<s>
In	O
signal	O
processing	O
,	O
the	O
adjoint	B-Algorithm
filter	I-Algorithm
mask	O
of	O
a	O
filter	O
mask	O
is	O
reversed	O
in	O
time	O
and	O
the	O
elements	O
are	O
complex	O
conjugated	O
.	O
</s>
<s>
Its	O
name	O
is	O
derived	O
from	O
the	O
fact	O
that	O
the	O
convolution	O
with	O
the	O
adjoint	B-Algorithm
filter	I-Algorithm
is	O
the	O
adjoint	O
operator	O
of	O
the	O
original	O
filter	O
,	O
with	O
respect	O
to	O
the	O
Hilbert	O
space	O
of	O
the	O
sequences	O
in	O
which	O
the	O
inner	O
product	O
is	O
the	O
Euclidean	O
norm	O
.	O
</s>
