This figure illustrates the closing.
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from morph import *
from Numeric import indices
from MLab import fliplr
B=mmsedisk(10)
mmshow(mmseshow(B))
y,x=indices((70,50))
F= mmbinary((2*x) < (y))
F=mmunion(F,fliplr(F))
F=mmpad(F,mmsedisk(11))
mmshow(F)
E=mmdil(F,B)
mmshow(E)
O=mmclose(F,B)
mmshow(O)