2014-10-22 UTC
# 
tantek in OctalGeo, each part of each digit "means" the same thing in terms of directions (NS/EW). whereas in a hilbert curve compression, each "digit" rotates its meaning depending on the value of the previous digit. this is illustrated by this diagram: http://upload.wikimedia.org/wikipedia/commons/5/5f/Figure2_Hilbert.gif