lp2LS

Laurent polynomials to lifting steps and normalization factors

Since R2021b

Syntax

[lsteps,k] = lp2LS(wavetype,LoRz,HiRz,factmode)

Description

[lsteps,k] = lp2LS(wavetype,LoRz,HiRz,factmode) returns the lifting scheme steps lsteps and normalization factors k associated with the Laurent polynomials LoRz and HiRz. wavetype specifies the wavelet type corresponding to the Laurent polynomials, and factmode specifies the factorization mode.

Examples

Obtain Lifting Scheme from Laurent Polynomials

Create a lifting scheme associated with the db2 wavelet.

wv = "db2";
lsw = liftingScheme(Wavelet=wv);

Obtain the Laurent polynomials associated with the wavelet, and then obtain the lifting steps and normalization factors associated with the Laurent polynomials.

[~,~,LoRz,HiRz] = wave2lp(wv);
[lsteps,k] = lp2LS("o",LoRz,HiRz,"s");

Create a lifting scheme using the lifting steps and normalization factors.

lscheme = liftingScheme(LiftingSteps=lsteps,NormalizationFactors=k)

lscheme = 
 	 Wavelet               : 'custom' 
	 LiftingSteps          : [3 × 1] liftingStep 
	 NormalizationFactors  : [3.3461 0.2989] 
	 CustomLowpassFilter   : [  ] 


 Details of LiftingSteps :
            Type: 'update'
    Coefficients: -0.5774
        MaxOrder: 0

            Type: 'predict'
    Coefficients: [-2.7990 0.4330]
        MaxOrder: 1

            Type: 'update'
    Coefficients: 0.3333
        MaxOrder: -1

Input Arguments

wavetype — Wavelet type

"o" | "b"

Wavelet type associated with the Laurent polynomials LoRz and HiRz, specified as one of:

• "o" — Orthogonal wavelet

• "b" — Biorthogonal wavelet

Data Types: char | string

LoRz — Laurent polynomial

laurentPolynomial object

Laurent polynomial associated with a lowpass filter, specified as a laurentPolynomial object.

HiRz — Laurent polynomial

laurentPolynomial object

Laurent polynomial associated with a highpass filter, specified as a laurentPolynomial object.

factmode — Factorization mode

"analysis" (default) | "synthesis"

Factorization mode of lifting steps and normalization factors, specified as one of:

• "analysis" — Analysis factorization

• "synthesis" — Synthesis factorization

Output Arguments

lsteps — Lifting steps

array of liftingStep structures

Lifting steps, returned as an array of liftingStep structures.

k — Normalization factors

real-valued vector

Normalization factors, returned as a 1-by-2 real-valued vector.

Data Types: double

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2021b