wfilters小波滤波器

wfilters

小波滤波器

语法

[Lo_D,Hi_D,Lo_R,Hi_R] = wfilters('wname')
[F1,F2] = wfilters('wname','type')

描述

[Lo_D,Hi_D,Lo_R,Hi_R] = wfilters('wname') 计算'wname'里的正交和双正交小波的四个滤波器。

以下是这四个滤波器

• Lo_D, the decomposition low-pass filter

• Hi_D, the decomposition high-pass filter

• Lo_R, the reconstruction low-pass filter

• Hi_R, the reconstruction high-pass filter

'wname'允许使用的正交和双正交小波如下：

小波族

小波

Daubechies

'db1' or 'haar', 'db2', ... ,'db10', ... , 'db45'

Coiflets

'coif1', ... , 'coif5'

Symlets

'sym2', ... , 'sym8', ... ,'sym45'

Discrete Meyer

'dmey'

Biorthogonal

'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'

Reverse Biorthogonal

'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'

[F1,F2] = wfilters('wname','type') 返回一下滤波器:

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'

例子

% 设置小波名. wname = 'db5';% 计算给定小波的四个滤波器 %  [Lo_D,Hi_D,Lo_R,Hi_R] = wfilters(wname); subplot(221); stem(Lo_D); title('Decomposition low-pass filter'); subplot(222); stem(Hi_D); title('Decomposition high-pass filter'); subplot(223); stem(Lo_R); title('Reconstruction low-pass filter'); subplot(224); stem(Hi_R); title('Reconstruction high-pass filter'); xlabel('The four filters for db5')% 结果如下图%