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<h2 id="define-shape"><a class="header" href="#define-shape">Define Shape</a></h2>
<p><img src="overlay/extract/define_shape.svg" alt="Define Shape" /></p>
<p>A shape is defined as a group of contours, where the first contour is always an <span style="color:#ff3333ff;"><strong>outer</strong></span> contour, and the subsequent contours (if any) are <span style="color:#1a8effff;"><strong>inner</strong></span> contours.</p>
<h2 id="matching-contours"><a class="header" href="#matching-contours">Matching Conto