复数小波理论及其在图像去噪与增强中的应用研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
非平稳信号的稀疏表示和高效处理算法是数学和信息科学研究的重要内容,其中,近年来建立起来的小波理论与算法已经成为信号稀疏表示的有效方法。但是,传统小波变换在处理信号和图像时存在平移敏感性和方向选择性弱等缺陷,因此,研究具有更好的近似平移不变性和奇异特征表示能力的新型小波变换,成为当前小波理论发展以及图像处理中非常重要的课题。由于图像获取方式的限制或在传输过程中受到干扰,通常导致观测的图像质量过低或被各种噪声所污染。图像去噪的主要目的是在保留图像原有重要信息的前提下降低或消除噪声,获得高质量的为人类视觉所接受的图像,从而为下一步的图像处理奠定基础。图像增强的目的是通过处理凸显原图像不够清晰的细节信息,使得处理后的图像更加便于人眼理解或机器识别。图像去噪和增强都是目前计算机视觉和图像处理领域最基本的且仍未很好解决的挑战性课题。
     针对传统离散小波变换(DWT,Discrete Wavelet Transform)的局限,本文深入研究了二元树复数小波变换(DT-CWT,Dual-Tree Complex Wavelet Transform)的相关性质,包括近似平移不变性、方向性和实现问题等,并在此基础上提出了构造二元树复数小波滤波器组的新算法;提出了一种新型复数小波变换—高密二元树离散小波变换(HD-DT DWT,Higher-Density Dual-Tree DWT),研究了其相关的性质及满足各种约束条件的滤波器组的构造方法;为更好的处理非平稳信号,初步研究了基于全变差模型和优化方法的信号和图像自适应分解问题;进一步深入研究了新型复数小波变换在图像去噪和增强中的应用,获得了比现有方法有显著改进的实验结果。
     本文的主要工作和创新如下:
     ■研究了二元树复数小波中双正交Hilbert变换对的构造。对线性相位双正交小波的构造和二元树复数小波变换的相关性质进行了充分而详尽的研究,在此基础上提出了利用参数化技术和最优化方法构造二元树复数小波变换中的Hilbert变换对的方法。这种滤波器设计的优点在于,对参数作适当的调节就能得到有理系数的二元树复数小波滤波器组,对于提高变换速度和效率、降低计算复杂度都有显著意义。
     ■针对传统DWT的缺陷,提出了高密度二元树离散小波变换这一新型复数小波变换的概念,系统深入的研究了高密度二元树离散小波变换的性质和构造方法,利用分数阶延迟滤波器、谱因子分解等技术构造出了具有紧支撑、消失矩、较高阶的光滑性、近似Hilbert变换对关系、中间尺度等优良性质的小波函数,为信号和图像等高维数据的分析提供了一种新的变换方法。
     ■作为用小波变换对信号和图像进行分解的一种推广,本文还初步研究了基于优化方法的信号和图像自适应分解问题,根据信号自适应的得到其低分辨率近似和重构滤波器,使得重构信号与原信号之间的误差最小。为提高所得近似图像的视觉质量,我们进一步将全变差模型引入自适应分解方法中,为对信号或图像进行自适应分解提供了一种新思路。
     ■基于理论研究的结果,进一步深入探讨了新型复数小波变换在图像去噪和增强中的应用,提出了三种基于DT-CWT的图像去噪新算法:(ⅰ)复数小波变换域利用系数尺度间和尺度内相关性的图像去噪算法;(ⅱ)基于局部参数的二元树复数小波域隐马尔可夫树(HMT,Hidden Markov Tree)模型图像去噪;(ⅲ)复数小波域高斯尺度混合(GSM,Gaussian Scale Mixture)模型去噪。这些方法充分利用了复数小波变换的优良性质及其系数分布的统计规律,实验表明,在简化计算复杂度、提高计算效率的同时获得了比现有相关去噪算法有显著改进的的去噪效果。另外,我们还提出了一种基于尺度间和尺度内相关性SURE方法的正交小波阈值去噪方法,解决了最近提出的正交小波域去噪算法对含较多纹理的图像处理效果不佳的缺陷,成为目前非冗余小波变换域效果最好的去噪算法。
     ■最后,我们还探讨了结合新型复数小波变换和最优视觉表示的统计特性的图像增强问题,提出了两种图像增强算法:(ⅰ)基于双密度二元树离散小波变换(DD-DT DWT,Double-Density Dual-Tree DWT)和视觉表示的图像增强算法,取得了非常好的视觉效果;(ⅱ)基于二元树复数小波和视觉表示的噪声图像增强算法,较好的缓解了带噪声图像增强中噪声抑制和细节保护之间的矛盾。
Efficient sparse representation and processing of unstable signal are the main contents in mathematics and information science. Recently, the Discrete Wavelet Transform (DWT) has become efficient in the sparse representation of unstable signal and also is a powerful tool for signal and image processing. It, however, has some disadvanges, including, (1) It is shift sensitive because the input signal shift generates unpredictable changes in DWT coefficients; (2) It suffers from poor directionality because DWT coefficients reveal merely three spatial orientations; (3) It lacks of the phase information that accurately dscribes non-stationary signal behavior; that undermine its usage in many applications. Therefore, there is a strong motivation to study new types of wavelet transforms with better shift invariance and directionality. Due to the imperfection of image acquisition systems and transmission channels, the observed images are often in low-quality or degraded by noise. The goal of image denoising is to remove the noise while retaining as much as possible the important features (edges) and obtain acceptable image for vision. The image enhancement algorithms are to process a given image so the results are better than original image for their applications or objectives. Noise elimination and image enhancement are still the most fundamental, widely studied, and largely unsolved problems in computer vision and image processing.
     To overcome the disadvantages of the traditional DWT, this thesis mainly focus on two new types of complex wavelet transform: the dual-tree complex wavelet transform (DT-CWT) and the higher density dual tree DWT. The properties of the DT-CWT such as approximate shift-invariance, directionality and implementation issue are carefully investigigated. Furthermore, a new algorithm to construct wavelet filterbank of the DT-CWT is presented. At the same time, a new complex wavelet transform - the higher denstiy dual tree DWT is introduced and the corresponding characteristics are studies and a design procedure to obtain finite impulse response (FIR) filters that satisfy the numerous constraints imposed is developed. To better process the non-stational signal, the total variation and optimization based schemes for signal and image adaptive decomposition are preliminarily studied. Some classical applications of the proposed complex wavelet transforms are also further studies such as image denoising and enhancement. Results of experiments show that the proposed new algorithms perform better than the now existing methods.
     The main achievements in this paper are as follow:
     First, an approach for designing biorthogonal DT-CWT filters is proposed; where the two related wavelets pairs form approximate Hilbert transform pairs. Different from the existing design techniques, the two wavelet filterbanks obtained here are both of linear phases. By adjusting the parameters, wavelet fitlers with rational coefficients may be achieved, which can speed up the DT-CWT effectively.
     Then, to overcome the disadavanges of the DWT, we introduce the higher-density dual-tree DWT, which is a DWT that combines the higher-density DWT and the DT-CWT, each of which has its own characteristics and advantages. The transform corresponds to a new family of dyadic wavelet tight frames based on two scaling functions and four distinct wavelets. We develop a design procedure to obtain finite impulse response (FIR) filters that satisfy the numerous constraints imposed. This design procedure employs a fractinal-delay allpass filters, spectral factorization and the solutions have vanishing moments, compact support, a high degree of smootheness, intermediate scales, approximate Hilbert transform properties, and are nearly shift-invariant.
     In addition, we investigate the problem of adaptive deocompositon of the signal and image, the optimization method and total variation model are employed in the process. Experimental results show that the proposed methods are effective to a wide range of signals and images; when compared to the fixed wavelet bases method, the produced reconstruct images with our adaptive method are with better PSNR and visual quality.
     Based on the theory above, to address the problems of the image denoising and enhancement, we investigate the image denosing and enhancement in the new types of complex wavelet transform domain in detail. Three new image denoising algorithms based on the DT-CWT are proposed: (i) a new locally adaptive image denoising method, which exploits the intra-scale and inter-scale depencencies in the DT-CWT domain; (ii) a new non-tranining compelx wavelet Hidden Markov Tree (CHMT) model, which is based on the DT-CWT and a fast parameters estimation technique; (iii) a new denoising algorithm based on the Gaussian scale mixture (GSM) of the coefficients of the DT-CWT. These methods exploit the properties of the DT-CWT and the statistics of the coefficients and the obtained better denoising performances while reducing the computational complexity. At the same time, we introduce an effective integration of the intrascale correlations within the interscale SURE based orthonormal wavelet thresholding, which can solve the problem of the interscale method that is not very effective for those images that have substantial high-frequency contents.
     In addition, we also investigate the image enhancement based on the new types of wavelet transform and the statistical characters of visual representation and propose two new method of image enhancement: (i) a novel method for image enhancement, which exploits the properties of the double-density dual-tree DWT and the statistical characters of visual representation; (ii) a new method for noisy image enhancement, which is based on the GSM model of the DT-CWT coefficients and the combination of the DT-CWT and the statistical characters of visual representation, and can optimize the contrast of image features of while minimizing image denoise.
引文
[1]Blahut R.E.Fast Algorithms for Digital Signal Processing.New York:Addision-Wesley,Reeding,Mass.;1984.
    [2]Mallat S.A Wavelet Tour of Signal Processing.Academic Press,2th edition;1999.
    [3]Nussbaumer H.J.Fast Fourier Transfrom and Convolution Algorithms.2nd edition,New York:Springer-Verlag;1981.
    [4]蒋增荣,曾泳泓.快速算法.长沙:国防科技大学出版社;1993.
    [5]Chui C.K.An Introduction to Wavelets.Academic Press;1992.
    [6]Daubechies I.Ten Lectures on Wavelets.SIAM:Philadelphia;1992.
    [7]Christopoulos C.JEPG-2000 Verification Model 3.0(technical description).In.1998.
    [8]Pennebaker W.B.,Mitchell J.L.JEPG:Still Image Compression Standard.In.1993.
    [9]高文(著).多媒体数据压缩技术.北京:电子工业出版社;1994.
    [10]Crossman A.,Morlet J.Decomposition of Hardy functions into square integrable wavelets of constant shape.SIAM J Math Anal 1984;15(4):723-736.
    [11]Mallat S.Multiresolution approximation and wavelets.Trans of American Math Soc 1989;315:69-88.
    [12]Mallat S.A theory for multiresolution signal decompostion:the wavelet representation.IEEE Trans on PAMI 1989;674-693.
    [13]Meyer Y.Wavelets:algorithms and applications.SIAM;1993.
    [14]Daubechies I.Orthonormal bases of compactly supported wavelets.Comm Pure Applied Math 1988;XLI(41):909-996.
    [15]Fernandes F.C.A.Directional,Shift-insensitive,Complex Wavelet Transforms with Controllable Redundancy.Rice University:2002.Ph.D.Thesis.
    [16]Strang G.Wavelets and dilation equations:A brief introduction.SIAM Review 1989;31(4):614-627.
    [17]Dragotti P.L.,Vetterli M.Wavelet footprints:Theory,algorithms,and applications.IEEE Trans on Signal Processing 2003;51(5):1306-1323.
    [18]Romberg J.,Wakin M.,Choi H.,Kingsbury N.,Baranuck R.G.A hidden Markov tree model for the complex wavelet transform.In.Rice ECE,Tech.Rep.;2002.
    [19] Romberg J., Choi H., Baranick R.G., Kingsbury N. Multiscale classification using complex wavelets and hidden Markov tree models. In: IEEE Int.Conf.Image Processing;2000.
    
    [20] Selesnick I.W., Baraniuk R.G., Kingsbury N. The dual-tree complex wavelet transform: A coherent framework for multiscale signal and image processing. In. 2005:123-151.
    
    [21] Granlund G.H., Knutsson H. Signal Processing for Computer Vision. Kluwer Academic Publishers; 1995.
    
    [22] Beylkin G., Torresani B. Implementation of operators via filter banks: Hardy wavelets and autocorrelation shell. Applied and Computational Harmonic Analysis 1996; 3: 164-185.
    
    [23] Mallat S. Zero-crossings of a wavelet transform. IEEE Trans on Inform Theory 1991; 37(4): 1019-1033.
    
    [24] Beylkin G. On the representation of operators in bases of compactly supported wavelets. SIAM J Numer Anal 1992; 29(6): 1716-1740.
    
    [25] Guo H. Theory and applications of the shift-invariant, time-varying and undecimated wavelet transform. Rice University, Houston, TX: 1995. Master thesis.
    
    [26] Liang J., Parks T.W. A translation invariant wavelet representation algorithm with applications. IEEE Trans on Signal Processing 1996; 44(2): 225-232.
    
    [27] Benno S.A., Moura J.M.F. Scaling functions robust to translations. IEEE Trans on Signal Processing 1998; 46(12): 3269-3281.
    
    [28] Selesnick I.W., Sendur L. Iterated oversampled filter banks and wavelet frames.Wavelet Applications VII, Proceedings of SPIE 2000.
    
    [29] Simoncelli E.P., Freeman W.T., Adelson E.H., Heeger D.J. Shiftable multi-scale transform. IEEE Trans on Inform Theory 1992; 38(2): 587-607.
    
    [30] Magarey J. Motion estimation using complex wavelets. University of Cambridge:1997. PhD thesis.
    
    [31] Kingsbury N., Magarey J. Wavelet transforms in image processing. In: First European Conference on Signal Analysis and Prediction; 1997.
    
    [32] Kingsbury N. Image processing with complex wavelets. Phil Trans R Soc London A, Math Phys Sci 1999; 357(1760): 2543-2560.
    
    [33] Selesnick I.W. The design of Hilbert transform pairs of wavelet bases via the flat delay filter. In: IEEE Int. Conf. on Acoustic, Speech and Signal Processing (ICASSP'01);2001.
    
    [34] Selesnick I.W. Hilbert transform pairs of wavelet bases. IEEE Signal Processing Letters 2001;8(6):170-173.
    [35]王红霞.基于滤波器组的新型小波理论及其应用研究.国防科学技术大学:2004.博士学位论文.
    [36]Bamberger R.H.,Smith M.J.T.A filter bank for the directional decomposition of images:Theory and design.IEEE Trans on Signal Processing 1992;40(4):882-893.
    [37]Park S-I.,Smith M.J.T.,Mersereau R.M.A new directional filter bank for image analysis and classification.In:IEEE Int.Conf.Acoust.,Speech,Signal Processing;1999.
    [38]Do M.,Vettedi M.Pyramidal directional filter banks and curvelets.In 2001.
    [39]Donoho D.L.Wedgelets:nearly-minimax estimation of edges.Ann Statist 1999;27:353-382.
    [40]Candes E.J.Ridgelets:theory and applications.Stanford University:1998.PhD thesis.
    [41]Donoho D.L.Orthonormal ridgelets and linear singularities.SIAM Journal on Mathametical Analysis 2000;31(5):1062-1099.
    [42]Candes E.J.,Donoho D.L.Curvelets,multiresolution representation,and scaling laws.In:A.Aldroubi,A.F.Laine,M.A.Unser(eds.).Proc.SPIE 4119;2000.
    [43]Candes E.J.,Donoho D.L.Curvelets - A surprisingly effective nonadaptive representation for objects with ediges,curves and surfaces.In:L.L.Schumaker et al (ed.).Vanderbilt University Press,Nashville,TN;1999.
    [44]焦李成,谭山同,图像的多尺几何分析:回顾和展望.电子学报 2003;31(12A):1975-1981.
    [45]焦李成,孙强.多尺度变换域图像的感知与识别:进展和展望,计算机学报2006;29(2):177-193.
    [46]Mallat S.,LePennec E.Bandelet Image Approximation and Compression.SIAM Journ of Multiscale Modeling and Simulation 2005;4(3):992-1039.
    [47]LePennec E.,Mallat S.Sparse Geometric Image Representation with Bandelets.IEEE Trans on Image Processing 2005;14(4):423-438.
    [48]Watson A.,Ahumada A.J.Model of human visual-motion sensing.Journal of Optical Society of America 1985;2(2):322-342.
    [49]Burns T.,Rogers S.,Ruck D.,Oxley M.Discrete,spatiotemporal,wavelet multiresolution analysis method for computing optical flow.Optical Engineering 1994;33(7):2236-2247.
    [50]Lawton W.Application of complex valued wavelet transforms to subband decomposition.IEEE Trans on Signal Processing 1993;41(12):3566-3568.
    [51] Lina J.M., Mayrand M. Complex Daubechies wavelets. Applied and Computational Harmonic Analysis 1995; 2: 219-229.
    
    [52] Zhang X-P., Desai M., Peng Y-N. Orthogonal complex filter banks and wavelets: some properties and design. IEEE Trans on Signal Processing 1999; 47(4): 1039-1048.
    
    [53] Cohen A., Ryan R.D. Wavelets and multiscale signal processing. London:Chapman and Hall; 1995.
    
    [54] Choi H., Romberg J., Baraniuk R.G., Kingsbury N. A hidden Markov tree modeling of complex wavelet transform. In: IEEE Int. Conf. Acoust, Speech, Signal Processing; 2000.
    
    [55] Rivaz P.D., Kingsbury N. Complex wavelet features for fast texture image retrieval. In: IEEE Int. Conf. Image Processing; 1999.
    
    [56] Reeves T.H., Kingsbury N. Prediction of coefficients from coarse to fine scales in the complex wavelet transform. In: IEEE Int. Conf. Acoust. Speech, Signal Processing;2000.
    
    [57] Vidakovic B., Lozoya C.B. On time-dependent wavelet denoising. IEEE Trans on Signal Processing 1998; 46(9): 2549-2551.
    
    [58] Olashausen B.A., Field D.J. Natural image statistics and efficient coding.Network:Computation in Neural Systems 1996; 7: 333-339.
    
    [59] Coifman R.R, Donoho D. Translation invariant denoising. In. Dep. Of Statics,Stanford University; 1995.
    
    [60] Donoho D.L., Johnstone I.M. Adapting to unknown smoothness via wavelet shrinkage. J Amer Statist Assoc 1995; 90(432): 1200-1224.
    
    [61] Donoho D.L., Johnstone I.M. Ideal spatial adaptation via wavelet shrinkage.Biometrika 1994; 81: 425-455.
    
    [62] Chen S.S., Donoho D.L., Saunder M.A. Atomic decomposition by basis pursuit.SIAM Journal on Scientific Computing 1999; 20(1): 33-61.
    
    [63] Mallat S., Zhang Z. Matching pursuits with time-frequency dictionaries. IEEE Trans on Signal Processing 1993; 41(12): 3397-3415.
    
    [64] Crouse M.S., Nowak R.D., Baraniuk R.G. Wavelet-based signal processing using Hidden Markov models. IEEE Trans on Signal Processing 1998; 46(4): 886-902.
    
    [65] Abramovich F., Sapatinas T., Silverman B. Wavelet thresholding via a Bayesian approach. J Roy Stat Soc B 1998; 60: 725-749.
    
    [66] Vidakovic B. Nonlinear wavelet shrinkage with Bayes rules and Bayes factors. J Amer Statist Assoc 1998; 93: 173-179.
    [67] Chang S.G., Yu B., Vetterli M. Spatially adaptive wavelet thresholding with context modeling for image denoising. IEEE Trans on Image Processing 2000; 9(9):1522-1531.
    
    [68] Chang S.G., Yu B., Vetterli M. Adaptive Wavelet Thresholding for Image Denoising and Compression. IEEE Trans on Image Processing 2000; 9(9): 1532-1546.
    
    [69] Shan Z., Aviyente S. Image denoising based on wavelet co-occurrence matrix. In:IEEE Int.Conf.Acoust., Speech, Signal Processing 05; 2005.
    
    [70] Zhang X-P., Desai M.D. Adaptive denoising based on SURE risk. IEEE Signal Processing Letters 1998; 5(10): 265-267.
    
    [71] Zhang X-P., Desai M.D. Nonlinear adaptive noise suppression based on wavelet transform. In: IEEE Int.Conf.Acoust., Speech, Signal Processing (ICASSP); 1998.
    
    [72] Starck J.-L., Murtagh F. Astronomical image and signal processing: Looking at noise, information and scales. IEEE Signal Processing Magazine 2001; 18(2): 30-40.
    
    [73] Vetterli M. Wavelets, approximation, and compression. IEEE Signal Processing Magazine 2001; 18(5): 59-73.
    
    [74] Skodras A., Christopoulos C, Ebrahimi T. The JPEG 2000 still image compression standard. IEEE Signal Processing Magazine 2001; 18(5): 36-58.
    
    [75] Cohen A., Daubechies I. Biorthogonal bases of compactly supported wavelets. Communications Pure and Appiled Mathematics 1992; XLV: 485-560.
    
    [76] Sweldens W. The lifting scheme: A custom-design construction of biothogonal wavelets. Applied and Comput Harmonic Anal 1996; 3(2): 186-200.
    
    [77] Daubechies I., Sweldens W. Factoring wavelet transforms into lifting steps.Journal of Fourier Anaysis and Application 1998; 4(3): 245-267.
    
    [78] Sweldens W. The lifting scheme: a second generation wavelets. SIAM J Math Anal 1998; 29(2): 511-546.
    
    [79] Strang G. Wavelets and filter banks. In. Cambridge: MA: Wellesley; 1996.
    
    [80] Wei D., Tian J., Wells Jr.R.O. A new class of biorthogonal wavelet systems for image transform coding. IEEE Trans on Image Processing 1998; 7: 1000-1013.
    
    [81] Tay D.B.H. Rationalizing coefficients of popular biorthogonal wavelet filters.IEEE Transactions on Circuits and Systems for Video Technology 2000; 10(6):998-1005.
    
    [82] Liang D.L., Cheng L.Z., Zhang Z.H. The general construction of wavelet filters via lifting scheme and its application in image coding. Optical Engineering 2003; 43(7):1949-1955.
    [83] Vaidyanathan P.P. Multirate Systems and Filter Banks. Englewood Cliffs, NJ,Prentice Hall; 1993.
    
    [84] DeVore R. Non-linear approximation. In. Cambridge Unviversity Press; 1998:51-150.
    
    [85] Malvar R. Is there life after JPEG2000 and H.264? In. Plenary talk at the Picture Coding Symposium; 2004.
    
    [86] Candes E.J., Donoho D.L. New tight frames of curvelets and optimal representations of objects with C2 singularities. In. Tech. rep., Standford University, 37;2002.
    
    [87] Candes E.J., Donoho D.L. Continuous curvelet transform: discretization and frames. In, 2003-31 ed. Dept. of Statistics, Stanford Unviversity: Stanford Unviversity;2003.
    
    [88] Donoho D.L., Vetterli M., DeVore R. Data compression and harmonic analysis.IEEE Trans on Inform Theory 1998; 44(6): 2435-2476.
    
    [89] Starck J.-L., Candes E.J., Donoho D.L. The curvelet transform for image denoising. IEEE Trans on Image Processing 2002; 11(6): 131-141.
    
    [90] Starck J.-L., Candes E.J., Donoho D.L. Very high quality image restoration by combining wavelets and curvelets. In: A.Aldroubi, A.F.Laine, M.A.Unser (eds.). Proc.SPIE 4478; 2001.
    
    [91] Starck J.-L., Elad M., Donoho D.L. Image decomposition via the combination of sparse representations and a variational approach. IEEE Trans on Image Processing 2005; 14(10): 1570-1582.
    
    [92] Burt P.J., Adelson E.H. The laplacian pyramid as a compac image code. IEEE Trans on Communications 1983; 31(4): 532-540.
    
    [93] LePennec E., Mallat S. Image compression with geometrical wavelets. In 2000;Los Alamitors.
    
    [94] Papoulis A. Signal Analysis. New York: McGraw-Hill; 1977.
    
    [95] Kingsbury N. The dual-tree complex wavelet transform: A new technique for shift invariance and directional filters. In: 8th IEEE DSP Workshop; 1998.
    
    [96] Kingsbury N. Complex wavelets for shift invariant analysis and filtering of signals.Appl Comput Harmonic Anal 2001; 10(3): 234-253.
    
    [97] Yu R., Ozkaramanli H. Hilbert transform pairs of orthogonal wavelet bases:Necessary and sufficient condition. IEEE Trans on Signal Processing 2005; 53(12):4723-4725.
    
    [98] Ozkaramanli H., Yu R. On the phase condition and its solution for Hilbert transform pairs of wavelet bases. IEEE Trans on Signal Processing 2003; 51(12):3293-3294.
    
    [99] Yu R., Ozkaramanli H. Hilbert transform pairs of biorthogonal wavelet bases. IEEE Trans on Signal Processing 2006; 54(6): 2119-2125.
    
    [100] Kingsbury N. A dual-tree complex wavelet transform with. improved orthogonality and symmetry properties. In: IEEE Int.Conf. Image Processing; 2000.
    
    [101] Selesnick I.W. The design of approximate Hilbert transform pairs of wavelet bases. IEEE Trans on Signal Processing 2002; 50(5): 1304-1314.
    
    [102] Thiran J.P. Recursive digital filters with maximally flat group delay. IEEE Trans Circuit Theory 1971; 18(6): 659-664.
    
    [103] Romberg J., Choi H., Baraniuk R.G. Bayesian tree-structured image modeling using wavelet-domain hidden Markov models. IEEE Trans on Image Processing 2001;10(7): 1056-1068.
    
    [104] Sendur L., Selesnick I.W. Bivariate shrinkage functions for wavelet-based denoising exploiting inter-scale dependency. IEEE Trans on Signal Processing 2002;50(11): 2744-2756.
    
    [105] Sendur L., Selesnick I.W. Bivariate shrinkage with local variance estimation. IEEE Signal Processing Letters 2002; 9(12): 438-441.
    
    [106] Portilla J., Strela V. Image denoising using Gaussian scale mixtures in the wavelel domain. IEEE Trans on Image Processing 2003; 12(11): 1338-1351.
    
    [107] Wainwright M.J., Simoncelli E.P. Scale mixtures of Gaussians and the statistics of natural images. Adv Neural Information Processing Systems 2000; 12: 855-861.
    
    [108] Xiao Z.Y., Wen W., Peng S.L. A fast classification-based parameter estimation technique for wavelet domain HMT model. In: Advanced Concepts for Intelligent Vision Systems (ACIVS'04); 2004.
    
    [109] Crouse M.S., Nowak R.D., Baraniuk R.G. Wavelet-based statistical signal processing using hidden Markov models. IEEE Trans on Signal Processing 1998; 46(4):886-902.
    
    [110] Dempster A.P., Laird N.M., Rubin D.B. Maximum likelihood from incomplete data via the EM algorithm. J Royal Stat Soc 1977; 39: 1-38.
    
    [111] Yan F.X., Cheng L.Z., Wang H.X. The design of Hilbert transform pairs in dual-tree complex wavelel transform. Wavelet Analysis and Applications, Applied and Numerical Harmonic Anaysis 2007; 431-441.
    
    [112] Yan F.X., Cheng L.Z., Wang H.X. Higher-density Dual-tree Discrete Wavelet Transform. IET Signal Processing 2007; 1(3).
    [113]成礼智.离散与小波变换新型算法及其在图像处理中应用的研究.国防科技大学:2003.博士学位论文.
    [114]Burrus C.S.,Gopinath R.A.,Guo H.Introduction to Wavelets and Wavelet Transforms.Prentice Hall;1997.
    [115]Shensa M.J.The discrete wavelet transform:Wedding the a trous and Mallat algorithms.IEEE Trans on Signal Processing 1992;40(10):2464-2482.
    [116]Lang M.,Guo H.,Odegard J.E.,Burrus C.S.,Well JRO.Noise reduction using an undecimated discrete wavelet transform.IEEE Signal Processing Letters 1996;3(1):10-12.
    [117]Xiong Z.,Orchard M.T.,Zhang Y.-Q.A deblocking algorithm for JPEG compressed images using overcomplete wavelet representations.IEEE Trans on Circuits Syst Video Technol 1997;7(2):433-437.
    [118]Wang Y.-P.,Wu Q.,Castleman K.,Xiong Z.Chromosome image enhancement using multiscale differential operators.IEEE Trans on Medical Imaging 2003;22(5):685-693.
    [119]Selesnick I.W.The double-density DWT.In:Petrosian A.A.,Meyer F.G.(eds.),Wavelets in Signal and Image Analysis:From Theory to Practice.Boston,MA:Kluwer Academic Publishers;2001.
    [120]Selesnick I.W.A Higher-density Discrete Wavelet Transform.IEEE Trans on Signal Processing 2006;54(8):3039-3048.
    [121]Selesnick I.W.The double-density dual-tree DWT.IEEE Trans on Signal Processing 2004;52(5):1304-1314.
    [122]Unser M.Wavelet theory demystified.IEEE Trans on Signal Processing 2003;51(2):470-483.
    [123]Tewfilk A.H.,Sinha D.,Jorgensen P.On the optimal choice of a wavelet for signal representation.IEEE Trans on Inform Theory 1992;38(2):747-765.
    [124]Coifman R.R,Wickerhauser M.V.Entropy-based algorithm for best basis selection.IEEE Trans on Inform Theory 1992;38(2):713-718.
    [125]Huang N.E.,Shen Z.,Long S.R.The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis.Proc R Soc Lond A 1998;454:903-995.
    [126]Liu Z.X.,Peng S.L.Boundary processing of Bidimensional EMD using texture synthesis.IEEE Signal Processing Letters 2005;12(1):33-36.
    [127]Rudin L.I.,Osher S.,Fatemi E.Nonlinear total variation based noise removal algorithms.Physica D 1992;60:259-268.
    [128]Chambolle A.An algorithm for total variation minimization and applications.Journal of Mathematical Imaging and Vision 2004;20:89-97.
    [129]Steidl G.,Weickert J.,Brox T.,Mrzek P.On the equivalence of soft wavelet shrinkage,total variation diffusion,total variation regularization,and sides.In,26 ed.Department of Mathematics,University of Bremen,Gemany;2003.
    [130]Yan F.X.,Cheng L.Z.Image denoising exploiting inter- and intra- scale dependency in complex wavelet domain.Chinese Optic Letters 2007;5(3):156-159.
    [131]Yan F.X.,Peng S.L.,Cheng L.Z.A new dual-tree complex wavelet hidden Markov tree model for image denoising.IET Electronic Letters 2007;46(17).
    [132]Yan F.X.,Cheng L.Z.Complex wavelet domain hidden Markov tree model with localized parameters for image denoising.In:2007 IEEE International Conference on Image Processing;2007.
    [133]严奉霞,成礼智.基于复方向小波变换和视觉表示的图像增强.国防科技大学学报2006;28:53-57.
    [134]严奉霞,成礼智,彭思龙.复数小波域的高斯尺度混合模型图像降噪.中国图形图像学报2007.
    [135]Liu J.,Moulin P.Information-theoretic analysis of interscale and intrascale dependencies between image wavelet coefficients.IEEE Trans on Image Processing 2001;10(10):1647-1658.
    [136]Simoncelli E.P.Modeling the joint statistics of images in the wavelet domain.In:SPIE 44th Annual Meeting;1999.
    [137]Chen Y.,Han C.Adaptive wavelet threshold for image denoising.IEE Electronics Letters 2005;41(10):586-587.
    [138]Donoho D.L.Denoising by soft-thresholding.IEEE Trans on Inform Theory 1995;41:613-627.
    [139]王红霞,成礼智,吴翊.基于复数小波变换增强带噪声图像的空间自适应增强方法.计算机辅助设计与图形学学报2005;17(9):1911-1916.
    [140]Luisier F.,Blu T.,Unser M.A new SURE approach to image denoising:interscale orthonormal wavelet thresholding.IEEE Trans on Image Processing 2007;16(3).
    [141]Stein C.Estimation of the mean of a multivariate normal distribution.Ann Statist 1981;9:1135-1151.
    [142]Pizurica A.,Philips W.Estimating the probability of the presence of a signal of interest in multiresolution single- and multiband image denoising.IEEE Trans on Image Processing 2006;15(3):645-665.
    [143] Gonzales R.C., Woods R.E. Digital Image Processing. MA: Addision-Wesley;1995.
    
    [144] Greenspan H., Anderson C.H., Akber S. Image enhancement by nonlinear extrapolations in frequency space. IEEE Trans on Image Processing 2000; 9(6):1035-1048.
    
    [145] Sakellaropoulos P., Costaridou L., Panayiotakis G. A wavelet-based spatially adaptive method for mammographic contrast enhancement. Physics in Medicine Biology 2003; 48(6): 783-803.
    
    [146] Velde K.V. Multi-scale color image enhancement. In 1999.
    
    [147] Dippel S., Stahl M., Wiemker R., Blaffert T. Multiscale contrast enhancement for radiographies: Laplacian pyramid versus fast wavelet transform. IEEE Trans on Medical Imaging 2002; 21(4): 343-353.
    
    [148] Starck J.-L., Murtagh F., Candes E.J., Donoho D.L. Gray and color image contrast enhancement by the curvelet transform. IEEE Trans on Image Processing 2003;12(6): 706-717.
    
    [149] Huang K.Q., Wu Z.Y., Wang Q. Image enhancement based on the statistics of visual representation. Image and Vision Computing 2005; 23: 51-57.
    
    [150] Jobson D., Rahman Z., Woodell G.A. The statistics of visual representation.Visual Information Processing XI, Proc SPIE 2002.
    
    [151] Han B. On dual wavelet tight frames. Appl Comput Harmonic Anal 1997; 40:380-413.
    
    [152] Daubeches I., Han B. Pairs of dual wavelet frames from any two refinable functions. Constr Approx 2004.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700