Whether convolution followed by down sampling equals wavelet decomposition

3 次查看(过去 30 天)
I know that wavelet decomposition equals convolution followed by down sampling by two.I tried to test this on mat lab on haar wavelet. I write the below code and compared with the default wavedec command in mat lab. The code I wrote is shown below.
% clear all
clc
h=[0.7071 0.7071];% Haar scaling filter
g=[-0.7071 0.7071];%Haar wavelet filter
x=[1:10];% Input
h=fliplr(h);% h(-m)
g=fliplr(g);%g(-m)
s=conv(h,x);
s=downsample(s,2)
d=conv(g,x);
d=downsample(d,2)
[a L]=wavedec(x,1,'haar') % for comparison
if true
% code
end
After running this program I get ` s = 0.7071 3.5355 6.3639 9.1923 12.0207 7.0710. d = 0.7071 0.7071 0.7071 0.7071 0.7071 -7.0710 and the wavedec out put as a = 2.1213 4.9497 7.7782 10.6066 13.4350 -0.7071 -0.7071 -0.7071 -0.7071 -0.7071. L = 5 5 10`
I dont know why wavedec and my code gives different out puts, will any one help???

回答(0 个)

类别

Help CenterFile Exchange 中查找有关 Discrete Multiresolution Analysis 的更多信息

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by