Wavelet Toolbox™

Lifting schemes information

Syntax

• lsinfo
  

Description

lsinfo displays the following information about lifting schemes. A lifting scheme LS is a N x 3 cell array. The N-1 first rows of the array are elementary lifting steps (ELS). The last row gives the normalization of LS.

Each ELS has this format:

• {type, coefficients, max_degree}
  

where type is 'p' (primal) or 'd' (dual), coefficients is a vector C of real numbers defining the coefficients of a Laurent polynomial P described below, and max_degree is the highest degree d of the monomials of P.

The Laurent polynomial P is of the form

P(z) = C(1)*z^d + C(2)*z^(d-1) + ... + C(m)*z^(d-m+1)

The lifting scheme LS is such that for

k = 1:N-1, LS{k,:} is an ELS, where

LS{k,1} is the lifting type 'p' (primal) or 'd' (dual).

LS{k,2} is the corresponding lifting filter.

LS{k,3} is the highest degree of the Laurent polynomial corresponding to the filter LS{k,2}.

LS{N,1} is the primal normalization (real number).

LS{N,2} is the dual normalization (real number).

LS{N,3} is not used.

Usually, the normalizations are such that LS{N,1}*LS{N,2} = 1.

For example, the lifting scheme associated with the wavelet db1 is

• LS = {...
        'd'         [    -1]    [0]
        'p'         [0.5000]    [0]
        [1.4142]    [0.7071]     []
       }
  

See Also
displs, laurpoly

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