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1. 中国科学院长春光学精密机械与物理研究所, 吉林, 长春, 130022
2. 吉林大学, 吉林, 长春, 130022
3. 长春海关技术部,吉林 长春,130031
收稿日期:2001-09-17,
修回日期:2002-01-31,
网络出版日期:2002-04-15,
纸质出版日期:2002-04-15
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王波波, 来忠信, 黄廉卿, 王旭超. 基于多尺度隐马尔可夫模型的CR影像降噪方法研究[J]. 光学精密工程, 2002,(2): 188-193
WANG Bo-bo, LAI Zhong-xin, HUANG Lian-qing, WANG Xu-chao. MHMM-based computed radiography image-denoising method[J]. Editorial Office of Optics and Precision Engineering, 2002,(2): 188-193
在CR成像过程中不可避免的要引入各种干扰和噪声
只有弄清干扰图像信息的各种噪声来源、特征及其与信号的相互关系
才能有效地将之消除.在分析CR成像系统的基础上
文章指出影响CR图像质量的噪声主要是固有噪声和X线量子噪声
在统计规律上它们分别服从高斯分布和泊松分布.本文针对CR的固有噪声从小波系数的统计规律出发
根据固有噪声的特点
结合混合高斯模型描述小波系数的统计特征
采用两个状态的隐马尔可夫模型描述小波系数在尺度之间的相关性和依赖性
用最大期望值( EM)算法估计隐马尔可夫模型在各个尺度上的参数
然后按照尺度大小逐级对小波系数进行维纳滤波
最后是小波逆变换恢复图像.文章最后还给出了实验结果
并与其它降噪算法进行了比较.
In the process of computed radiography imaging
a lot of noises will be brought into the system. Therefore
only by knowing their resources
characteristics and relationship with signals
can the authors smooth them. On the basis of analyzing the computed radiography system in detail
the authors point out that there are two kinds of noises affecting the quality of a computed radiography image: Gaussian white noise and Poisson noise. Firstly
the statistical characteristics of wavelet coefficients and Gaussian white noise are summarized. Then
they are described with the mixture Gaussian model and hidden Markov model (HMM)
which can fit the dependency of wavelet coefficients between scales. Finally
the novel algorithm developed by the authors is compared with other wavelet-based denoising methods.
祁吉,高野正雄.计算机X线摄影[M].北京:人民卫生出版社, 1997.
巴雷特 H H,斯温德尔 W, 张万里,等.放射成像、图像形成、检测和处理的理论[M].北京:科学出版社,1988.
彭玉华.基于正交小波变换的图像去噪方法[J].中国图像图形学报,1999,4(8):677-679.
闫丽.光学子波用于图像处理[J].光学精密工程,2000,8(3):225-230.
刘光达.基于最小均方误差原理的医学X光影像滤波阈值选择[J].光学精密工程,2001,9(1):47-50.
Crouse M S, Nowak R D,Baraniuk R G.Wavelet-based statistical signal processing using hidden Markov models[A].IEEE Trans.Signal.Proc[C].1998, 46(4): 886-902.
Pesquet J C, Krim H,Hamman E.Bayesian approach to best basis selection[A].IEEE.Int.Conf.Acoust., Speech, Signal Proc[C].ICASSP,Atlanta,GA.1996.2634-2637.
Simoncelli E P,Adelson E H.Noise removal via Bayesian wavelet coring[A].IEEE.Int.Conf.Image Proc[C].ICIP.Step.1996.
Basseville M.Modeling and estimation of multiresolution stochastic processes[A].IEEE.Trans.Inform.Theory[C].1992, 38:3445-3462.
Luettgen M R, Karl W C,Willsky A S,et al.Multiscale representations of Markov random fields[A].IEEE.Trans.Signal Processing[C].1993, 41:3377-3395.
Rabiner L.A tutorial on hidden Markov models and selected applications in speech recognition[A].Proc.IEEE[C].1989, 77:257-285.
易克初.语音信号处理[M].北京:国防工业出版社, 2000.
Kuan D T, Sawchuk A A, Strand T C,et al.Adaptive noise smoothing filter for images with signal dependent noise[J].IEEE.Trans.Patt.Anal.Mach.Intell.1985, 7:165-177.
Yang C H,Su G.Adaptive filter for noise removal using wavelet transform[J].SPIE, 1995,2501:187-197.
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