MATLAB小波分析与应用实践

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waveinfo('db')
DBINFO Information on Daubechies wavelets. Daubechies Wavelets General characteristics: Compactly supported wavelets with extremal phase and highest number of vanishing moments for a given support width. Associated scaling filters are minimum-phase filters. Family Short name Order N Examples Daubechies db N strictly positive integer db1 or haar, db4, db15
Lo_D and Hi_D (Decomposition filters) If 'type' = 'd' Lo_R and Hi_R (Reconstruction filters) If 'type' = 'r' Lo_D and Lo_R (Low-pass filters) If 'type' = 'l' Hi_D and Hi_R (High-pass filters) If 'type' = 'h'
wavemngr('read')
% List initial wavelets families. ans = ========================== Meyer meyr DMeyer dmey Gaussian gaus Mexican_hat mexh Morlet morl Complex Gaussian cgau Shannon shan Frequency B-Spline fbsp Complex Morlet cmor ==========================
Wfilters函数 小波滤波器 • [Lo_D,Hi_D,Lo_R,Hi_R] = wfilters('wname') • [F1,F2] = wfilters('wname','type') • [Lo_D,Hi_D,Lo_R,Hi_R] = wfilters('wname') computes four filters associated with the orthogonal or biorthogonal wavelet named in the string 'wname'. • [F1,F2] = wfilters('wname','type') returns the following filters: • • • •
Haar Daubechies Symlets Coiflets BiorSplines ReverseBior
haar db sym coif bior rbio Nhomakorabea•
wavemngr('read',1)
ans = ================================== Haar haar ================================== Daubechies db -----------------------------db1 db2 db3 db4 db5 db6 db7 db8 db9 db10 db** ================================== Symlets sym -----------------------------sym2 sym3 sym4 sym5 sym6 sym7 sym8 sym** ================================== Coiflets coif -----------------------------coif1 coif2 coif3 coif4 coif5 ================================== BiorSplines bior -----------------------------bior1.1 bior1.3 bior1.5 bior2.2 bior2.4 bior2.6 bior2.8 bior3.1 bior3.3 bior3.5 bior3.7 bior3.9 bior4.4 bior5.5 bior6.8 ================================== ReverseBior rbio -----------------------------rbio1.1 rbio1.3 rbio1.5 rbio2.2 rbio2.4 rbio2.6 rbio2.8 rbio3.1 rbio3.3 rbio3.5 rbio3.7 rbio3.9 rbio4.4 rbio5.5 rbio6.8 ================================== ………
MATLAB小波分析与应用实践
Wavemngr函数 小波管理器 语法格式： • wavemngr('add',FN,FSN,WT,NUMS,FILE) • wavemngr('add',FN,FSN,WT,NUMS,FILE,B) • wavemngr('del',N) • wavemngr('restore') • wavemngr('restore',IN2) • OUT1 = wavemngr('read') • OUT1 = wavemngr('read',IN2) • OUT1 = wavemngr('read_asc')
Orthogonal yes Biorthogonal yes Compact support yes DWT possible CWT possible Support width 2N-1 Filters length 2N Regularity about 0.2 N for large N Symmetry far from Number of vanishing moments for psi N Reference: I. Daubechies, Ten lectures on wavelets CBMS, SIAM, 61, 1994, 194-202