<s>
Elias	O
code	O
or	O
Elias	B-Algorithm
gamma	I-Algorithm
code	I-Algorithm
is	O
a	O
universal	B-Algorithm
code	I-Algorithm
encoding	O
positive	O
integers	O
developed	O
by	O
Peter	O
Elias	O
.	O
</s>
<s>
To	O
represent	O
a	O
number	O
,	O
Elias	B-Algorithm
gamma	I-Algorithm
( γ	O
)	O
uses	O
bits	O
.	O
</s>
<s>
Gamma	B-Algorithm
coding	I-Algorithm
is	O
used	O
in	O
applications	O
where	O
the	O
largest	O
encoded	O
value	O
is	O
not	O
known	O
ahead	O
of	O
time	O
,	O
or	O
to	O
compress	B-General_Concept
data	O
in	O
which	O
small	O
values	O
are	O
much	O
more	O
frequent	O
than	O
large	O
values	O
.	O
</s>
<s>
Gamma	B-Algorithm
coding	I-Algorithm
is	O
a	O
building	O
block	O
in	O
the	O
Elias	B-Algorithm
delta	I-Algorithm
code	I-Algorithm
.	O
</s>
<s>
Gamma	B-Algorithm
coding	I-Algorithm
does	O
not	O
code	O
zero	O
or	O
negative	O
integers	O
.	O
</s>
<s>
One	O
way	O
to	O
code	O
all	O
integers	O
is	O
to	O
set	O
up	O
a	O
bijection	B-Algorithm
,	O
mapping	O
integers	O
(	O
0	O
,	O
−1	O
,	O
1	O
,	O
−2	O
,	O
2	O
,	O
−3	O
,	O
3	O
,	O
...	O
)	O
to	O
(	O
1	O
,	O
2	O
,	O
3	O
,	O
4	O
,	O
5	O
,	O
6	O
,	O
7	O
,	O
...	O
)	O
before	O
coding	O
.	O
</s>
<s>
In	O
software	O
,	O
this	O
is	O
most	O
easily	O
done	O
by	O
mapping	O
non-negative	O
inputs	O
to	O
odd	O
outputs	O
,	O
and	O
negative	O
inputs	O
to	O
even	O
outputs	O
,	O
so	O
the	O
least-significant	O
bit	O
becomes	O
an	O
inverted	O
sign	B-Algorithm
bit	I-Algorithm
:	O
</s>
<s>
Exponential-Golomb	B-Algorithm
coding	I-Algorithm
generalizes	O
the	O
gamma	B-Algorithm
code	I-Algorithm
to	O
integers	O
with	O
a	O
"	O
flatter	O
"	O
power-law	O
distribution	O
,	O
just	O
as	O
Golomb	B-Algorithm
coding	I-Algorithm
generalizes	O
the	O
unary	O
code	O
.	O
</s>
<s>
It	O
involves	O
dividing	O
the	O
number	O
by	O
a	O
positive	O
divisor	O
,	O
commonly	O
a	O
power	O
of	O
2	O
,	O
writing	O
the	O
gamma	B-Algorithm
code	I-Algorithm
for	O
one	O
more	O
than	O
the	O
quotient	O
,	O
and	O
writing	O
out	O
the	O
remainder	O
in	O
an	O
ordinary	O
binary	O
code	O
.	O
</s>
