<s>
Adaptive	B-Algorithm
coding	I-Algorithm
refers	O
to	O
variants	O
of	O
entropy	B-Algorithm
encoding	I-Algorithm
methods	O
of	O
lossless	B-Algorithm
data	I-Algorithm
compression	I-Algorithm
.	O
</s>
<s>
They	O
are	O
particularly	O
suited	O
to	O
streaming	B-Operating_System
data	I-Operating_System
,	O
as	O
they	O
adapt	O
to	O
localized	O
changes	O
in	O
the	O
characteristics	O
of	O
the	O
data	O
,	O
and	O
do	O
n't	O
require	O
a	O
first	O
pass	O
over	O
the	O
data	O
to	O
calculate	O
a	O
probability	O
model	O
.	O
</s>
<s>
Almost	O
all	O
data	B-General_Concept
compression	I-General_Concept
methods	O
involve	O
the	O
use	O
of	O
a	O
model	O
,	O
a	O
prediction	O
of	O
the	O
composition	O
of	O
the	O
data	O
.	O
</s>
<s>
This	O
general	O
statement	O
is	O
a	O
bit	O
misleading	O
as	O
general	O
data	B-General_Concept
compression	I-General_Concept
algorithms	I-General_Concept
would	O
include	O
the	O
popular	O
LZW	B-Algorithm
and	O
LZ77	O
algorithms	O
,	O
</s>
<s>
which	O
are	O
hardly	O
comparable	O
to	O
compression	B-General_Concept
techniques	I-General_Concept
typically	O
called	O
adaptive	O
.	O
</s>
<s>
Run-length	B-Algorithm
encoding	I-Algorithm
and	O
the	O
typical	O
JPEG	O
compression	O
with	O
run	B-Algorithm
length	I-Algorithm
encoding	I-Algorithm
and	O
predefined	O
Huffman	O
codes	O
do	O
not	O
transmit	O
a	O
model	O
.	O
</s>
<s>
In	O
adaptive	B-Algorithm
coding	I-Algorithm
,	O
the	O
encoder	O
and	O
decoder	O
are	O
instead	O
equipped	O
with	O
a	O
predefined	O
meta-model	O
about	O
how	O
they	O
will	O
alter	O
their	O
models	O
in	O
response	O
to	O
the	O
actual	O
content	O
of	O
the	O
data	O
,	O
and	O
otherwise	O
start	O
with	O
a	O
blank	O
slate	O
,	O
meaning	O
that	O
no	O
initial	O
model	O
needs	O
to	O
be	O
transmitted	O
.	O
</s>
<s>
Any	O
adaptive	B-Algorithm
coding	I-Algorithm
method	O
has	O
a	O
corresponding	O
static	O
model	O
method	O
,	O
in	O
which	O
the	O
data	O
model	O
is	O
precalculated	O
and	O
then	O
transmitted	O
with	O
the	O
data	O
.	O
</s>
<s>
Adaptive	O
image	O
coding	O
was	O
used	O
by	O
the	O
Cassini-Huygens	O
craft	O
to	O
relay	O
images	O
from	O
Saturn	B-Device
.	O
</s>
<s>
As	O
the	O
spacecraft	O
has	O
an	O
error	O
correcting	O
Flash	B-Device
drive	I-Device
and	O
long	O
timeframes	O
between	O
image	O
taking	O
events	O
,	O
damaged	O
images	O
like	O
this	O
can	O
be	O
present	O
.	O
</s>
<s>
Both	O
converted	O
(	O
8-bit	O
)	O
and	O
unconverted	O
(	O
12-bit	O
)	O
data	O
can	O
be	O
losslessly	B-Algorithm
compressed	O
.	O
</s>
