<s>
An	O
image	B-Algorithm
processor	I-Algorithm
,	O
also	O
known	O
as	O
an	O
image	B-General_Concept
processing	I-General_Concept
engine	I-General_Concept
,	O
image	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
(	O
IPU	O
)	O
,	O
or	O
image	B-General_Concept
signal	I-General_Concept
processor	I-General_Concept
(	O
ISP	O
)	O
,	O
is	O
a	O
type	O
of	O
media	B-General_Concept
processor	I-General_Concept
or	O
specialized	O
digital	B-Architecture
signal	I-Architecture
processor	I-Architecture
(	O
DSP	O
)	O
used	O
for	O
image	B-Algorithm
processing	I-Algorithm
,	O
in	O
digital	B-Device
cameras	I-Device
or	O
other	O
devices	O
.	O
</s>
<s>
Image	B-General_Concept
processors	I-General_Concept
often	O
employ	O
parallel	B-Operating_System
computing	I-Operating_System
even	O
with	O
SIMD	B-Device
or	O
MIMD	B-Operating_System
technologies	O
to	O
increase	O
speed	O
and	O
efficiency	O
.	O
</s>
<s>
The	O
digital	B-Algorithm
image	I-Algorithm
processing	I-Algorithm
engine	O
can	O
perform	O
a	O
range	O
of	O
tasks	O
.	O
</s>
<s>
To	O
increase	O
the	O
system	O
integration	O
on	O
embedded	O
devices	O
,	O
often	O
it	O
is	O
a	O
system	B-Architecture
on	I-Architecture
a	I-Architecture
chip	I-Architecture
with	O
multi-core	B-Architecture
processor	I-Architecture
architecture	O
.	O
</s>
<s>
The	O
photodiodes	O
employed	O
in	O
an	O
image	B-Algorithm
sensor	I-Algorithm
are	O
color-blind	O
by	O
nature	O
:	O
they	O
can	O
only	O
record	O
shades	O
of	O
grey	O
.	O
</s>
<s>
To	O
get	O
color	O
into	O
the	O
picture	O
,	O
they	O
are	O
covered	O
with	O
different	O
color	O
filters	O
:	O
red	O
,	O
green	O
and	O
blue	O
(	O
RGB	O
)	O
according	O
to	O
the	O
pattern	O
designated	O
by	O
the	O
Bayer	B-Algorithm
filter	I-Algorithm
-	O
named	O
after	O
its	O
inventor	O
.	O
</s>
<s>
As	O
each	O
photodiode	O
records	O
the	O
color	O
information	O
for	O
exactly	O
one	O
pixel	B-Algorithm
of	O
the	O
image	O
,	O
without	O
an	O
image	B-Algorithm
processor	I-Algorithm
there	O
would	O
be	O
a	O
green	O
pixel	B-Algorithm
next	O
to	O
each	O
red	O
and	O
blue	O
pixel	B-Algorithm
.	O
</s>
<s>
As	O
stated	O
above	O
,	O
the	O
image	B-Algorithm
processor	I-Algorithm
evaluates	O
the	O
color	O
and	O
brightness	O
data	O
of	O
a	O
given	O
pixel	B-Algorithm
,	O
compares	O
them	O
with	O
the	O
data	O
from	O
neighboring	O
pixels	B-Algorithm
and	O
then	O
uses	O
a	O
demosaicing	B-Algorithm
algorithm	O
to	O
produce	O
an	O
appropriate	O
colour	O
and	O
brightness	O
value	O
for	O
the	O
pixel	B-Algorithm
.	O
</s>
<s>
The	O
image	B-Algorithm
processor	I-Algorithm
also	O
assesses	O
the	O
whole	O
picture	O
to	O
guess	O
at	O
the	O
correct	O
distribution	O
of	O
contrast	O
.	O
</s>
<s>
Noise	B-Algorithm
is	O
a	O
phenomenon	O
found	O
in	O
any	O
electronic	O
circuitry	O
.	O
</s>
<s>
Noise	B-Algorithm
increases	O
with	O
temperature	O
and	O
exposure	O
times	O
.	O
</s>
<s>
When	O
higher	O
ISO	O
settings	O
are	O
chosen	O
the	O
electronic	O
signal	O
in	O
the	O
image	B-Algorithm
sensor	I-Algorithm
is	O
amplified	O
,	O
which	O
at	O
the	O
same	O
time	O
increases	O
the	O
noise	B-Algorithm
level	O
,	O
leading	O
to	O
a	O
lower	O
signal-to-noise	O
ratio	O
.	O
</s>
<s>
The	O
image	B-Algorithm
processor	I-Algorithm
attempts	O
to	O
separate	O
the	O
noise	B-Algorithm
from	O
the	O
image	O
information	O
and	O
to	O
remove	O
it	O
.	O
</s>
<s>
This	O
can	O
be	O
quite	O
a	O
challenge	O
,	O
as	O
the	O
image	O
may	O
contain	O
areas	O
with	O
fine	O
textures	O
which	O
,	O
if	O
treated	O
as	O
noise	B-Algorithm
,	O
may	O
lose	O
some	O
of	O
their	O
definition	O
.	O
</s>
<s>
As	O
the	O
color	O
and	O
brightness	O
values	O
for	O
each	O
pixel	B-Algorithm
are	O
interpolated	O
some	O
image	O
sharpening	O
is	O
applied	O
to	O
even	O
out	O
any	O
fuzziness	O
that	O
has	O
occurred	O
.	O
</s>
<s>
To	O
preserve	O
the	O
impression	O
of	O
depth	O
,	O
clarity	O
and	O
fine	O
details	O
,	O
the	O
image	B-Algorithm
processor	I-Algorithm
must	O
sharpen	O
edges	O
and	O
contours	O
.	O
</s>
<s>
It	O
therefore	O
must	O
detect	B-Algorithm
edges	I-Algorithm
correctly	O
and	O
reproduce	O
them	O
smoothly	O
and	O
without	O
over-sharpening	O
.	O
</s>
<s>
Image	B-Algorithm
processor	I-Algorithm
users	O
are	O
using	O
industry	O
standard	O
products	O
,	O
application-specific	O
standard	O
products	O
(	O
ASSP	O
)	O
or	O
even	O
application-specific	O
integrated	O
circuits	O
(	O
ASIC	O
)	O
with	O
trade	O
names	O
:	O
Canon	O
's	O
is	O
called	O
DIGIC	B-General_Concept
,	O
Nikon	O
's	O
Expeed	B-Algorithm
,	O
Olympus	O
 '	O
TruePic	O
,	O
Panasonic	O
's	O
Venus	B-Application
Engine	I-Application
and	O
Sony	O
's	O
Bionz	B-Device
.	O
</s>
<s>
Some	O
are	O
known	O
to	O
be	O
based	O
on	O
the	O
Fujitsu	O
Milbeaut	B-General_Concept
,	O
the	O
Texas	B-Device
Instruments	I-Device
OMAP	I-Device
,	O
Panasonic	O
MN103	B-General_Concept
,	O
Zoran	O
Coach	O
,	O
Altek	O
Sunny	O
or	O
Sanyo	O
image/video	O
processors	O
.	O
</s>
<s>
ARM	B-Architecture
architecture	I-Architecture
processors	O
with	O
its	O
NEON	O
SIMD	B-Device
Media	B-General_Concept
Processing	I-General_Concept
Engines	I-General_Concept
(	O
MPE	O
)	O
are	O
often	O
used	O
in	O
mobile	O
phones	O
.	O
</s>
<s>
With	O
the	O
ever-higher	O
pixel	B-Algorithm
count	O
in	O
image	B-Algorithm
sensors	I-Algorithm
,	O
the	O
image	B-Algorithm
processor	I-Algorithm
's	O
speed	O
becomes	O
more	O
critical	O
:	O
photographers	O
do	O
n't	O
want	O
to	O
wait	O
for	O
the	O
camera	O
's	O
image	B-Algorithm
processor	I-Algorithm
to	O
complete	O
its	O
job	O
before	O
they	O
can	O
carry	O
on	O
shooting	O
-	O
they	O
do	O
n't	O
even	O
want	O
to	O
notice	O
some	O
processing	O
is	O
going	O
on	O
inside	O
the	O
camera	O
.	O
</s>
<s>
Therefore	O
,	O
image	B-General_Concept
processors	I-General_Concept
must	O
be	O
optimised	O
to	O
cope	O
with	O
more	O
data	O
in	O
the	O
same	O
or	O
even	O
a	O
shorter	O
period	O
of	O
time	O
.	O
</s>
<s>
libcamera	O
is	O
a	O
software	O
library	O
that	O
supports	O
using	O
image	B-General_Concept
signal	I-General_Concept
processors	I-General_Concept
for	O
the	O
capture	O
of	O
pictures	O
.	O
</s>
