This figure illustrates the equivalence between the distance transform and erosions by disks.
.
from morph import *
f=mmreadgray('blob.tif')
f1=mmero(f,mmsedisk(6))
f2=mmero(f,mmsedisk(12))
f3=mmero(f,mmsedisk(18))
mmshow(f)
mmshow(f1)
mmshow(f2)
mmshow(f3)
