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lp2LS

Laurent polynomials to lifting steps and normalization factors

    Description

    example

    [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

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    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

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

    • "o" — Orthogonal wavelet

    • "b" — Biorthogonal wavelet

    Data Types: char | string

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

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

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

    • "analysis" — Analysis factorization

    • "synthesis" — Synthesis factorization

    Output Arguments

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    Lifting steps, returned as an array of liftingStep structures.

    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