Wavelet packet decomposition 2-D
T = wpdec2(X,N,wname,E,P)
T = wpdec2(X,N,wname)
T = wpdec2(X,N,wname,'shannon')
wpdec2 is a two-dimensional
wavelet packet analysis function.
T = wpdec2(X,N, returns a wavelet packet
T corresponding to the wavelet packet decomposition of the
X, at level
N, with the specified wavelet
wfilters for more information).
T = wpdec2(X,N, is equivalent to
T = wpdec2(X,N,.
E is a character vector or string scalar containing the type of entropy and
P is an optional parameter depending on the value of
wentropy for more information).
|Entropy Type Name (E)||Parameter (P)||Comments|
|Character vector or string scalar|
|No constraints on |
'user' option is historical and still
kept for compatibility, but it is obsoleted by the last option described
in the preceding table. The
FunName option does
the same as the
'user' option and in addition,
allows you to pass a parameter to your own entropy function.
wpdec for a more
complete description of the wavelet packet decomposition.
% The current extension mode is zero-padding (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)
When X represents an indexed image, X is an
When X represents a truecolor image, it is an
array, where each
represents a red, green, or blue color plane concatenated along the
Coifman, R.R.; M.V. Wickerhauser (1992), “Entropy-based 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.