Scilab Wavelet Toolbox Function
Last update : Feburary 2006
idwt - one dimensional inverse fast discrete wavelet transform
Calling Sequence
-
a0=idwt(a,d,wavename,length,[extension_method])
Parameters
-
a
: Approximation coefficient
-
d
: Detail coefficient
-
wavename
: wavelet name
- 'haar': haar wavelet
- 'db1': daubechies 1 wavelet, same with haar
- 'db2': daubechies 2 wavelet
- 'db3': daubechies 3 wavelet
- 'db4': daubechies 4 wavelet
- 'db5': daubechies 5 wavelet
- 'db6': daubechies 6 wavelet
- 'db7': daubechies 7 wavelet
- 'db8': daubechies 8 wavelet
- 'db9': daubechies 9 wavelet
- 'db10': daubechies 10 wavelet
-
length
: Reconstructed Signal Length
-
extension_method
: Signal Extension Method, default is 'symh'
- 'zpd': zero padding method
- 'ppd': period extension method
- 'asymh': half asymmetric extension method
- 'asymw': whold asymmetric extension method
- 'symh': half symmetric extension method
- 'symw': whole symmetric extension method
- 'sp0': border value constant extension method
- 'sp1': border value linear extension method
-
a0
: Reconstructed Signal
Description
This function performs one dimensional inverse fast discrete wavelet transform and provides a reconstructed version of signal.
Extension method should be consistent with that of the decomposition
procedure. Detailed algorithm is fully described in the userguide.
Examples
-->sig=rand(1,64);
-->[a,d]=dwt(sig,'db2','zpd');
-->a0=idwt(a,d,'db2',64,'zpd');
-->e=sum(abs(a0-sig))
e =
3.469E-15
See Also
dwt
,
dwt2
,
idwt2