To convert foaf img:depiction data to an SVG you:

<svg width="100%" height="100%">
<image clip-path="url(#ref0)" opacity="1" width="put the http://jibbering.com/2002/3/#width literal here"
 height="put the http://jibbering.com/2002/3/#height literal here"
 x="0" y="0" xmlns:xlink="http://www.w3.org/1999/xlink"  
     xlink:href="put the uri of the photo here"> </image>
 <g clip-rule="evenodd" >  <clipPath id="ref0">
 <path id="pathref0" d="put the http://jibbering.com/2002/3/#polypath literal here" fill="red" />
</clipPath>
</g>
</svg>