<s>
In	O
image	B-Algorithm
processing	I-Algorithm
,	O
elongatedness	B-Algorithm
for	O
a	O
region	O
is	O
the	O
ratio	O
between	O
the	O
length	O
and	O
width	O
of	O
the	O
minimum	B-Algorithm
bounding	I-Algorithm
rectangle	I-Algorithm
of	O
the	O
region	O
.	O
</s>
<s>
It	O
is	O
considered	O
a	O
feature	B-Algorithm
of	O
the	O
region	O
.	O
</s>
<s>
where	O
the	O
maximum	O
thickness	O
,	O
,	O
of	O
a	O
holeless	O
region	O
is	O
given	O
by	O
the	O
number	O
of	O
times	O
the	O
region	O
can	O
be	O
eroded	B-Algorithm
before	O
disappearing	O
.	O
</s>
