addlift (Wavelet Toolbox)

Add lifting steps to lifting scheme

Syntax

LSN = addlift(LS,ELS)
LSN = addlift(LS,ELS,'begin')
LSN = addlift(LS,ELS,'end')

Description

LSN = addlift(LS,ELS) returns the new lifting scheme LSN obtained by appending the elementary lifting step ELS to the lifting scheme LS.

LSN = addlift(LS,ELS,'begin') prepends the specified elementary lifting step.

ELS is either a cell array (see lsinfo)

```
{TYPEVAL, COEFS, MAX_DEG}  
```

or a structure (see liftfilt)

```
struct('type',TYPEVAL,'value',LPVAL) 
```

with

```
LPVAL = laurpoly(COEFS, MAX_DEG)
```

LSN = addlift(LS,ELS,'end') is equivalent to addfilt(LS,ELS).

If ELS is a sequence of elementary lifting steps, stored in a cell array or an array of structures, then each of the elementary lifting steps is added to LS.

For more information about lifting schemes, see lsinfo.

Examples

% Start from the Haar wavelet and get the
% corresponding lifting scheme.
lshaar = liftwave('haar');

% Visualize the obtained lifting scheme.
displs(lshaar);

lshaar = {...                        
'd'             [ -1.00000000]  [0]  
'p'             [  0.50000000]  [0]  
[  1.41421356]  [  0.70710678]  []   
};                                   

% Add a primal ELS to the lifting scheme.
els = {'p',[-0.125 0.125],0};
lsnew = addlift(lshaar,els);
displs(lsnew);

lsnew = {...                                     
'd'             [ -1.00000000]              [0]  
'p'             [  0.50000000]              [0]  
'p'             [ -0.12500000  0.12500000]  [0]  
[  1.41421356]  [  0.70710678]              []   
};

See Also

liftfilt

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