@phcerdan Thanks for your reply! I just pushed a new version of NeighborhoodRange onto Gerrit, with added support for arbitrarily shaped neighborhoods: Patch Set 8, http://review.source.kitware.com/#/c/23326/8
Is it possible for you to try out the patch? If so, can you please do the same performance test again, from Removal of `virtual` keywords from ConstNeighborhoodIterator ?