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fejerkorovkin

Fejér-Korovkin wavelet filters

Description

example

Lo = fejerkorovkin(wname) returns the Fejér-Korovkin scaling filter specified by wname. Valid entries for wname are 'fk4', 'fk6', 'fk8', 'fk14', 'fk18', and 'fk22'. For information on the Fejér–Korovkin filters, see Nielson[1].

Examples

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Construct and plot the Fejér-Korovkin (14) scaling function and wavelet.

Obtain the Fejér-Korovkin scaling filter and plot its 14 coefficients.

Lo = fejerkorovkin("fk14");
stem(Lo)
title("Scaling Filter Coefficients")

Use the scaling filter to obtain the wavelet filter and plot its coefficients.

Hi = qmf(Lo);
stem(Hi)
title("Wavelet Filter Coefficients")

wavefun provides an efficient way to construct and plot the scaling function and wavelet.

[phi,psi,xval] = wavefun("fk14");
tiledlayout(2,1)
nexttile
plot(xval,phi)
title("Scaling Function")
nexttile
plot(xval,psi)
title("Wavelet")

Input Arguments

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Name of desired Fejér-Korovkin scaling filter. The numeric value in each name is the number of Fejér-Korovkin filter coefficients. For example, if wname is 'fk14', Lo has 14 coefficients.

Output Arguments

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Scaling filter, returned as a vector.

References

[1] Nielsen, M. "On the construction and frequency localization of finite orthogonal quadrature filters." Journal of Approximation Theory. Vol. 108, Number 1, 2001, pp. 36–52.

Version History

Introduced in R2015b

See Also

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