   <li><a class="dropdown-item" href="../articles/manipulation.html">Image manipulation</a></li>
    <li><a class="dropdown-item" href="../articles/indexes.html">Image indexes</a></li>
    <li><a class="dropdown-item" href="../articles/segmentation.html">Image segmentation</a></li>
    <li><a class="dropdown-item" href="../articles/polygons.html">Polygons</a></li>
    <li><a class="dropdown-item" href="../articles/analyze_objects.html">Image analysis</a></li>
    <li><a class="dropdown-item" href="../articl