Wavelet Toolbox |

Multilevel 2-D wavelet reconstruction

**Syntax **

**Description **

`waverec2`

is a two-dimensional wavelet analysis function.

`X = waverec2(C,S,`

'

'*wname*`)`

performs a multilevel wavelet reconstruction of the matrix `X`

based on the wavelet decomposition structure `[C,S]`

(for detailed storage information, see `wavedec2`

). '

' is a string containing the name of the wavelet (see *wname*`wfilters`

for more information).

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*`)`

would give back `X`

.

**Remarks**

Note that `X = waverec2(C,S,`

'

'*wname*`)`

is equivalent to `X = appcoef2(C,S,`

'

'*wname*`,0)`

.

**Examples**

% 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

**See Also**

```
appcoef2, idwt2, wavedec2
```

waverec | wbmpen |