Scilab Wavelet Toolbox Function
Last update : Feburary 2006
idwt2 - two dimensional inverse fast discrete wavelet transform
Calling Sequence
-
a0=idwt(cA,cH,cV,cD,wavename,row,col,[extension_method])
Parameters
-
cA
: Approximation Coefficient
-
cH
: Horizontal Detail Coefficient
-
cV
: Vertical Detail Coefficient
-
cD
: Diagonal 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
-
row
: Reconstructed Matrix Row Length
-
col
: Reconstructed Matrix Column 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 Matrix
Description
This function performs two 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
-->img=rand(64,64);
-->[cA,cH,cV,cD]=dwt2(img,'db2','symh');
-->a0=idwt2(cA,cH,cV,cD,'db2',64,64,'symh');
-->sum(abs(a0-img))
ans =
4.693E-13
See Also
dwt
,
idwt
,
dwt2