<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> <meta http-equiv="X-UA-Compatible" content="IE=9"/> <meta name="generator" content="Doxygen 1.9.1"/> <meta name="viewport" content="width=device-width, initial-scale=1"/> <title>DGtal: Tutorial "File -> Grid Curve -> Ranges"</title> <link href="tabs.css" rel="stylesheet" type="text/css"/> <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript" src="dynsections.js"></script> <link href="navtree.css" rel="stylesheet" type="text/css"/> <script type="text/javascript" src="resize.js"></script> <script type="text/javascript" src="navtreedata.js"></script> <script type="text/javascript" src="navtree.js"></script> <link href="search/search.css" rel="stylesheet" type="text/css"/> <script type="text/javascript" src="search/searchdata.js"></script> <script type="text/javascript" src="search/search.js"></script> <script type="text/x-mathjax-config"> MathJax.Hub.Config({ extensions: ["tex2jax.js", "TeX/AMSmath.js", "TeX/AMSsymbols.js"], jax: ["input/TeX","output/HTML-CSS"], }); 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$(document).ready(function() { init_search(); }); }); /* @license-end */</script> <div id="main-nav"></div> </div><!-- top --> <div id="side-nav" class="ui-resizable side-nav-resizable"> <div id="nav-tree"> <div id="nav-tree-contents"> <div id="nav-sync" class="sync"></div> </div> </div> <div id="splitbar" style="-moz-user-select:none;" class="ui-resizable-handle"> </div> </div> <script type="text/javascript"> /* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt GPL-v2 */ $(document).ready(function(){initNavTree('tutoFileGridCurveRanges.html',''); initResizable(); }); /* @license-end */ </script> <div id="doc-content"> <!-- window showing the filter options --> <div id="MSearchSelectWindow" onmouseover="return searchBox.OnSearchSelectShow()" onmouseout="return searchBox.OnSearchSelectHide()" onkeydown="return searchBox.OnSearchSelectKey(event)"> </div> <!-- iframe showing the search results (closed by default) --> <div id="MSearchResultsWindow"> <iframe src="javascript:void(0)" frameborder="0" name="MSearchResults" id="MSearchResults"> </iframe> </div> <div class="PageDoc"><div class="header"> <div class="headertitle"> <div class="title">Tutorial "File -> Grid Curve -> Ranges" </div> </div> </div><!--header--> <div class="contents"> <div class="toc"><h3>Table of Contents</h3> <ul><li class="level1"><a href="#secttutofileGridCurveRanges0">Declaration</a></li> <li class="level1"><a href="#secttutofileGridCurveRanges1">Reading a grid curve from a file</a></li> <li class="level1"><a href="#secttutofileGridCurveRanges2">Displaying a grid curve with Board2D</a></li> <li class="level1"><a href="#secttutofileGridCurveRanges3">Ranges</a></li> <li class="level1"><a href="#secttutofileGridCurveRanges4">Required includes</a></li> </ul> </div> <div class="textblock"><dl class="section user"><dt>Author(s) of this documentation: </dt><dd>Tristan Roussillon</dd></dl> <h1><a class="anchor" id="secttutofileGridCurveRanges0"></a> Declaration</h1> <p>In this example, we show how to use the <a class="el" href="classDGtal_1_1GridCurve.html" title="Aim: describes, in a cellular space of dimension n, a closed or open sequence of signed d-cells (or d...">GridCurve</a> object, which is key to analyze digital curves. <br /> </p> <p>Using the <a class="el" href="namespaceDGtal_1_1Z2i.html" title="Z2i this namespace gathers the standard of types for 2D imagery.">Z2i</a> shortcut, you can merely declare it as follows:</p> <div class="fragment"><div class="line"> <a class="code" href="namespaceDGtal_1_1Z2i.html#a503faf4d34b6500e8f14035911fa04d5">Z2i::Curve</a> c; </div> <div class="ttc" id="anamespaceDGtal_1_1Z2i_html_a503faf4d34b6500e8f14035911fa04d5"><div class="ttname"><a href="namespaceDGtal_1_1Z2i.html#a503faf4d34b6500e8f14035911fa04d5">DGtal::Z2i::Curve</a></div><div class="ttdeci">GridCurve< K2 > Curve</div><div class="ttdef"><b>Definition:</b> <a href="StdDefs_8h_source.html#l00116">StdDefs.h:116</a></div></div> </div><!-- fragment --> <dl class="section note"><dt>Note</dt><dd>The <a class="el" href="classDGtal_1_1GridCurve.html" title="Aim: describes, in a cellular space of dimension n, a closed or open sequence of signed d-cells (or d...">GridCurve</a> object stands for an open or closed oriented grid curve, i.e. an alternating sequence of signed 0- and 1-cells.</dd></dl> <h1><a class="anchor" id="secttutofileGridCurveRanges1"></a> Reading a grid curve from a file</h1> <p>You can load your grid curve from a text file that contains the coordinates of some points (each coordinate separated by a white space and one point per line).</p> <div class="fragment"><div class="line"> std::string <a class="code" href="namespaceDGtal_1_1functions.html#ac8e2160844093488cdd738354027daa1">square</a> = examplesPath + <span class="stringliteral">"samples/smallSquare.dat"</span>; </div> <div class="ttc" id="anamespaceDGtal_1_1functions_html_ac8e2160844093488cdd738354027daa1"><div class="ttname"><a href="namespaceDGtal_1_1functions.html#ac8e2160844093488cdd738354027daa1">DGtal::functions::square</a></div><div class="ttdeci">T square(T x)</div><div class="ttdef"><b>Definition:</b> <a href="BasicMathFunctions_8h_source.html#l00133">BasicMathFunctions.h:133</a></div></div> </div><!-- fragment --><p> For instance, the file smallSquare.dat used above contains: </p><div class="fragment"><div class="line">0 0</div> <div class="line">0 1</div> <div class="line">0 2</div> <div class="line">0 3</div> <div class="line">1 3</div> <div class="line">...</div> </div><!-- fragment --><p>Using the STL file stream, you can initialize your grid curve from the file data as follows:</p> <div class="fragment"><div class="line"> std::fstream inputStream;</div> <div class="line"> inputStream.open (<a class="code" href="namespaceDGtal_1_1functions.html#ac8e2160844093488cdd738354027daa1">square</a>.c_str(), std::ios::in);</div> <div class="line"> c.initFromVectorStream(inputStream);</div> <div class="line"> inputStream.close(); </div> </div><!-- fragment --> <dl class="section note"><dt>Note</dt><dd>The coordinates of each point are assumed to be the digital coordinates of the 0-cells. These points are thus assumed to be 4-connected. The grid curve is assumed to be closed iff the first and last point are equal or 4-connected.</dd> <dd> A <a class="el" href="classDGtal_1_1IOException.html">DGtal::IOException</a> is raised in the case of IO errors and a <a class="el" href="classDGtal_1_1ConnectivityException.html">DGtal::ConnectivityException</a> is raised if the points are not 4-connected.</dd></dl> <h1><a class="anchor" id="secttutofileGridCurveRanges2"></a> Displaying a grid curve with Board2D</h1> <p><a class="el" href="classDGtal_1_1Board2D.html" title="Aim: This class specializes a 'Board' class so as to display DGtal objects more naturally (with <<)....">DGtal::Board2D</a> is a nice way of displaying many 2D objects. <br /> See <a class="el" href="moduleBoard2D.html">Board2D: a stream mechanism for displaying 2D digital objects</a> for further details.</p> <div class="fragment"><div class="line"> <a class="code" href="classDGtal_1_1Board2D.html">DGtal::Board2D</a> aBoard;</div> <div class="ttc" id="aclassDGtal_1_1Board2D_html"><div class="ttname"><a href="classDGtal_1_1Board2D.html">DGtal::Board2D</a></div><div class="ttdoc">Aim: This class specializes a 'Board' class so as to display DGtal objects more naturally (with <<)....</div><div class="ttdef"><b>Definition:</b> <a href="Board2D_8h_source.html#l00070">Board2D.h:71</a></div></div> </div><!-- fragment --><p> Using the stream mechanism of <a class="el" href="classDGtal_1_1Board2D.html" title="Aim: This class specializes a 'Board' class so as to display DGtal objects more naturally (with <<)....">DGtal::Board2D</a>, you can write your grid curve in a vector-graphics file (here in postscript, but xfig, svg, pdf are other available formats).</p> <div class="fragment"><div class="line"> aBoard << c; </div> <div class="line"> aBoard.<a class="code" href="classLibBoard_1_1Board.html#ac39d5033a3a95e50f8ab7772e24c56bb">saveEPS</a>(<span class="stringliteral">"DisplayGridCurveTuto.eps"</span>);</div> <div class="ttc" id="aclassLibBoard_1_1Board_html_ac39d5033a3a95e50f8ab7772e24c56bb"><div class="ttname"><a href="classLibBoard_1_1Board.html#ac39d5033a3a95e50f8ab7772e24c56bb">LibBoard::Board::saveEPS</a></div><div class="ttdeci">void saveEPS(const char *filename, PageSize size=Board::BoundingBox, double margin=10.0) const</div><div class="ttdef"><b>Definition:</b> <a href="Board_8cpp_source.html#l00804">Board.cpp:804</a></div></div> </div><!-- fragment --><p> Here is a png conversion of the resulting image:</p> <div class="image"> <img src="DisplayGridCurveTuto.png" alt=""/> <div class="caption"> A small closed grid curve</div></div> <h1><a class="anchor" id="secttutofileGridCurveRanges3"></a> Ranges</h1> <p>A same digital curve may be viewed in very different ways: <br /> either as an alternating sequence of cells, or as a sequence of points, or as a sequence of codes, and so one. <br /> Moreover, some processing algorithms require a specific type of elements: either 4-connected points, 8-connected points, grid edges, and so one. <br /> That is why the <a class="el" href="classDGtal_1_1GridCurve.html" title="Aim: describes, in a cellular space of dimension n, a closed or open sequence of signed d-cells (or d...">GridCurve</a> object provides many ranges, i.e. <br /> objects that provides services to iterate over a sequence of elements. <br /> </p> <p>For instance, if you have to (or want to) work with 8-connected digital curves, you can get the grid curve inner points as follows: <br /> </p> <div class="fragment"><div class="line"> <a class="code" href="classDGtal_1_1GridCurve.html#a87afc16bfc83d8ac12bf20e8d864b038">Z2i::Curve::InnerPointsRange</a> r1 = c.getInnerPointsRange(); </div> <div class="line"> aBoard << r1; </div> <div class="ttc" id="aclassDGtal_1_1GridCurve_html_a87afc16bfc83d8ac12bf20e8d864b038"><div class="ttname"><a href="classDGtal_1_1GridCurve.html#a87afc16bfc83d8ac12bf20e8d864b038">DGtal::GridCurve::InnerPointsRange</a></div><div class="ttdeci">ConstRangeAdapter< typename Storage::const_iterator, functors::SCellToInnerPoint< KSpace >, Point > InnerPointsRange</div><div class="ttdef"><b>Definition:</b> <a href="GridCurve_8h_source.html#l00457">GridCurve.h:457</a></div></div> </div><!-- fragment --> <div class="image"> <img src="DisplayInnerPointsTuto.png" alt=""/> <div class="caption"> Inner points</div></div> <p>If you have to (or want to) work with separating algorithms, you can get the grid curve incident points as follows:</p> <div class="fragment"><div class="line"> <a class="code" href="classDGtal_1_1GridCurve.html#a9c658d0cc9f74f944149e985341f74ea">Z2i::Curve::IncidentPointsRange</a> r2 = c.getIncidentPointsRange(); </div> <div class="line"> aBoard << r2; </div> <div class="ttc" id="aclassDGtal_1_1GridCurve_html_a9c658d0cc9f74f944149e985341f74ea"><div class="ttname"><a href="classDGtal_1_1GridCurve.html#a9c658d0cc9f74f944149e985341f74ea">DGtal::GridCurve::IncidentPointsRange</a></div><div class="ttdeci">ConstRangeAdapter< typename Storage::const_iterator, functors::SCellToIncidentPoints< KSpace >, std::pair< Point, Point > > IncidentPointsRange</div><div class="ttdef"><b>Definition:</b> <a href="GridCurve_8h_source.html#l00481">GridCurve.h:481</a></div></div> </div><!-- fragment --> <div class="image"> <img src="DisplayIncidentPointsTuto.png" alt=""/> <div class="caption"> Incident points</div></div> <p>See <a class="el" href="classDGtal_1_1GridCurve.html" title="Aim: describes, in a cellular space of dimension n, a closed or open sequence of signed d-cells (or d...">GridCurve</a> for the exhaustive list of available ranges and their basic usage. See <a class="el" href="moduleGridCurveAnalysis.html">Analysis of one-dimensional discrete structures</a> for a general introduction about digital curves analysis.</p> <h1><a class="anchor" id="secttutofileGridCurveRanges4"></a> Required includes</h1> <p>Here are the basic includes:</p> <div class="fragment"><div class="line"><span class="preprocessor">#include "DGtal/base/Common.h"</span></div> <div class="line"><span class="preprocessor">#include "DGtal/helpers/StdDefs.h"</span></div> <div class="line"><span class="preprocessor">#include "ConfigExamples.h"</span></div> </div><!-- fragment --> <dl class="section note"><dt>Note</dt><dd><a class="el" href="StdDefs_8h_source.html">StdDefs.h</a> contains the <a class="el" href="namespaceDGtal_1_1Z2i.html" title="Z2i this namespace gathers the standard of types for 2D imagery.">Z2i</a> namespace, which provides many type shortcuts. It includes the header required for the <a class="el" href="classDGtal_1_1GridCurve.html" title="Aim: describes, in a cellular space of dimension n, a closed or open sequence of signed d-cells (or d...">GridCurve</a> object. ConfigExamples.h only provides the files sample path.</dd></dl> <p>In order to use the drawing mechanism, you have to include:</p> <div class="fragment"><div class="line"><span class="preprocessor">#include "DGtal/io/boards/Board2D.h"</span></div> </div><!-- fragment --></div></div><!-- contents --> </div><!-- PageDoc --> </div><!-- doc-content --> <!-- start footer part --> <div id="nav-path" class="navpath"><!-- id is needed for treeview function! --> <ul> <li class="navelem"><a class="el" href="index.html">DGtal - Digital Geometry Tools and Algorithms Library.</a></li><li class="navelem"><a class="el" href="packageTutorials.html">Tutorials</a></li> <li class="footer">Generated on Mon Dec 23 2024 13:18:57 for DGtal by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.1 </li> </ul> </div> </body> </html>