<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>wavelets | Georgios Exarchakis</title><link>https://exarchakis.net/tag/wavelets/</link><atom:link href="https://exarchakis.net/tag/wavelets/index.xml" rel="self" type="application/rss+xml"/><description>wavelets</description><generator>Wowchemy (https://wowchemy.com)</generator><language>en-us</language><copyright>© 2026</copyright><lastBuildDate>Wed, 03 Dec 2025 17:14:00 +0000</lastBuildDate><image><url>https://exarchakis.net/media/icon_hua2ec155b4296a9c9791d015323e16eb5_11927_512x512_fill_lanczos_center_2.png</url><title>wavelets</title><link>https://exarchakis.net/tag/wavelets/</link></image><item><title>Solid Harmonic Wavelet Bispectrum for Image Analysis</title><link>https://exarchakis.net/publication/solid-harmonic-wavelet-bispectrum-for-image-analysis/</link><pubDate>Wed, 03 Dec 2025 17:14:00 +0000</pubDate><guid>https://exarchakis.net/publication/solid-harmonic-wavelet-bispectrum-for-image-analysis/</guid><description/></item><item><title>Kymatio</title><link>https://exarchakis.net/post/kymatio/</link><pubDate>Tue, 02 Apr 2019 13:37:24 +0200</pubDate><guid>https://exarchakis.net/post/kymatio/</guid><description>&lt;p>&lt;a href="https://kymat.io" target="_blank" rel="noopener">Kymatio&lt;/a> is a Python module for computing wavelet and scattering transforms.&lt;/p>
&lt;p>It is built on top of PyTorch, but also has a fast CUDA backend via cupy and skcuda.&lt;/p>
&lt;p>Use kymatio if you need a library that:&lt;/p>
&lt;ul>
&lt;li>integrates wavelet scattering in a deep learning architecture,&lt;/li>
&lt;li>supports 1-D, 2-D, and 3-D wavelets, and runs seamlessly on CPU and GPU hardware.&lt;/li>
&lt;li>A brief intro to wavelet scattering is provided in User Guide. For a list of publications see Publications.&lt;/li>
&lt;/ul>
&lt;h3>Quick Start&lt;/h3>
On Linux or macOS, open a shell and run the instruction of [kymatio](https://github.com/kymatio/kymatio).
&lt;p>In the Python intepreter, you may then call:&lt;/p>
&lt;div class="highlight">&lt;pre style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4">&lt;code class="language-python" data-lang="python">&lt;span style="color:#f92672">import&lt;/span> kymatio&lt;/code>&lt;/pre>&lt;/div>
&lt;p>which should run without error if the package has been correctly installed.&lt;/p>
&lt;h3>Apply 2D scattering to a 32x32 random image&lt;/h3>
The following code imports ```torch``` and the ```Scattering2D``` class, which implements the 2D scattering transform. It then creates an instance of this class to compute the scattering transform at scale ```J = 2``` of a ```32x32``` image consisting of Gaussian white noise:
&lt;div class="highlight">&lt;pre style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4">&lt;code class="language-python" data-lang="python">&lt;span style="color:#f92672">import&lt;/span> torch
&lt;span style="color:#f92672">from&lt;/span> kymatio &lt;span style="color:#f92672">import&lt;/span> Scattering2D
scattering &lt;span style="color:#f92672">=&lt;/span> Scattering2D(J&lt;span style="color:#f92672">=&lt;/span>&lt;span style="color:#ae81ff">2&lt;/span>, shape&lt;span style="color:#f92672">=&lt;/span>(&lt;span style="color:#ae81ff">32&lt;/span>, &lt;span style="color:#ae81ff">32&lt;/span>))
x &lt;span style="color:#f92672">=&lt;/span> torch&lt;span style="color:#f92672">.&lt;/span>randn(&lt;span style="color:#ae81ff">1&lt;/span>, &lt;span style="color:#ae81ff">1&lt;/span>, &lt;span style="color:#ae81ff">32&lt;/span>, &lt;span style="color:#ae81ff">32&lt;/span>)
Sx &lt;span style="color:#f92672">=&lt;/span> scattering(x)
&lt;span style="color:#66d9ef">print&lt;/span>(Sx&lt;span style="color:#f92672">.&lt;/span>size())&lt;/code>&lt;/pre>&lt;/div>
&lt;p>This should output:&lt;/p>
&lt;div class="highlight">&lt;pre style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4">&lt;code class="language-python" data-lang="python">torch&lt;span style="color:#f92672">.&lt;/span>Size([&lt;span style="color:#ae81ff">1&lt;/span>, &lt;span style="color:#ae81ff">1&lt;/span>, &lt;span style="color:#ae81ff">81&lt;/span>, &lt;span style="color:#ae81ff">8&lt;/span>, &lt;span style="color:#ae81ff">8&lt;/span>])&lt;/code>&lt;/pre>&lt;/div>
&lt;p>This corresponds to 81 scattering coefficients, each corresponding to an 8x8 image.&lt;/p>
&lt;p>Check out the &lt;a href="https://www.kymat.io/userguide.html#user-guide" target="_blank" rel="noopener">User Guide&lt;/a> for more scattering transform examples.&lt;/p></description></item><item><title>Kymatio: Scattering Transforms in Python</title><link>https://exarchakis.net/publication/kymatio-scattering-transforms-in-python/</link><pubDate>Fri, 28 Dec 2018 00:00:00 +0000</pubDate><guid>https://exarchakis.net/publication/kymatio-scattering-transforms-in-python/</guid><description>&lt;!-- More detail can easily be written here using *Markdown* and $\rm \LaTeX$ math code. --></description></item><item><title>Solid harmonic wavelet scattering for predictions of molecule properties</title><link>https://exarchakis.net/publication/solid-harmonic-wavelet-scattering-for-predictions-of-molecule-properties/</link><pubDate>Thu, 28 Jun 2018 00:00:00 +0000</pubDate><guid>https://exarchakis.net/publication/solid-harmonic-wavelet-scattering-for-predictions-of-molecule-properties/</guid><description>&lt;!-- # More detail can easily be written here using *Markdown* and $\rm \LaTeX$ math code. --></description></item><item><title>Solid Harmonic Wavelet Scattering: Predicting Quantum Molecular Energy from Invariant Descriptors of 3D Electronic Densities</title><link>https://exarchakis.net/publication/solid-harmonic-wavelet-scattering-predicting-quantum-molecular-energy-from-invariant-descriptors-of-3d-electronic-densities/</link><pubDate>Tue, 21 Nov 2017 00:00:00 +0000</pubDate><guid>https://exarchakis.net/publication/solid-harmonic-wavelet-scattering-predicting-quantum-molecular-energy-from-invariant-descriptors-of-3d-electronic-densities/</guid><description>&lt;!-- # More detail can easily be written here using *Markdown* and $\rm \LaTeX$ math code. --></description></item></channel></rss>