I'm currently working on a project of mine where I have to use stationary wavelet transformation. I found a perfect way to do the transformation using wavelet toolbox of the Matlab. But since it is not free, I need to find a free function to do the exactly same thing SWT function of wavelet toolbox does.
What I Found
I found a Matlab functions package called WaveLab. They have defined a function called FWT_Stat to do Stationary wavelet transformation.
FWT_Stat -- stationary wavelet transform
Usage
StatWT = FWT_Stat(x,D,qmf)
Inputs
x array of dyadic length n=2^J
L degree of coarsest scale
qmf orthonormal quadrature mirror filter
Outputs
StatWT stationary wavelet transform table
formally same data structure as packet table
log_2(n)-D scales by n elements
Below shows information about SWT function from wavelet toolbox.
SWC = swt(X,N,'wname') computes the stationary wavelet decomposition of the signal X at level N, using 'wname'.
Problem
FWT_Stat function asks for 3 parameters and final parameter is orthonormal quadrature mirror filter
.But I couldn't find a way to add haar filter as the input for 3rd parameter .If I used SWT function from wavelet toolbox, all I have to do is add wavelet name (e.g: harr
) instead of wname
and swt function take care of all other things.
So my problem is, how can I add haar filter as the 3rd parameter for FWT_stat function on Matlab without Wavelet toolbox.
Or, Is there any alternative function (which is free) to do the exact same thing as SWT function from wavelet toolbox?