 the <a href="overlay/contours/../overlay_graph/overlay_graph.html">Overlay Graph</a>, contours are used to represent the boundaries of geometric objects. These contours are classified into two types: <span style="color:#ff3333ff;"><strong>outer</strong></span> contours and <span style="color:#1a8effff;"><strong>inner</strong></span> contours.</p>
<h3 id="outer-contour"><a class="header" href="#outer-contour">Outer Contour:</a></h3>
<ul>
<li>An outer contour is a sequence of points ordered in a <strong>coun