<s>
A	O
Robinson	B-Algorithm
compass	I-Algorithm
mask	I-Algorithm
is	O
a	O
type	O
of	O
compass	O
mask	O
used	O
for	O
edge	B-Algorithm
detection	I-Algorithm
.	O
</s>
<s>
The	O
Robinson	B-Algorithm
compass	I-Algorithm
mask	I-Algorithm
is	O
defined	O
by	O
taking	O
a	O
single	O
mask	O
and	O
rotating	O
it	O
to	O
form	O
eight	O
orientations	O
:	O
</s>
<s>
Robinson	B-Algorithm
compass	I-Algorithm
mask	I-Algorithm
is	O
similar	O
to	O
kirsch	O
compass	O
masks	O
,	O
but	O
is	O
simpler	O
to	O
implement	O
.	O
</s>
<s>
An	O
example	O
of	O
Robinson	B-Algorithm
compass	I-Algorithm
masks	I-Algorithm
applied	O
to	O
the	O
original	O
image	O
.	O
</s>
