<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="X-UA-Compatible" content="IE=Edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Inverse Stationary Wavelet Transform — PyWavelets Documentation</title> <link rel="stylesheet" href="../_static/nature.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <script type="text/javascript" src="../_static/language_data.js"></script> <script async="async" type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/latest.js?config=TeX-AMS-MML_HTMLorMML"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within PyWavelets Documentation" href="../_static/opensearch.xml"/> <link rel="shortcut icon" href="../_static/favicon.ico"/> <link rel="index" title="Index" href="../genindex.html" /> <link rel="search" title="Search" href="../search.html" /> <link rel="next" title="Wavelet Packets" href="wavelet-packets.html" /> <link rel="prev" title="Stationary Wavelet Transform" href="swt-stationary-wavelet-transform.html" /> <meta name="description" content="PyWavelets is a scientific Python module for Wavelet Transform calculations."/> <meta name="keywords" content="PyWavelets, wavelets, Python, wavelet transform, discrete wavelet transform, dwt, idwt, swt, wavelet packets, stationary wavelet transform, pywt"/> <meta name="author" content="Filip Wasilewski"/> <meta name="Distribution" content="Global"/> <meta name="Robots" content="INDEX,FOLLOW"/> <script type="text/javascript"> (function ($) { $(document).ready(function () { $("#toggle-edit-info").click(function (e) { e.preventDefault(); $("#edit-info").toggle(); }); }); })(jQuery); </script> <script type="text/javascript"> var _gaq = _gaq || []; _gaq.push(['_setAccount', 'UA-3396395-3']); _gaq.push(['_trackPageview']); (function () { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); </script> </head><body> <div class="related" role="navigation" aria-label="related navigation"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" accesskey="I">index</a></li> <li class="right" > <a href="wavelet-packets.html" title="Wavelet Packets" accesskey="N">next</a> |</li> <li class="right" > <a href="swt-stationary-wavelet-transform.html" title="Stationary Wavelet Transform" accesskey="P">previous</a> |</li> <li><a href="../index.html">Home »</a></li> <li class="nav-item nav-item-1"><a href="index.html" accesskey="U">API Reference</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" role="main"> <div class="section" id="inverse-stationary-wavelet-transform"> <span id="ref-iswt"></span><h1>Inverse Stationary Wavelet Transform<a class="headerlink" href="#inverse-stationary-wavelet-transform" title="Permalink to this headline">¶</a></h1> <p>Inverse <a class="reference internal" href="swt-stationary-wavelet-transform.html#ref-swt"><span class="std std-ref">stationary wavelet transforms</span></a> are provided.</p> <p><strong>Note</strong>: These inverse transforms are not yet optimized for speed. Only, the n-dimensional inverse transform currently has <code class="docutils literal notranslate"><span class="pre">axes</span></code> support.</p> <div class="section" id="multilevel-1d-iswt"> <h2>Multilevel 1D <code class="docutils literal notranslate"><span class="pre">iswt</span></code><a class="headerlink" href="#multilevel-1d-iswt" title="Permalink to this headline">¶</a></h2> <dl class="function"> <dt id="pywt.iswt"> <code class="descclassname">pywt.</code><code class="descname">iswt</code><span class="sig-paren">(</span><em>coeffs</em>, <em>wavelet</em><span class="sig-paren">)</span><a class="headerlink" href="#pywt.iswt" title="Permalink to this definition">¶</a></dt> <dd><p>Multilevel 1D inverse discrete stationary wavelet transform.</p> <table class="docutils field-list" frame="void" rules="none"> <col class="field-name" /> <col class="field-body" /> <tbody valign="top"> <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><dl class="first docutils"> <dt><strong>coeffs</strong> <span class="classifier-delimiter">:</span> <span class="classifier">array_like</span></dt> <dd><p class="first">Coefficients list of tuples:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[(</span><span class="n">cAn</span><span class="p">,</span> <span class="n">cDn</span><span class="p">),</span> <span class="o">...</span><span class="p">,</span> <span class="p">(</span><span class="n">cA2</span><span class="p">,</span> <span class="n">cD2</span><span class="p">),</span> <span class="p">(</span><span class="n">cA1</span><span class="p">,</span> <span class="n">cD1</span><span class="p">)]</span> </pre></div> </div> <p class="last">where cA is approximation, cD is details. Index 1 corresponds to <code class="docutils literal notranslate"><span class="pre">start_level</span></code> from <code class="docutils literal notranslate"><span class="pre">pywt.swt</span></code>.</p> </dd> <dt><strong>wavelet</strong> <span class="classifier-delimiter">:</span> <span class="classifier">Wavelet object or name string</span></dt> <dd><p class="first last">Wavelet to use</p> </dd> </dl> </td> </tr> <tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><dl class="first last docutils"> <dt><strong>1D array of reconstructed data.</strong></dt> <dd></dd> </dl> </td> </tr> </tbody> </table> <p class="rubric">Examples</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pywt</span> <span class="gp">>>> </span><span class="n">coeffs</span> <span class="o">=</span> <span class="n">pywt</span><span class="o">.</span><span class="n">swt</span><span class="p">([</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">3</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">5</span><span class="p">,</span><span class="mi">6</span><span class="p">,</span><span class="mi">7</span><span class="p">,</span><span class="mi">8</span><span class="p">],</span> <span class="s1">'db2'</span><span class="p">,</span> <span class="n">level</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">pywt</span><span class="o">.</span><span class="n">iswt</span><span class="p">(</span><span class="n">coeffs</span><span class="p">,</span> <span class="s1">'db2'</span><span class="p">)</span> <span class="go">array([ 1., 2., 3., 4., 5., 6., 7., 8.])</span> </pre></div> </div> </dd></dl> </div> <div class="section" id="multilevel-2d-iswt2"> <h2>Multilevel 2D <code class="docutils literal notranslate"><span class="pre">iswt2</span></code><a class="headerlink" href="#multilevel-2d-iswt2" title="Permalink to this headline">¶</a></h2> <dl class="function"> <dt id="pywt.iswt2"> <code class="descclassname">pywt.</code><code class="descname">iswt2</code><span class="sig-paren">(</span><em>coeffs</em>, <em>wavelet</em><span class="sig-paren">)</span><a class="headerlink" href="#pywt.iswt2" title="Permalink to this definition">¶</a></dt> <dd><p>Multilevel 2D inverse discrete stationary wavelet transform.</p> <table class="docutils field-list" frame="void" rules="none"> <col class="field-name" /> <col class="field-body" /> <tbody valign="top"> <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><dl class="first docutils"> <dt><strong>coeffs</strong> <span class="classifier-delimiter">:</span> <span class="classifier">list</span></dt> <dd><p class="first">Approximation and details coefficients:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="p">[</span> <span class="p">(</span><span class="n">cA_n</span><span class="p">,</span> <span class="p">(</span><span class="n">cH_n</span><span class="p">,</span> <span class="n">cV_n</span><span class="p">,</span> <span class="n">cD_n</span><span class="p">)</span> <span class="p">),</span> <span class="o">...</span><span class="p">,</span> <span class="p">(</span><span class="n">cA_2</span><span class="p">,</span> <span class="p">(</span><span class="n">cH_2</span><span class="p">,</span> <span class="n">cV_2</span><span class="p">,</span> <span class="n">cD_2</span><span class="p">)</span> <span class="p">),</span> <span class="p">(</span><span class="n">cA_1</span><span class="p">,</span> <span class="p">(</span><span class="n">cH_1</span><span class="p">,</span> <span class="n">cV_1</span><span class="p">,</span> <span class="n">cD_1</span><span class="p">)</span> <span class="p">)</span> <span class="p">]</span> </pre></div> </div> <p class="last">where cA is approximation, cH is horizontal details, cV is vertical details, cD is diagonal details and n is the number of levels. Index 1 corresponds to <code class="docutils literal notranslate"><span class="pre">start_level</span></code> from <code class="docutils literal notranslate"><span class="pre">pywt.swt2</span></code>.</p> </dd> <dt><strong>wavelet</strong> <span class="classifier-delimiter">:</span> <span class="classifier">Wavelet object or name string, or 2-tuple of wavelets</span></dt> <dd><p class="first last">Wavelet to use. This can also be a 2-tuple of wavelets to apply per axis.</p> </dd> </dl> </td> </tr> <tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><dl class="first last docutils"> <dt><strong>2D array of reconstructed data.</strong></dt> <dd></dd> </dl> </td> </tr> </tbody> </table> <p class="rubric">Examples</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pywt</span> <span class="gp">>>> </span><span class="n">coeffs</span> <span class="o">=</span> <span class="n">pywt</span><span class="o">.</span><span class="n">swt2</span><span class="p">([[</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">3</span><span class="p">,</span><span class="mi">4</span><span class="p">],[</span><span class="mi">5</span><span class="p">,</span><span class="mi">6</span><span class="p">,</span><span class="mi">7</span><span class="p">,</span><span class="mi">8</span><span class="p">],</span> <span class="gp">... </span> <span class="p">[</span><span class="mi">9</span><span class="p">,</span><span class="mi">10</span><span class="p">,</span><span class="mi">11</span><span class="p">,</span><span class="mi">12</span><span class="p">],[</span><span class="mi">13</span><span class="p">,</span><span class="mi">14</span><span class="p">,</span><span class="mi">15</span><span class="p">,</span><span class="mi">16</span><span class="p">]],</span> <span class="gp">... </span> <span class="s1">'db1'</span><span class="p">,</span> <span class="n">level</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">pywt</span><span class="o">.</span><span class="n">iswt2</span><span class="p">(</span><span class="n">coeffs</span><span class="p">,</span> <span class="s1">'db1'</span><span class="p">)</span> <span class="go">array([[ 1., 2., 3., 4.],</span> <span class="go"> [ 5., 6., 7., 8.],</span> <span class="go"> [ 9., 10., 11., 12.],</span> <span class="go"> [ 13., 14., 15., 16.]])</span> </pre></div> </div> </dd></dl> </div> <div class="section" id="multilevel-n-dimensional-iswtn"> <h2>Multilevel n-dimensional <code class="docutils literal notranslate"><span class="pre">iswtn</span></code><a class="headerlink" href="#multilevel-n-dimensional-iswtn" title="Permalink to this headline">¶</a></h2> <dl class="function"> <dt id="pywt.iswtn"> <code class="descclassname">pywt.</code><code class="descname">iswtn</code><span class="sig-paren">(</span><em>coeffs</em>, <em>wavelet</em>, <em>axes=None</em><span class="sig-paren">)</span><a class="headerlink" href="#pywt.iswtn" title="Permalink to this definition">¶</a></dt> <dd><p>Multilevel nD inverse discrete stationary wavelet transform.</p> <table class="docutils field-list" frame="void" rules="none"> <col class="field-name" /> <col class="field-body" /> <tbody valign="top"> <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><dl class="first docutils"> <dt><strong>coeffs</strong> <span class="classifier-delimiter">:</span> <span class="classifier">list</span></dt> <dd><p class="first last">[{coeffs_level_n}, …, {coeffs_level_1}]: list of dict</p> </dd> <dt><strong>wavelet</strong> <span class="classifier-delimiter">:</span> <span class="classifier">Wavelet object or name string, or tuple of wavelets</span></dt> <dd><p class="first last">Wavelet to use. This can also be a tuple of wavelets to apply per axis in <code class="docutils literal notranslate"><span class="pre">axes</span></code>.</p> </dd> <dt><strong>axes</strong> <span class="classifier-delimiter">:</span> <span class="classifier">sequence of ints, optional</span></dt> <dd><p class="first last">Axes over which to compute the inverse SWT. Axes may not be repeated. The default is <code class="docutils literal notranslate"><span class="pre">None</span></code>, which means transform all axes (<code class="docutils literal notranslate"><span class="pre">axes</span> <span class="pre">=</span> <span class="pre">range(data.ndim)</span></code>).</p> </dd> </dl> </td> </tr> <tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><dl class="first last docutils"> <dt><strong>nD array of reconstructed data.</strong></dt> <dd></dd> </dl> </td> </tr> </tbody> </table> <p class="rubric">Examples</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pywt</span> <span class="gp">>>> </span><span class="n">coeffs</span> <span class="o">=</span> <span class="n">pywt</span><span class="o">.</span><span class="n">swtn</span><span class="p">([[</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">3</span><span class="p">,</span><span class="mi">4</span><span class="p">],[</span><span class="mi">5</span><span class="p">,</span><span class="mi">6</span><span class="p">,</span><span class="mi">7</span><span class="p">,</span><span class="mi">8</span><span class="p">],</span> <span class="gp">... </span> <span class="p">[</span><span class="mi">9</span><span class="p">,</span><span class="mi">10</span><span class="p">,</span><span class="mi">11</span><span class="p">,</span><span class="mi">12</span><span class="p">],[</span><span class="mi">13</span><span class="p">,</span><span class="mi">14</span><span class="p">,</span><span class="mi">15</span><span class="p">,</span><span class="mi">16</span><span class="p">]],</span> <span class="gp">... </span> <span class="s1">'db1'</span><span class="p">,</span> <span class="n">level</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span> <span class="gp">>>> </span><span class="n">pywt</span><span class="o">.</span><span class="n">iswtn</span><span class="p">(</span><span class="n">coeffs</span><span class="p">,</span> <span class="s1">'db1'</span><span class="p">)</span> <span class="go">array([[ 1., 2., 3., 4.],</span> <span class="go"> [ 5., 6., 7., 8.],</span> <span class="go"> [ 9., 10., 11., 12.],</span> <span class="go"> [ 13., 14., 15., 16.]])</span> </pre></div> </div> </dd></dl> </div> </div> </div> </div> </div> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h3><a href="../index.html">Table of Contents</a></h3> <ul> <li><a class="reference internal" href="#">Inverse Stationary Wavelet Transform</a><ul> <li><a class="reference internal" href="#multilevel-1d-iswt">Multilevel 1D <code class="docutils literal notranslate"><span class="pre">iswt</span></code></a></li> <li><a class="reference internal" href="#multilevel-2d-iswt2">Multilevel 2D <code class="docutils literal notranslate"><span class="pre">iswt2</span></code></a></li> <li><a class="reference internal" href="#multilevel-n-dimensional-iswtn">Multilevel n-dimensional <code class="docutils literal notranslate"><span class="pre">iswtn</span></code></a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="swt-stationary-wavelet-transform.html" title="previous chapter">Stationary Wavelet Transform</a></p> <h4>Next topic</h4> <p class="topless"><a href="wavelet-packets.html" title="next chapter">Wavelet Packets</a></p><div> <h3>Quick links</h3> <ul> <li><a href="https://github.com/PyWavelets/pywt"><img src="../_static/github.png" height="16" width="16" alt="" /> Fork on Github</a></li> <li><a href="http://groups.google.com/group/pywavelets"><img src="../_static/comments.png" height="16" width="16" alt="" /> Discussion Group</a></li> <li><a href="http://wavelets.pybytes.com/"><img src="../_static/wave.png" height="16" width="16" alt="" /> Explore Wavelets</a></li> </ul> </div> <div id="searchbox" style="display: none" role="search"> <h3>Quick search</h3> <div class="searchformwrapper"> <form class="search" action="../search.html" method="get"> <input type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </div> </div> <script type="text/javascript">$('#searchbox').show(0);</script> <div id="edit-instructions"> <h3>Edit this document</h3> <p> <a href="#" id="toggle-edit-info"> <img src="../_static/page_edit.png" height="16" width="16" alt="" /> The source code of this file is hosted on GitHub. 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