2-D wavelet reconstruction
X = waverec2(C,S,wname)
X = waverec2(C,S,Lo_R,Hi_R)
X = waverec2(C,S,wname)
X = appcoef2(C,S,wname,0)
X = waverec2(C,S, performs a multilevel
wavelet reconstruction of the matrix wname)X based on the wavelet
decomposition structure [C,S]. For detailed storage information, see
wavedec2. wname
is a character vector or string scalar specifying the wavelet. See wfilters for more information.
Instead of specifying the wavelet name, you can specify the filters.
X = waverec2(C,S,Lo_R,Hi_R), Lo_R is
the reconstruction low-pass filter
Hi_R is the reconstruction high-pass
filter.
waverec2 is the inverse function of wavedec2 in the sense that the abstract statement
waverec2(wavedec2(X,N,
returns wname),wname)X.
X = waverec2(C,S, is equivalent to
wname)X = appcoef2(C,S,.wname,0)
% The current extension mode is zero-padding (see dwtmode).
% Load original image.
load woman;
% X contains the loaded image.
% Perform decomposition at level 2
% of X using sym4.
[c,s] = wavedec2(X,2,'sym4');
% Reconstruct X from the wavelet
% decomposition structure [c,s].
a0 = waverec2(c,s,'sym4');
% Check for perfect reconstruction.
max(max(abs(X-a0)))
ans =
2.5565e-10
If C and S are obtained
from an indexed image analysis or a truecolor image analysis, X is
an m-by-n matrix or an m-by-n-by-3
array, respectively.
For more information on image formats, see the image and imfinfo reference
pages.