based on liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

Liu, K.

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

R. X. Zhang, Y. H. Tang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Partial gating image intensifier based on liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

X. S. Yang, Y. H. Tang, K. Liu, H. C. Liu, H. Y. Gao, Q. Li, R. X. Zhang, N. Ye, Y. Liang, and G. X. Zhao, “Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

Liu, S. L.

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

López-Álvarez, M. A.

Lõrincz, E.

Lv, Z. M.

L. X. Jin, Z. M. Lv, and J. W. Xiong, “Automatic light adjusting system of CCD video camera,” Opt. Precis. Eng. 10, 588–591 (2002).

Marquez, A.

A. Marquez, C. Lemmi, I. Moreno, J. A. Davis, J. Campos, and M. J. Yzuel, “Quantitative prediction of the modulation behavior of twisted nematic liquid crystal displays based on a simple physical model,” Opt. Eng. 40(11), 2558–2564 (2001).

Moreno, I.

A. Marquez, C. Lemmi, I. Moreno, J. A. Davis, J. Campos, and M. J. Yzuel, “Quantitative prediction of the modulation behavior of twisted nematic liquid crystal displays based on a simple physical model,” Opt. Eng. 40(11), 2558–2564 (2001).

Mosk, A. P.

Reményi, J.

Romero, J.

Sakdana, M. R.

J. P. Estrera and M. R. Sakdana, “High-Speed photocathode gating for generation III image intensifier applications,” Proc. SPIE 5079, 212–220 (2003).

Stojanovic, N.

Tang, Y. H.

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

X. S. Yang, Y. H. Tang, K. Liu, H. C. Liu, H. Y. Gao, Q. Li, R. X. Zhang, N. Ye, Y. Liang, and G. X. Zhao, “Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

R. X. Zhang, Y. H. Tang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Partial gating image intensifier based on liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

Trigt, C. V.

van Putten, E. G.

Várhegyi, P.

Vellekoop, I. M.

Wu, C.-S.

Wu, K.-C.

Wu, S.-T.

Xiong, J. W.

L. X. Jin, Z. M. Lv, and J. W. Xiong, “Automatic light adjusting system of CCD video camera,” Opt. Precis. Eng. 10, 588–591 (2002).

Yang, X. S.

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

R. X. Zhang, Y. H. Tang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Partial gating image intensifier based on liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

X. S. Yang, Y. H. Tang, K. Liu, H. C. Liu, H. Y. Gao, Q. Li, R. X. Zhang, N. Ye, Y. Liang, and G. X. Zhao, “Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

Ye, N.

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

X. S. Yang, Y. H. Tang, K. Liu, H. C. Liu, H. Y. Gao, Q. Li, R. X. Zhang, N. Ye, Y. Liang, and G. X. Zhao, “Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

R. X. Zhang, Y. H. Tang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Partial gating image intensifier based on liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

Yeh, J. T.

Yzuel, M. J.

A. Marquez, C. Lemmi, I. Moreno, J. A. Davis, J. Campos, and M. J. Yzuel, “Quantitative prediction of the modulation behavior of twisted nematic liquid crystal displays based on a simple physical model,” Opt. Eng. 40(11), 2558–2564 (2001).

Zhang, R. X.

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

X. S. Yang, Y. H. Tang, K. Liu, H. C. Liu, H. Y. Gao, Q. Li, R. X. Zhang, N. Ye, Y. Liang, and G. X. Zhao, “Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

R. X. Zhang, Y. H. Tang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Partial gating image intensifier based on liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

Zhao, G. X.

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

X. S. Yang, Y. H. Tang, K. Liu, H. C. Liu, H. Y. Gao, Q. Li, R. X. Zhang, N. Ye, Y. Liang, and G. X. Zhao, “Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

R. X. Zhang, Y. H. Tang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Partial gating image intensifier based on liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

Appl. Opt. (4)

Chinese J. Liq. Cryst. Displays. (1)

Y. H. Tang, R. X. Zhang, H. C. Liu, S. L. Liu, K. Liu, H. Y. Gao, X. S. Yang, G. X. Zhao, Q. Li, Y. Liang, and N. Ye, “Study of LCD transmission spectrum based on light intensity gated imaging,” Chinese J. Liq. Cryst. Displays. 25, 200–204 (2010).

J. Lightwave Technol. (1)

J. Opt. Soc. Am. A (1)

Opt. Eng. (1)

A. Marquez, C. Lemmi, I. Moreno, J. A. Davis, J. Campos, and M. J. Yzuel, “Quantitative prediction of the modulation behavior of twisted nematic liquid crystal displays based on a simple physical model,” Opt. Eng. 40(11), 2558–2564 (2001).

Opt. Express (1)

Opt. Precis. Eng. (1)

L. X. Jin, Z. M. Lv, and J. W. Xiong, “Automatic light adjusting system of CCD video camera,” Opt. Precis. Eng. 10, 588–591 (2002).

Proc. SPIE (3)

J. P. Estrera and M. R. Sakdana, “High-Speed photocathode gating for generation III image intensifier applications,” Proc. SPIE 5079, 212–220 (2003).

R. X. Zhang, Y. H. Tang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Partial gating image intensifier based on liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

X. S. Yang, Y. H. Tang, K. Liu, H. C. Liu, H. Y. Gao, Q. Li, R. X. Zhang, N. Ye, Y. Liang, and G. X. Zhao, “Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity,” Proc. SPIE 7279, 27–32 (2009).

Other (6)

Y. Liang, Y. H. Tang, K. Liu, H. Y. Gao, N. Ye, R. X. Zhang, X. S. Yang, G. X. Zhao, and Q. Li, “A partial imaging system by liquid crystal with single lens reflex,” Chinese patent, No.200910022963.0 (2009).

E. Lueder, Liquid Crystal Displays: Addressing schemes and electro-optical effects, (John Wiley & Sons, 2010) Chap. 6, p.107–109.

Parameters of Sony LCX029, http://www.datasheetcatalog.org/datasheet/sony/a6802816.pdf .

Y. H. Tang, Q. Li, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, G. X. Zhao, Y. Liang, and N. Ye, “A partial gating detector based on HTPS LC panel,” Chinese patent, ZL200810232000.9 (2010).

Y. H. Tang, G. X. Zhao, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, and N. Ye, “A large latitude of civil digital photography by liquid crystal and its preparation method,” Chinese patent, ZL200810232003.2 (2010).

Y. H. Tang, R. X. Zhang, K. Liu, H. C. Liu, X. S. Yang, H. Y. Gao, Y. Liang, Q. Li, N. Ye, and G. X. Zhao, “Study of a part gating detector by LC auto-controlling light intensity,” Chinese patent, ZL200810151198.8 (2010).

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Figures (12)

Fig. 1
Fig. 1

The structure sketch of partially light-controlled imaging system. It includes lens, HTPS TFT-LCD, optical fiber taper, CCD sensor, LCD driving module, FPGA and shell.

Fig. 2
Fig. 2

(a) The actual device of partially light-controlled imaging system, and (b) The actual device of HTPS TFT-LCD of Sony LCX029 with diagonal of 2.3 cm, resolution of 1024 × 768 and twist angle of 90°.

Fig. 3
Fig. 3

The principle of partially light-controlled imaging system. In the first frame image processing, the CCD plays a role in metering. But in the second frame image processing the CCD plays a role in real imaging because of the image collected with partially light-controlled.

Fig. 4
Fig. 4

The experiment for calibration of the relationship between light transmittance and gray level. The parallel light, produced by the collimator, can reach the luminometer through the LCD. The computer enters the gray-level which ranges from 0 to 255 in step of 15 into the LCD driver, and the light transmittance varies with the gray-level.

Fig. 5
Fig. 5

Variations of TFT-LCD transmittance with respect to gray levels. The star symbols are the experimental data while the solid line is the fitting curve.

Fig. 6
Fig. 6

The experiment for validation of the partially light-controlled imaging system. The object—a pig model, at bright light of more than 105lx, is imaged with the Canon EOS 400D camera, which is used to replace the combination of CCD and optical fiber taper as shown in Fig. 1.

Fig. 7
Fig. 7

(a) The exposure image without any signal on the LCD; (b) the corresponding grayscale image controlled by the FPGA and computer; and (c) the image of second shot where many details such as the words on the belly of pig model have been recovered. The histograms below show that the image contrast has been alleviated.

Fig. 8
Fig. 8

A prototype of the partially light-controlled imaging system. The optimized digital-analog conversion and power modules have been introduced into the prototype based on the structure in Fig. 2(a).

Fig. 9
Fig. 9

Comparisons of the images taken with altering the electronic shutter. (a) With 2-stop of electronic shutter; and (b) With 7-stop of electronic shutter. In (a), the girl and cat are too bright to be identified. In (b), some details of the cat appear while the girl becomes too dark to be seen.

Fig. 11
Fig. 11

Comparisons of the images taken with the prototype of partially light-controlled imaging system. (a) With the max light transmittance of all pixels; and (b) With the appropriate light-control. By means of partial light-control, the cat becomes clear while most of the information of the girl is retained as shown in (b), and therefore the image contrast has been alleviated.

Fig. 10
Fig. 10

Comparisons of the images taken with adjusting AGC. (a) With H-stop of AGC; and (b) With L-stop of AGC. The girl in (a) is clear while the cat is partial exposure over. But in (b), the exposure part of the cat become clear but the girl almost disappears because of the light weakened seriously.

Fig. 12
Fig. 12

Comparisons of photographs of the license plate with headlights turned on at night. (a) The image taken by the WAT-231S2 CCD video camera without any auxiliary lighting; (b) The image taken with the shutter of 1/10000s with headlights; and (c) The image taken with our prototype with headlights. It is obvious that much better result in (c) are obtained with our prototype, and the license plate can be identified as “Shaan A EQ827”.

Equations (6)

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

T=12u2+cos2(π21+u2)1+u2
u=2dλ[ne(θ)no]
θ={0(VVc)π22arctan[exp|VVcV0|](V>Vc)
1ne2(θ)=cos2θno2+sin2θne2
T=-1 .7029×10-10G5+7.874346×108G41.029578111×105G3+7.5558022135×104G21.278619419131×102G+1 .32710197006453
R2=1(YY)2(YY¯)2

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