This SVG example illustrates how to apply a morphology filter.

MorphologyFilter.svg

<svg width="400" height="200" xmlns="http://www.w3.org/2000/svg">
  <filter id="idMorphologyFilter">
    <feMorphology operator="erode" radius="15"/>
  </filter>
  <!-- Original Version -->
  <circle cx="100" cy="100" r="85" fill="blue" stroke="none" stroke-width="10"></circle>
  <!-- Filtered Version -->
  <g style="filter: url(#idMorphologyFilter)" transform="translate(200, 0)">
    <circle cx="100" cy="100" r="85" fill="blue" stroke="none" stroke-width="10"></circle>
  </g>
</svg>

Output