# waverec2

2-D wavelet reconstruction

## Syntax

```X = waverec2(C,S,wname) X = waverec2(C,S,Lo_R,Hi_R) X = waverec2(C,S,wname) X = appcoef2(C,S,wname,0) ```

## Description

`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`. `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,wname),wname)` returns `X`.

`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 ```

## Tips

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.

## Extended Capabilities 