Of course since the kernel is no longer separable, it becomes awfully
slow with large images. Here is a tileable brushed metal texture:
# pipi pipi:random512x512 --wrap --blur 20x0r25 -o image.png
git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@2715 92316355-f0b4-4df1-b90c-862c8a59935f
about twice as fast as the original code in research/2008-displacement.
git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@2644 92316355-f0b4-4df1-b90c-862c8a59935f
sam