Floodfill rasterized skeleton (and not skeleton directly FIXME).
Fix floodfill (Visit first 6 face neighbours and not 8 corners ><...).
Fixes.
Naive median filter (using selection sort).
Two level histogram median.
Cleanups, correct fast median (using 4 histogram levels).
Correct median histogram window sliding.
Prune after rasterization.
Generalized sweep expressions.