Wavelet packet decomposition 2D
T = wpdec2(X,N,
'wname'
,E,P)
T = wpdec2(X,N,'wname'
)
T = wpdec2(X,N,wnam
,'shannon')
wpdec2
is a twodimensional
wavelet packet analysis function.
T = wpdec2(X,N,
returns
a wavelet packet tree 'wname'
,E,P)T
corresponding to the wavelet
packet decomposition of the matrix X
, at level N
,
with a particular wavelet ('wname'
, see wfilters
for more information).
T = wpdec2(X,N,
is
equivalent to 'wname'
)T = wpdec2(X,N,
.wnam
,'shannon')
E
is a string containing the type of entropy
and P
is an optional parameter depending on the
value of T
(see wentropy
for
more information).
Entropy Type Name (E)  Parameter (P)  Comments 

'shannon'  P is not used.  
'log energy'  P is not used.  
'threshold'  0 ≤ P  P is the threshold. 
'sure'  0 ≤ P  P is the threshold. 
'norm'  1 ≤ P  P is the power. 
'user'  string  P is a string containing the file name of
your own entropy function, with a single input X . 
STR  No constraints on P  STR is any other string except those used
for the previous Entropy Type Names listed above.

Note
The 
See wpdec
for a more
complete description of the wavelet packet decomposition.
% The current extension mode is zeropadding (see dwtmode). % Load image. load tire % X contains the loaded image. % For an image the decomposition is performed using: t = wpdec2(X,2,'db1'); % The default entropy is shannon. % Plot wavelet packet tree % (quarternary tree, or tree of order 4). plot(t)
Coifman, R.R.; M.V. Wickerhauser (1992), "Entropybased algorithms for best basis selection," IEEE Trans. on Inf. Theory, vol. 38, 2, pp. 713–718.
Meyer, Y. (1993), Les ondelettes. Algorithmes et applications, Colin Ed., Paris, 2nd edition. (English translation: Wavelets: Algorithms and Applications, SIAM).
Wickerhauser, M.V. (1991), "INRIA lectures on wavelet packet algorithms," Proceedings ondelettes et paquets d'ondes, 17–21 June, Rocquencourt, France, pp. 31–99.
Wickerhauser, M.V. (1994), Adapted wavelet analysis from theory to software Algorithms, A.K. Peters.