PyWavelets - Wavelet Transforms in Python

PyWavelets is open source wavelet transform software for Python. It combines a simple high level interface with low level C and Cython performance.

PyWavelets is very easy to use and get started with. Just install the package, open the Python interactive shell and type:

>>> import pywt
>>> cA, cD = pywt.dwt([1, 2, 3, 4], 'db1')

Voilà! Computing wavelet transforms has never been so simple :)

Here is a slightly more involved example of applying a digital wavelet transform to an image:

import numpy as np
import matplotlib.pyplot as plt

import pywt

# Load image
original =

# Wavelet transform of image, and plot approximation and details
titles = ['Approximation', ' Horizontal detail',
          'Vertical detail', 'Diagonal detail']
coeffs2 = pywt.dwt2(original, 'bior1.3')
LL, (LH, HL, HH) = coeffs2
fig = plt.figure(figsize=(12, 3))
for i, a in enumerate([LL, LH, HL, HH]):
    ax = fig.add_subplot(1, 4, i + 1)
    ax.imshow(a, interpolation="nearest",
    ax.set_title(titles[i], fontsize=10)


Main features

The main features of PyWavelets are:

  • 1D, 2D and nD Forward and Inverse Discrete Wavelet Transform (DWT and IDWT)
  • 1D, 2D and nD Multilevel DWT and IDWT
  • 1D, 2D and nD Stationary Wavelet Transform (Undecimated Wavelet Transform)
  • 1D and 2D Wavelet Packet decomposition and reconstruction
  • 1D Continuous Wavelet Transform
  • Computing Approximations of wavelet and scaling functions
  • Over 100 built-in wavelet filters and support for custom wavelets
  • Single and double precision calculations
  • Real and complex calculations
  • Results compatible with Matlab Wavelet Toolbox (TM)

Getting help

Use GitHub Issues, StackOverflow, or the PyWavelets discussions group to post your comments or questions.


PyWavelets is a free Open Source software released under the MIT license.


If you use PyWavelets in a scientific publication, we would appreciate citations of the project:

Lee G, Gommers R, Wasilewski F, Wohlfahrt K, O’Leary A, Nahrstaedt H, and Contributors, “PyWavelets - Wavelet Transforms in Python”, 2006-, [Online; accessed 2018-MM-DD].