pylops.signalprocessing.DWT2D

class pylops.signalprocessing.DWT2D(dims, dirs=(0, 1), wavelet='haar', level=1, dtype='float64')[source]

Two dimensional Wavelet operator.

Apply 2D-Wavelet Transform along two directions dirs of a multi-dimensional array of size dims.

Note that the Wavelet operator is an overload of the pywt implementation of the wavelet transform. Refer to https://pywavelets.readthedocs.io for a detailed description of the input parameters.

Parameters:
dims : tuple

Number of samples for each dimension

dirs : tuple, optional

Direction along which FFT is applied.

wavelet : str, optional

Name of wavelet type. Use pywt.wavelist(kind='discrete') for a list of available wavelets.

level : int, optional

Number of scaling levels (must be >=0).

dtype : str, optional

Type of elements in input array.
Raises:
ModuleNotFoundError

If pywt is not installed

ValueError

If wavelet does not belong to pywt.families

Notes

The Wavelet operator applies the 2-dimensional multilevel Discrete Wavelet Transform (DWT2) in forward mode and the 2-dimensional multilevel Inverse Discrete Wavelet Transform (IDWT2) in adjoint mode.

Attributes:
shape : tuple

Operator shape

explicit : bool

Operator contains a matrix that can be solved explicitly (True) or not (False)

Methods

__init__(self, dims[, dirs, wavelet, level, …]) Initialize this LinearOperator.
adjoint(self) Hermitian adjoint.
apply_columns(self, cols) Apply subset of columns of operator
cond(self, \*\*kwargs_eig) Condition number of linear operator.
conj(self) Complex conjugate operator
div(self, y[, niter]) Solve the linear problem \(\mathbf{y}=\mathbf{A}\mathbf{x}\).
dot(self, x) Matrix-matrix or matrix-vector multiplication.
eigs(self[, neigs, symmetric, niter]) Most significant eigenvalues of linear operator.
matmat(self, X) Matrix-matrix multiplication.
matvec(self, x) Matrix-vector multiplication.
rmatmat(self, X) Adjoint matrix-matrix multiplication.
rmatvec(self, x) Adjoint matrix-vector multiplication.
todense(self) Return dense matrix.
transpose(self) Transpose this linear operator.

Examples using pylops.signalprocessing.DWT2D