Direct reconstruction from 2-D wavelet coefficients

`Y = upcoef2(O,X,`

* 'wname'*,N,S)

Y = upcoef2(O,X,Lo_R,Hi_R,N,S)

Y = upcoef2(O,X,

`'wname'`

Y = upcoef2(O,X,Lo_R,Hi_R,N)

Y = upcoef2(O,X,

`'wname'`

Y = upcoef2(O,X,

`'wname'`

Y = upcoef2(O,X,Lo_R,Hi_R)

Y = upcoef2(O,X,Lo_R,Hi_R,1)

`upcoef2`

is a two-dimensional
wavelet analysis function.

`Y = upcoef2(O,X,`

computes
the * 'wname'*,N,S)

`N`

-step reconstructed coefficients of matrix `X`

and
takes the central part of size `S`

. `'wname'`

`wfilters`

for more information. If `O = 'a'`

, approximation coefficients are
reconstructed; otherwise if `O = 'h'`

(`'v'`

or `'d'`

,
respectively), horizontal (vertical or diagonal, respectively) detail
coefficients are reconstructed. `N`

must be a strictly
positive integer.

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

For `Y = upcoef2(O,X,Lo_R,Hi_R,N,S)`

is the reconstruction low-pass filter and `Hi_R`

is
the reconstruction high-pass filter.

`Y = upcoef2(O,X,`

or * 'wname'*,N)

```
Y
= upcoef2(O,X,Lo_R,Hi_R,N)
```

returns the computed result
without any truncation. `Y = upcoef2(O,X,`

is
equivalent to * 'wname'*)

`Y = upcoef2(O,X,``'wname'`

,1)

.`Y = upcoef2(O,X,Lo_R,Hi_R)`

is equivalent
to `Y = upcoef2(O,X,Lo_R,Hi_R,1)`

.

% 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 db4. [c,s] = wavedec2(X,2,'db4'); % Reconstruct approximation and details % at level 1, from coefficients. % This can be done using wrcoef2, or % equivalently using: % % Step 1: Extract coefficients from the % decomposition structure [c,s]. % % Step 2: Reconstruct using upcoef2. siz = s(size(s,1),:); ca1 = appcoef2(c,s,'db4',1); a1 = upcoef2('a',ca1,'db4',1,siz); chd1 = detcoef2('h',c,s,1); hd1 = upcoef2('h',chd1,'db4',1,siz); cvd1 = detcoef2('v',c,s,1); vd1 = upcoef2('v',cvd1,'db4',1,siz); cdd1 = detcoef2('d',c,s,1); dd1 = upcoef2('d',cdd1,'db4',1,siz);

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