# isorthwfb

## Syntax

## Description

returns true if the two-channel filter bank formed from the lowpass (scaling) filter
`tf`

= isorthwfb(`Lo`

)`Lo`

satisfies the necessary and sufficient conditions to be a
two-channel orthonormal perfect reconstruction (PR) wavelet filter bank.
`isorthwfb`

forms the highpass (wavelet) filter using the `qmf`

function: `Hi = qmf(Lo)`

.

For a list of the necessary and sufficient conditions that the lowpass and highpass filters must satisfy, see Orthonormal Perfect Reconstruction Wavelet Filter Bank.

uses the highpass (wavelet) filter `tf`

= isorthwfb(`Lo`

,`Hi`

)`Hi`

to determine whether
`Lo`

and `Hi`

jointly satisfy the necessary and
sufficient conditions to be a two-channel orthonormal PR wavelet filter bank.

`isorthwfb`

assumes that `Lo`

and
`Hi`

form an orthogonal quadrature mirror filter pair. To return
accurate results, ensure that you provide either both analysis filters or both synthesis
filters.

## Examples

## Input Arguments

## Output Arguments

## More About

## Algorithms

Before performing the orthogonality checks, the `isorthwfb`

function
normalizes the lowpass filter so its coefficients sum to √2.

## References

[1] Strang, Gilbert, and Truong
Nguyen. *Wavelets and Filter Banks*. Rev. ed. Wellesley, Mass:
Wellesley-Cambridge Press, 1997.

[2] Burrus, C. S., Ramesh A. Gopinath,
and Haitao Guo. *Introduction to Wavelets and Wavelet Transforms: A
Primer*. Upper Saddle River, N.J: Prentice Hall, 1998.

## Extended Capabilities

## Version History

**Introduced in R2022b**