Wavelet Toolbox |

Single-level reconstruction of 2-D wavelet decomposition

**Syntax **

**Description **

`upwlev2`

is a two-dimensional wavelet analysis function.

`[NC,NS,cA] = upwlev2(C,S,`

'

'*wname*`)`

performs the single-level reconstruction of wavelet decomposition structure `[C,S]`

giving the new one `[NC,NS]`

, and extracts the last approximation coefficients matrix cA.

`[C,S]`

is a decomposition at level `n = size(S,1)-2`

, so `[NC,NS]`

is the same decomposition at level `n`

-1 and cA is the approximation matrix at level `n`

.

'

' is a string containing the wavelet name, *wname*`C`

is the original wavelet decomposition vector, and `S`

the corresponding bookkeeping matrix (for detailed storage information, see `wavedec2`

).

Instead of giving the wavelet name, you can give the filters.

For `[NC,NS,cA] = upwlev2(C,S,`

Lo_R,Hi_R`)`

, Lo_R is the reconstruction low-pass filter and Hi_R is the reconstruction high-pass filter.

**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 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

**See Also**

```
idwt2, upcoef2, wavedec2
```

upwlev | wavedec |