SVG version of public domain image Bilinear_interpolation.fig from en.wikipedia.org
<a href="//commons.wikimedia.org/w/index.php?title=User:Bocsika&amp;action=edit&amp;redlink=1" class="new" title="User:Bocsika (page does not exist)">Bocsika</a>
<span class="int-own-work" lang="en">Own work</span>