<s>
In	O
image	B-Algorithm
processing	I-Algorithm
,	O
the	O
free	B-Algorithm
boundary	I-Algorithm
condition	I-Algorithm
is	O
the	O
convention	O
used	O
when	O
applying	O
a	O
convolution	O
kernel	O
to	O
a	O
digital	B-Algorithm
image	I-Algorithm
in	O
which	O
pixel	O
locations	O
that	O
lie	O
outside	O
the	O
image	O
boundaries	O
are	O
interpreted	O
as	O
having	O
a	O
value	O
of	O
zero	O
.	O
</s>
