Single-level reconstruction of 2-D wavelet decomposition
[NC,NS,cA] = upwlev2(C,S,wname)
[NC,NS,cA] = upwlev2(C,S,Lo_R,Hi_R)
upwlev2 is a two-dimensional
wavelet analysis function.
[NC,NS,cA] = upwlev2(C,S, performs the
single-level reconstruction of wavelet decomposition structure
giving the new one
[NC,NS], and extracts the last approximation
[C,S] is a decomposition at level
= size(S,1)-2, so
[NC,NS] is the same
decomposition at level
the approximation matrix at level
wname is a character vector or string scalar specifying the wavelet,
C is the original wavelet decomposition vector, and
S the corresponding bookkeeping matrix (for detailed storage
Instead of giving the wavelet name, you can give the filters.
[NC,NS,cA] = upwlev2(C,S,Lo_R,Hi_R),
the reconstruction low-pass filter and
the reconstruction high-pass filter.
% 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 db1. [c,s] = wavedec2(X,2,'db1'); sc = size(c) sc = 1 65536 val_s = s val_s = 64 64 64 64 128 128 256 256 % One step reconstruction of wavelet % decomposition structure [c,s]. [nc,ns] = upwlev2(c,s,'db1'); snc = size(nc) snc = 1 65536 val_ns = ns val_ns = 128 128 128 128 256 256