ls2filt

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

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    This version of ls2filt will be removed in a future release. Use the new version of ls2filt and liftingScheme. For more information, see Version History.

    Syntax

    [LoD,HiD,LoR,HiR] = ls2filt(LS)

    Description

    [LoD,HiD,LoR,HiR] = ls2filt(LS) returns the four filters LoD, HiD, LoR, and HiR associated with the lifting scheme LS.

    example

    Examples

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    Open Live Script

    Obtain the lifting scheme associated with the db2 wavelet.

    LS = liftwave("db2")
    LS=4×3 cell array
    {'d'     }    {[       -1.7321]}    {[       0]}
    {'p'     }    {[-0.0670 0.4330]}    {[       1]}
    {'d'     }    {[             1]}    {[      -1]}
    {[1.9319]}    {[        0.5176]}    {0×0 double}

    Visualize the lifting scheme.

    displs(LS);
    LS = {...                                         
'd'             [ -1.73205081]              [0]   
'p'             [ -0.06698730  0.43301270]  [1]   
'd'             [  1.00000000]              [-1]  
[  1.93185165]  [  0.51763809]              []    
};

    Obtain the filters associated with the lifting scheme.

    [LoD,HiD,LoR,HiR] = ls2filt(LS)
    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

    Get the db2 filters using the wfilters function. Check the equality.

    [LoDref,HiDref,LoRref,HiRref] = wfilters("db2")
    LoDref = 1×4

   -0.1294    0.2241    0.8365    0.4830


    HiDref = 1×4

   -0.4830    0.8365   -0.2241   -0.1294


    LoRref = 1×4

    0.4830    0.8365    0.2241   -0.1294


    HiRref = 1×4

   -0.1294   -0.2241    0.8365   -0.4830

    Input Arguments

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    Lifting scheme, specified as a cell array. The format of LS is identical to the format of the output of liftwave.

    Note

    liftwave is no longer recommended and will be removed in a future release. Use liftingScheme.

    Data Types: cell

    Output Arguments

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

    Data Types: double

    Wavelet reconstruction filters, returned as a pair of even-length real-valued vectors. LoR is the lowpass reconstruction filter, and HiR is the highpass reconstruction filter. See wfilters for additional information.

    Data Types: double

    Version History

    Introduced before R2006a

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    See Also

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