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filt2ls

(To be removed) Transform quadruplet of filters to lifting scheme

    filt2ls will be removed in a future release. Use liftingScheme instead. For more information, see Compatibility Considerations.

    Description

    example

    LS = filt2ls(LoD,HiD,LoR,HiR) returns the lifting scheme LS associated with the four input filters LoD, HiD, LoR, and HiR that verify the perfect reconstruction condition.

    Examples

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    Obtain the filters associated with the db2 wavelet.

    [LoD,HiD,LoR,HiR] = wfilters('db2')
    LoD = 1×4
    
       -0.1294    0.2241    0.8365    0.4830
    
    
    HiD = 1×4
    
       -0.4830    0.8365   -0.2241   -0.1294
    
    
    LoR = 1×4
    
        0.4830    0.8365    0.2241   -0.1294
    
    
    HiR = 1×4
    
       -0.1294   -0.2241    0.8365   -0.4830
    
    

    Obtain the lifting scheme associated with the filters.

    LS = filt2ls(LoD,HiD,LoR,HiR);
    disp(LS)
     	 Wavelet               : 'custom' 
    	 LiftingSteps          : [3 × 1] liftingStep 
    	 NormalizationFactors  : [0.29886 3.346] 
    	 CustomLowpassFilter   : [  ] 
    
    
     Details of LiftingSteps :
                Type: 'predict'
        Coefficients: 0.5774
            MaxOrder: 0
    
                Type: 'update'
        Coefficients: [-0.4330 2.7990]
            MaxOrder: 0
    
                Type: 'predict'
        Coefficients: -0.3333
            MaxOrder: 1
    

    Input Arguments

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    Wavelet decomposition filters, specified as a pair of even-length real-valued vectors. LoD is the lowpass decomposition filter, and HiD is the highpass decomposition filter. The lengths of LoD and HiD must be equal. See wfilters for additional information.

    Data Types: double

    Wavelet reconstruction filters, specified as a pair of even-length real-valued vectors. LoD is the lowpass reconstruction filter, and HiD is the highpass reconstruction filter. The lengths of LoR and HiR must be equal. See wfilters for additional information.

    Data Types: double

    Output Arguments

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    Lifting scheme, returned as a liftingScheme object.

    Data Types: cell

    Version History

    Introduced before R2006a

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