共查询到18条相似文献,搜索用时 125 毫秒
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周建锋 《数学的实践与认识》2014,(3)
研究由三元双正交插值尺度函数构造对应的双正交小波滤波器的矩阵扩充问题.当给定的一对三元双正交尺度函数中有一个为插值函数时,利用提升思想与矩阵多相分解方法,给出一类三元双正交小波滤波器的显示构造公式和一个计算实例.讨论了三元双正交小波包的的性质. 相似文献
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《数学的实践与认识》2015,(15)
基于双向加细小波函数和双向小波尺度函数,给出了矩阵伸缩的双向小波的定义;给出矩阵伸缩的多分辨分析,并给出矩阵伸缩的小波的正交条件,得到矩阵伸缩的双向小波包;并得到相关性质和结论. 相似文献
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针对二元小波框架在图像处理中应用的有效性,本文研究二元最小能量小波框架的特征.给出二元最小能量小波框架存在的充分必要条件,刻画了二元最小能量小波框架的特征.通过对加细函数和小波函数对应的面具函数进行多相分解,提出二元最小能量小波框架的分解与重构算法,并给出数值算例. 相似文献
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给出一类具有广义插值的正交多尺度函数的构造方法, 并给出对应多小波的显示构造公式. 证明了该文构造的多小波拥有与多尺度函数相同的广义基插值性.从而建立了多小波子空间上的采样定理. 最后基于该文提供的算法构造出若干具有广义基插值的正交多尺度函数和多小波. 相似文献
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Triebe利用Littlewood Paley分解将大多数函数空间分类成两类三指标的函数空间:Besov空间和Triebel Lizorkin空间;但Littlewood Paley 分解很难直接分析Sobolev空间L^p的插值空间Lorentz空间,也很难分析Triebel Lizorkin空间F^{α,q}_1的预备对偶空间和对偶空间.运用小波,作者给出这些空间一个统一刻画:Triebel Lizorkin Lorentz 空间,Besov Lorentz空间和F^{α,q}_1的预备对偶空间和对偶空间;另外也研究这些空间的三个性质. 相似文献
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L~2([0,1])的半正交小波基及其对偶小波基 总被引:1,自引:0,他引:1
本文从样条函数出发利用折叠法得到了L2([0,1])空间的两组相互对偶的半正交小波基,这两组小波基有显式表达式,并导出了他们的小波分解与重建算法.进一步,应用这些小波基给出了刻划高阶Holder空间的一个充分条件. 相似文献
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引入伸缩因子为a的多-尺度加细函数和平移不变子空间的概念.研究了多-尺度加细方程解存在的条件.特别地,给出这种方程的解是正交的充分必要条件.建立了多-尺度加细函数与两尺度加细函数之间的关系.并讨论了它们的一些性质.最后给出相应的构造算例. 相似文献
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A construction of interpolating wavelets on invariant sets 总被引:8,自引:0,他引:8
We introduce the concept of a refinable set relative to a family of contractive mappings on a metric space, and demonstrate how such sets are useful to recursively construct interpolants which have a multiscale structure. The notion of a refinable set parallels that of a refinable function, which is the basis of wavelet construction. The interpolation points we recursively generate from a refinable set by a set-theoretic multiresolution are analogous to multiresolution for functions used in wavelet construction. We then use this recursive structure for the points to construct multiscale interpolants. Several concrete examples of refinable sets which can be used for generating interpolatory wavelets are included.
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In this paper, we shall introduce and study a family of multivariate interpolating refinable function vectors with some prescribed interpolation property. Such interpolating refinable function vectors are of interest in approximation theory, sampling theorems, and wavelet analysis. In this paper, we characterize a multivariate interpolating refinable function vector in terms of its mask and analyze the underlying sum rule structure of its generalized interpolatory matrix mask. We also discuss the symmetry property of multivariate interpolating refinable function vectors. Based on these results, we construct a family of univariate generalized interpolatory matrix masks with increasing orders of sum rules and with symmetry for interpolating refinable function vectors. Such a family includes several known important families of univariate refinable function vectors as special cases. Several examples of bivariate interpolating refinable function vectors with symmetry will also be presented. 相似文献
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This short note presents four examples of compactly supported symmetric refinable componentwise polynomial functions: (i) a componentwise constant interpolatory continuous refinable function and its derived symmetric tight wavelet frame; (ii) a componentwise constant continuous orthonormal and interpolatory refinable function and its associated symmetric orthonormal wavelet basis; (iii) a differentiable symmetric componentwise linear polynomial orthonormal refinable function; (iv) a symmetric refinable componentwise linear polynomial which is interpolatory and differentiable. 相似文献
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In this note, we present a construction of interpolatory wavelet packets. Interpolatory wavelet packets provide a finer decomposition of the 2jth dilate cardinal interpolation space and hence give a better localization for an adaptive interpolation. This can lead to a more efficient compression scheme which, in turn, provides an interpolation algorithm with a smaller set of data for use in applications. 相似文献
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Compactly supported (bi)orthogonal wavelets generated by interpolatory refinable functions 总被引:7,自引:0,他引:7
This paper provides several constructions of compactly supported wavelets generated by interpolatory refinable functions.
It was shown in [7] that there is no real compactly supported orthonormal symmetric dyadic refinable function, except the
trivial case; and also shown in [10,18] that there is no compactly supported interpolatory orthonormal dyadic refinable function.
Hence, for the dyadic dilation case, compactly supported wavelets generated by interpolatory refinable functions have to be
biorthogonal wavelets. The key step to construct the biorthogonal wavelets is to construct a compactly supported dual function
for a given interpolatory refinable function. We provide two explicit iterative constructions of such dual functions with
desired regularity. When the dilation factors are larger than 3, we provide several examples of compactly supported interpolatory
orthonormal symmetric refinable functions from a general method. This leads to several examples of orthogonal symmetric (anti‐symmetric)
wavelets generated by interpolatory refinable functions.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Construction of biorthogonal wavelets from pseudo-splines 总被引:4,自引:0,他引:4
Pseudo-splines constitute a new class of refinable functions with B-splines, interpolatory refinable functions and refinable functions with orthonormal shifts as special examples. Pseudo-splines were first introduced by Daubechies, Han, Ron and Shen in [Framelets: MRA-based constructions of wavelet frames, Appl. Comput. Harmon. Anal. 14(1) (2003), 1–46] and Selenick in [Smooth wavelet tight frames with zero moments, Appl. Comput. Harmon. Anal. 10(2) (2001) 163–181], and their properties were extensively studied by Dong and Shen in [Pseudo-splines, wavelets and framelets, 2004, preprint]. It was further shown by Dong and Shen in [Linear independence of pseudo-splines, Proc. Amer. Math. Soc., to appear] that the shifts of an arbitrarily given pseudo-spline are linearly independent. This implies the existence of biorthogonal dual refinable functions (of pseudo-splines) with an arbitrarily prescribed regularity. However, except for B-splines, there is no explicit construction of biorthogonal dual refinable functions with any given regularity. This paper focuses on an implementable scheme to derive a dual refinable function with a prescribed regularity. This automatically gives a construction of smooth biorthogonal Riesz wavelets with one of them being a pseudo-spline. As an example, an explicit formula of biorthogonal dual refinable functions of the interpolatory refinable function is given. 相似文献
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Multivariate Compactly Supported Fundamental Refinable Functions, Duals, and Biorthogonal Wavelets 总被引:8,自引:0,他引:8
In areas of geometric modeling and wavelets, one often needs to construct a compactly supported refinable function φ which has sufficient regularity and which is fundamental for interpolation [that means, φ(0)=1 and φ(α)=0 for all α∈ Z s ∖{0}].
Low regularity examples of such functions have been obtained numerically by several authors, and a more general numerical scheme was given in [1]. This article presents several schemes to construct compactly supported fundamental refinable functions, which have higher regularity, directly from a given, continuous, compactly supported, refinable fundamental function φ. Asymptotic regularity analyses of the functions generated by the constructions are given.The constructions provide the basis for multivariate interpolatory subdivision algorithms that generate highly smooth surfaces.
A very important consequence of the constructions is a natural formation of pairs of dual refinable functions, a necessary element in constructing biorthogonal wavelets. Combined with the biorthogonal wavelet construction algorithm for a pair of dual refinable functions given in [2], we are able to obtain symmetrical compactly supported multivariate biorthogonal wavelets which have arbitrarily high regularity. Several examples are computed. 相似文献
Low regularity examples of such functions have been obtained numerically by several authors, and a more general numerical scheme was given in [1]. This article presents several schemes to construct compactly supported fundamental refinable functions, which have higher regularity, directly from a given, continuous, compactly supported, refinable fundamental function φ. Asymptotic regularity analyses of the functions generated by the constructions are given.The constructions provide the basis for multivariate interpolatory subdivision algorithms that generate highly smooth surfaces.
A very important consequence of the constructions is a natural formation of pairs of dual refinable functions, a necessary element in constructing biorthogonal wavelets. Combined with the biorthogonal wavelet construction algorithm for a pair of dual refinable functions given in [2], we are able to obtain symmetrical compactly supported multivariate biorthogonal wavelets which have arbitrarily high regularity. Several examples are computed. 相似文献