waverec2 (Wavelet Toolbox)

Multi-level 2-D wavelet reconstruction.

X = waverec2(C,S,'wname')
X = waverec2(C,S,Lo_R,Hi_R)

Description

waverec2 is a two-dimensional wavelet analysis function.

X = waverec2(C,S,'wname') performs a multi-level wavelet reconstruction of two-dimensional signal X based on the wavelet decomposition structure [C,S] (for detailed storage information, see wavedec2). 'wname' is a string containing the name of wavelet (see wfilters).

Instead of giving the wavelet name, you can give the filters. For
X = waverec2(C,S,Lo_R,Hi_R), Lo_R is the reconstruction low-pass filter and 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,'wname'),'wname') gets back to X.

Remarks

Note that X = waverec2(C,S,'wname') is equivalent to
X = appcoef2(C,S,'wname',0).

Examples

% 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(X-a0))

ans =
    1.9463e-10