基于小波去噪的T-ray图像复原

吴伟; 毕岗

红外与激光工程, 2005, 34 (5): 592, 网络出版: 2006-05-25

基于小波去噪的T-ray图像复原

Image restoration in T-ray imaging based on wavelet de-noising

论文大纲

吴伟 ¹毕岗 ²

作者单位

¹ 浙江大学,信息学院,信息与电子工程学系,浙江,杭州,310027

² 浙江大学,城市学院,信息与电子工程系,浙江,杭州,310015

T-ray图像小波去噪 1/f噪声广义交叉确认图像复原 T-ray imaging Wavelet de-noising l/f noise Generalized cross validation Image restoration

摘要

针对实时THz脉冲(T-ray)成像系统所成图像分辨率低、受1/f相关噪声干扰严重的特点,提出一种新的基于小波去噪的T-fay图像复原算法.对T-ray图像进行离散小坡变换后,先利用广义交叉确认估计出各个分辨率层的噪声阈值,然后对每个分辨率层的高频子带进行迭代去噪,最后对去噪后的T-ray图像采用Jasson-Van-Cittert算法进行复原处理以提高分辨率.实验结果表明,该方法在提高T-ray图像分辨率的同时,能显著地抑制THz成像系统的1/f相关噪声.创新之处在于以广义交叉确认作为T-ray图像中1/f噪声的估计方法,大幅度提高了图像信噪比(～5 dB),避免了噪声带来的复原算法中的不适定问题,达到较好的图像复原效果.

Abstract

In order to improve the spatial resolution and reduce l/f noise of real-time THz pulses （T- ray） imaging system, a new method based on wavelet de-nosing and Jasson-Van-Cittert （JVC） image restoration algorithm was presented. After making wavelet transform to a T-ray image, generalized cross validation （GCV） was used to estimate the optimal threshold and de-noising was done in the high frequency sub-bands respectively. The JVC image restoration algorithm was applied to the de-noised T-ray image for resolution improving. Experimental results show that this method can suppress l/f noise successfully and improve the resolution of T-ray image significantly.

参考文献

[1] . Imaging with terahertz waves[J]. Optics Letters, 1995, 20(16): 1716-1718.

[2] . T-ray imaging[J]. IEEE Journal of Selected Topics in Quantum Electronics, 1996, 2(3): 679-692.

[3] . Analysis of system tradeoff for terahertz imaging[J]. Microelectronics Journal, 1999, 31(7): 503-514.

[4] . THz near-field imaging[J]. Optics Communications, 1998, 150: 22-26.

[5] . Semiconductor dynamic aperture for near-fild terahertz wave imaging[J]. IEEE Journal on Selected Topics in Quantum Electronics, 2001, 7(4): 608-614.

[6] . Development of terahertz wave microscopes[J]. Infrared Physics and Technology, 2004, 45: 417-425.

[7] . Coherent terahertz radiation detection: direct comparison between free-space electro-optic sampling and antenna detection[J]. Applied Physics Letters, 1998, 73: 1604-1606.

[8] Gonzalez R C,Wintz P.Digital Image Processing [M]. New York:Addison -Wesley, 1977.221 -225.

[9] Stephane Mallat.A Wavelet Tour of Signal Processing [M].Carolina: Academic Press,1999.344-346.

[10] . Estimation of 1/f noise[J]. IEEE Transactions on Information Theory, 1998, 44(1): 32-46.

[11] . Generalization cross validation for wavelet thresholding[J]. Signal Process, 1997, 56: 463-479.

[12] Schildknecht C,Kleine-Ostmann T,Knohloch P,et al.Numerical image enhancement for THz time-domain spectroscopy[A].Terahertz Electronics Proceedings,IEEE Tenth International Confefence [C].USA: IEEE, 2002.57-160.

[13] Huang T S.Picture Pressing Digital Filtering [M]. London:Springer -Verlag, 1979.242-244.

吴伟, 毕岗. 基于小波去噪的T-ray图像复原[J]. 红外与激光工程, 2005, 34(5): 592. 吴伟, 毕岗. Image restoration in T-ray imaging based on wavelet de-noising[J]. Infrared and Laser Engineering, 2005, 34(5): 592.

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