<s>
A	O
Bayer	B-Algorithm
filter	I-Algorithm
mosaic	O
is	O
a	O
color	B-Algorithm
filter	I-Algorithm
array	I-Algorithm
(	O
CFA	O
)	O
for	O
arranging	O
RGB	O
color	O
filters	O
on	O
a	O
square	O
grid	O
of	O
photosensors	O
.	O
</s>
<s>
Its	O
particular	O
arrangement	O
of	O
color	O
filters	O
is	O
used	O
in	O
most	O
single-chip	O
digital	B-Algorithm
image	I-Algorithm
sensors	I-Algorithm
used	O
in	O
digital	O
cameras	O
,	O
camcorders	O
,	O
and	O
scanners	O
to	O
create	O
a	O
color	O
image	O
.	O
</s>
<s>
The	O
filter	O
pattern	O
is	O
half	O
green	O
,	O
one	O
quarter	O
red	O
and	O
one	O
quarter	O
blue	O
,	O
hence	O
is	O
also	O
called	O
BGGR	O
,	O
RGBG	B-Algorithm
,	O
GRBG	O
,	O
or	O
RGGB	O
.	O
</s>
<s>
Bayer	O
is	O
also	O
known	O
for	O
his	O
recursively	O
defined	O
matrix	O
used	O
in	O
ordered	B-Algorithm
dithering	I-Algorithm
.	O
</s>
<s>
Alternatives	O
to	O
the	O
Bayer	B-Algorithm
filter	I-Algorithm
include	O
both	O
various	O
modifications	O
of	O
colors	O
and	O
arrangement	O
and	O
completely	O
different	O
technologies	O
,	O
such	O
as	O
color	B-Algorithm
co-site	I-Algorithm
sampling	I-Algorithm
,	O
the	O
Foveon	B-Algorithm
X3	I-Algorithm
sensor	I-Algorithm
,	O
the	O
dichroic	O
mirrors	O
or	O
a	O
transparent	O
diffractive-filter	O
array	O
.	O
</s>
<s>
These	O
elements	O
are	O
referred	O
to	O
as	O
sensor	O
elements	O
,	O
sensels	O
,	O
pixel	B-Algorithm
sensors	O
,	O
or	O
simply	O
pixels	B-Algorithm
;	O
sample	O
values	O
sensed	O
by	O
them	O
,	O
after	O
interpolation	B-Algorithm
,	O
become	O
image	O
pixels	B-Algorithm
.	O
</s>
<s>
At	O
the	O
time	O
Bayer	O
registered	O
his	O
patent	O
,	O
he	O
also	O
proposed	O
to	O
use	O
a	O
cyan-magenta-yellow	O
combination	O
,	O
that	O
is	O
another	O
set	O
of	O
opposite	O
colors	O
.	O
</s>
<s>
The	O
raw	B-Application
output	O
of	O
Bayer-filter	O
cameras	O
is	O
referred	O
to	O
as	O
a	O
Bayer	B-Algorithm
pattern	I-Algorithm
image	O
.	O
</s>
<s>
Since	O
each	O
pixel	B-Algorithm
is	O
filtered	O
to	O
record	O
only	O
one	O
of	O
three	O
colors	O
,	O
the	O
data	O
from	O
each	O
pixel	B-Algorithm
cannot	O
fully	O
specify	O
each	O
of	O
the	O
red	O
,	O
green	O
,	O
and	O
blue	O
values	O
on	O
its	O
own	O
.	O
</s>
<s>
To	O
obtain	O
a	O
full-color	O
image	O
,	O
various	O
demosaicing	B-Algorithm
algorithms	O
can	O
be	O
used	O
to	O
interpolate	B-Algorithm
a	O
set	O
of	O
complete	O
red	O
,	O
green	O
,	O
and	O
blue	O
values	O
for	O
each	O
pixel	B-Algorithm
.	O
</s>
<s>
These	O
algorithms	O
make	O
use	O
of	O
the	O
surrounding	O
pixels	B-Algorithm
of	O
the	O
corresponding	O
colors	O
to	O
estimate	O
the	O
values	O
for	O
a	O
particular	O
pixel	B-Algorithm
.	O
</s>
<s>
This	O
can	O
be	O
done	O
in-camera	O
,	O
producing	O
a	O
JPEG	O
or	O
TIFF	O
image	O
,	O
or	O
outside	O
the	O
camera	O
using	O
the	O
raw	B-Application
data	O
directly	O
from	O
the	O
sensor	O
.	O
</s>
<s>
Recording	O
in	O
Raw-format	O
provides	O
the	O
ability	O
to	O
manually	O
select	O
demosaicing	B-Algorithm
algorithm	O
and	O
control	O
the	O
transformation	O
parameters	O
,	O
which	O
is	O
used	O
not	O
only	O
in	O
consumer	O
photography	O
but	O
also	O
in	O
solving	O
various	O
technical	O
and	O
photometric	O
problems	O
.	O
</s>
<s>
Demosaicing	B-Algorithm
can	O
be	O
performed	O
in	O
different	O
ways	O
.	O
</s>
<s>
Simple	O
methods	O
interpolate	B-Algorithm
the	O
color	O
value	O
of	O
the	O
pixels	B-Algorithm
of	O
the	O
same	O
color	O
in	O
the	O
neighborhood	O
.	O
</s>
<s>
For	O
example	O
,	O
once	O
the	O
chip	O
has	O
been	O
exposed	O
to	O
an	O
image	O
,	O
each	O
pixel	B-Algorithm
can	O
be	O
read	O
.	O
</s>
<s>
A	O
pixel	B-Algorithm
with	O
a	O
green	O
filter	O
provides	O
an	O
exact	O
measurement	O
of	O
the	O
green	O
component	O
.	O
</s>
<s>
The	O
red	O
and	O
blue	O
components	O
for	O
this	O
pixel	B-Algorithm
are	O
obtained	O
from	O
the	O
neighbors	O
.	O
</s>
<s>
For	O
a	O
green	O
pixel	B-Algorithm
,	O
two	O
red	O
neighbors	O
can	O
be	O
interpolated	O
to	O
yield	O
the	O
red	O
value	O
,	O
also	O
two	O
blue	O
pixels	B-Algorithm
can	O
be	O
interpolated	O
to	O
yield	O
the	O
blue	O
value	O
.	O
</s>
<s>
Because	O
of	O
this	O
,	O
other	O
demosaicing	B-Algorithm
methods	O
attempt	O
to	O
identify	O
high-contrast	O
edges	O
and	O
only	O
interpolate	B-Algorithm
along	O
these	O
edges	O
,	O
but	O
not	O
across	O
them	O
.	O
</s>
<s>
Images	O
with	O
small-scale	O
detail	O
close	O
to	O
the	O
resolution	O
limit	O
of	O
the	O
digital	O
sensor	O
can	O
be	O
a	O
problem	O
to	O
the	O
demosaicing	B-Algorithm
algorithm	O
,	O
producing	O
a	O
result	O
which	O
does	O
not	O
look	O
like	O
the	O
model	O
.	O
</s>
<s>
The	O
most	O
frequent	O
artifact	O
is	O
Moiré	O
,	O
which	O
may	O
appear	O
as	O
repeating	O
patterns	O
,	O
color	O
artifacts	O
or	O
pixels	B-Algorithm
arranged	O
in	O
an	O
unrealistic	O
maze-like	O
pattern	O
.	O
</s>
<s>
A	O
common	O
and	O
unfortunate	O
artifact	O
of	O
Color	B-Algorithm
Filter	I-Algorithm
Array	I-Algorithm
(	O
CFA	O
)	O
interpolation	B-Algorithm
or	O
demosaicing	B-Algorithm
is	O
what	O
is	O
known	O
and	O
seen	O
as	O
false	O
coloring	O
.	O
</s>
<s>
Smooth	O
hue	O
transition	O
interpolation	B-Algorithm
is	O
used	O
during	O
the	O
demosaicing	B-Algorithm
to	O
prevent	O
false	O
colors	O
from	O
manifesting	O
themselves	O
in	O
the	O
final	O
image	O
.	O
</s>
<s>
However	O
,	O
there	O
are	O
other	O
algorithms	O
that	O
can	O
remove	O
false	O
colors	O
after	O
demosaicing	B-Algorithm
.	O
</s>
<s>
These	O
have	O
the	O
benefit	O
of	O
removing	O
false	O
coloring	O
artifacts	O
from	O
the	O
image	O
while	O
using	O
a	O
more	O
robust	O
demosaicing	B-Algorithm
algorithm	O
for	O
interpolating	O
the	O
red	O
and	O
blue	O
color	O
planes	O
.	O
</s>
<s>
The	O
zippering	O
artifact	O
is	O
another	O
side	O
effect	O
of	O
CFA	O
demosaicing	B-Algorithm
,	O
which	O
also	O
occurs	O
primarily	O
along	O
edges	O
,	O
is	O
known	O
as	O
the	O
zipper	O
effect	O
.	O
</s>
<s>
This	O
effect	O
occurs	O
when	O
the	O
demosaicing	B-Algorithm
algorithm	O
averages	O
pixel	B-Algorithm
values	O
over	O
an	O
edge	O
,	O
especially	O
in	O
the	O
red	O
and	O
blue	O
planes	O
,	O
resulting	O
in	O
its	O
characteristic	O
blur	O
.	O
</s>
<s>
As	O
mentioned	O
before	O
,	O
the	O
best	O
methods	O
for	O
preventing	O
this	O
effect	O
are	O
the	O
various	O
algorithms	O
which	O
interpolate	B-Algorithm
along	O
,	O
rather	O
than	O
across	O
image	O
edges	O
.	O
</s>
<s>
Pattern	O
recognition	O
interpolation	B-Algorithm
,	O
adaptive	O
color	O
plane	O
interpolation	B-Algorithm
,	O
and	O
directionally	O
weighted	O
interpolation	B-Algorithm
all	O
attempt	O
to	O
prevent	O
zippering	O
by	O
interpolating	O
along	O
edges	O
detected	O
in	O
the	O
image	O
.	O
</s>
<s>
However	O
,	O
even	O
with	O
a	O
theoretically	O
perfect	O
sensor	O
that	O
could	O
capture	O
and	O
distinguish	O
all	O
colors	O
at	O
each	O
photosite	B-Algorithm
,	O
Moiré	O
and	O
other	O
artifacts	O
could	O
still	O
appear	O
.	O
</s>
<s>
The	O
Bayer	B-Algorithm
filter	I-Algorithm
is	O
almost	O
universal	O
on	O
consumer	O
digital	O
cameras	O
.	O
</s>
<s>
Alternatives	O
include	O
the	O
CYGM	B-Algorithm
filter	I-Algorithm
(	O
cyan	O
,	O
yellow	O
,	O
green	O
,	O
magenta	B-Algorithm
)	O
and	O
RGBE	B-Algorithm
filter	I-Algorithm
(	O
red	O
,	O
green	O
,	O
blue	O
,	O
emerald	O
)	O
,	O
which	O
require	O
similar	O
demosaicing	B-Algorithm
.	O
</s>
<s>
The	O
Foveon	B-Algorithm
X3	I-Algorithm
sensor	I-Algorithm
(	O
which	O
layers	O
red	O
,	O
green	O
,	O
and	O
blue	O
sensors	O
vertically	O
rather	O
than	O
using	O
a	O
mosaic	O
)	O
and	O
arrangements	O
of	O
three	B-Algorithm
separate	I-Algorithm
CCDs	I-Algorithm
(	O
one	O
for	O
each	O
color	O
)	O
does	O
n't	O
need	O
demosaicing	B-Algorithm
.	O
</s>
<s>
On	O
June	O
14	O
,	O
2007	O
,	O
Eastman	O
Kodak	O
announced	O
an	O
alternative	O
to	O
the	O
Bayer	B-Algorithm
filter	I-Algorithm
:	O
a	O
colour-filter	O
pattern	O
that	O
increases	O
the	O
sensitivity	O
to	O
light	O
of	O
the	O
image	B-Algorithm
sensor	I-Algorithm
in	O
a	O
digital	O
camera	O
by	O
using	O
some	O
"	O
panchromatic	O
"	O
cells	O
that	O
are	O
sensitive	O
to	O
all	O
wavelengths	O
of	O
visible	O
light	O
and	O
collect	O
a	O
larger	O
amount	O
of	O
light	O
striking	O
the	O
sensor	O
.	O
</s>
<s>
They	O
present	O
several	O
patterns	O
,	O
but	O
none	O
with	O
a	O
repeating	O
unit	O
as	O
small	O
as	O
the	O
Bayer	B-Algorithm
pattern	I-Algorithm
's	O
2×2	O
unit	O
.	O
</s>
<s>
Another	O
2007	O
U.S.	O
patent	O
filing	O
,	O
by	O
Edward	O
T	O
.	O
Chang	O
,	O
claims	O
a	O
sensor	O
where	O
"	O
the	O
color	O
filter	O
has	O
a	O
pattern	O
comprising	O
2×2	O
blocks	O
of	O
pixels	B-Algorithm
composed	O
of	O
one	O
red	O
,	O
one	O
blue	O
,	O
one	O
green	O
and	O
one	O
transparent	O
pixel	B-Algorithm
,	O
"	O
in	O
a	O
configuration	O
intended	O
to	O
include	O
infrared	O
sensitivity	O
for	O
higher	O
overall	O
sensitivity	O
.	O
</s>
<s>
Such	O
cells	O
have	O
previously	O
been	O
used	O
in	O
"	O
CMYW	O
"	O
(	O
cyan	O
,	O
magenta	B-Algorithm
,	O
yellow	O
,	O
and	O
white	O
)	O
"	O
RGBW	O
"	O
(	O
red	O
,	O
green	O
,	O
blue	O
,	O
white	O
)	O
sensors	O
,	O
but	O
Kodak	O
has	O
not	O
compared	O
the	O
new	O
filter	O
pattern	O
to	O
them	O
yet	O
.	O
</s>
<s>
Fujifilm	O
's	O
EXR	O
color	B-Algorithm
filter	I-Algorithm
array	I-Algorithm
are	O
manufactured	O
in	O
both	O
CCD	O
(	O
SuperCCD	B-Algorithm
)	O
and	O
CMOS	B-Architecture
(	O
BSI	O
CMOS	B-Architecture
)	O
.	O
</s>
<s>
As	O
with	O
the	O
SuperCCD	B-Algorithm
,	O
the	O
filter	O
itself	O
is	O
rotated	O
45	O
degrees	O
.	O
</s>
<s>
Unlike	O
conventional	O
Bayer	B-Algorithm
filter	I-Algorithm
designs	O
,	O
there	O
are	O
always	O
two	O
adjacent	O
photosites	B-Algorithm
detecting	O
the	O
same	O
color	O
.	O
</s>
<s>
The	O
main	O
reason	O
for	O
this	O
type	O
of	O
array	O
is	O
to	O
contribute	O
to	O
pixel	B-Algorithm
"	O
binning	O
"	O
,	O
where	O
two	O
adjacent	O
photosites	B-Algorithm
can	O
be	O
merged	O
,	O
making	O
the	O
sensor	O
itself	O
more	O
"	O
sensitive	O
"	O
to	O
light	O
.	O
</s>
<s>
The	O
result	O
is	O
that	O
it	O
can	O
act	O
like	O
two	O
interleaved	O
sensors	O
,	O
with	O
different	O
exposure	O
times	O
for	O
each	O
half	O
of	O
the	O
photosites	B-Algorithm
.	O
</s>
<s>
Half	O
of	O
the	O
photosites	B-Algorithm
can	O
be	O
intentionally	O
underexposed	O
so	O
that	O
they	O
fully	O
capture	O
the	O
brighter	O
areas	O
of	O
the	O
scene	O
.	O
</s>
<s>
This	O
retained	O
highlight	O
information	O
can	O
then	O
be	O
blended	O
in	O
with	O
the	O
output	O
from	O
the	O
other	O
half	O
of	O
the	O
sensor	O
that	O
is	O
recording	O
a	O
'	O
full	O
 '	O
exposure	O
,	O
again	O
making	O
use	O
of	O
the	O
close	O
spacing	O
of	O
similarly	O
colored	O
photosites	B-Algorithm
.	O
</s>
<s>
The	O
Fujifilm	O
X-Trans	O
CMOS	B-Architecture
sensor	I-Architecture
used	O
in	O
many	O
Fujifilm	B-Device
X-series	I-Device
cameras	O
is	O
claimed	O
to	O
provide	O
better	O
resistance	O
to	O
color	O
moiré	O
than	O
the	O
Bayer	B-Algorithm
filter	I-Algorithm
,	O
and	O
as	O
such	O
they	O
can	O
be	O
made	O
without	O
an	O
anti-aliasing	O
filter	O
.	O
</s>
<s>
Also	O
,	O
the	O
new	O
design	O
is	O
claimed	O
to	O
reduce	O
the	O
incidence	O
of	O
false	O
colors	O
,	O
by	O
having	O
red	O
,	O
blue	O
and	O
green	O
pixels	B-Algorithm
in	O
each	O
line	O
.	O
</s>
<s>
The	O
arrangement	O
of	O
these	O
pixels	B-Algorithm
is	O
also	O
said	O
to	O
provide	O
grain	O
more	O
like	O
film	O
.	O
</s>
<s>
One	O
of	O
main	O
drawbacks	O
for	O
custom	O
patterns	O
is	O
that	O
they	O
may	O
lack	O
full	O
support	O
in	O
third	O
party	O
raw	B-Application
processing	O
software	O
like	O
Adobe	B-Operating_System
Photoshop	I-Operating_System
Lightroom	I-Operating_System
where	O
adding	O
improvements	O
took	O
multiple	O
years	O
.	O
</s>
<s>
Sony	O
introduced	O
Quad	O
Bayer	B-Algorithm
color	I-Algorithm
filter	I-Algorithm
array	O
,	O
which	O
first	O
featured	O
in	O
the	O
Huawei	B-Application
P20	I-Application
Pro	I-Application
released	O
on	O
March	O
27	O
,	O
2018	O
.	O
</s>
<s>
Quad	O
Bayer	O
is	O
similar	O
to	O
Bayer	B-Algorithm
filter	I-Algorithm
,	O
however	O
adjacent	O
2x2	O
pixels	B-Algorithm
are	O
the	O
same	O
color	O
,	O
the	O
4x4	O
pattern	O
features	O
4x	O
blue	O
,	O
4x	O
red	O
,	O
and	O
8x	O
green	O
.	O
</s>
<s>
For	O
darker	O
scenes	O
,	O
signal	O
processing	O
can	O
combine	O
data	O
from	O
each	O
2x2	O
group	O
,	O
essentially	O
like	O
a	O
larger	O
pixel	B-Algorithm
.	O
</s>
<s>
For	O
brighter	O
scenes	O
,	O
signal	O
processing	O
can	O
convert	O
the	O
Quad	O
Bayer	O
into	O
a	O
conventional	O
Bayer	B-Algorithm
filter	I-Algorithm
to	O
achieve	O
higher	O
resolution	O
.	O
</s>
<s>
The	O
pixels	B-Algorithm
in	O
Quad	O
Bayer	O
can	O
be	O
operated	O
in	O
long-time	O
integration	O
and	O
short-time	O
integration	O
to	O
achieve	O
single	O
shot	O
HDR	O
,	O
reducing	O
blending	O
issues	O
.	O
</s>
<s>
Quad	O
Bayer	O
is	O
also	O
known	O
as	O
Tetracell	B-Architecture
by	O
Samsung	B-Application
,	O
4-cell	O
by	O
OmniVision	O
,	O
and	O
Quad	O
CFA	O
(	O
QCFA	O
)	O
by	O
Qualcomm	O
.	O
</s>
<s>
On	O
March	O
26	O
,	O
2019	O
,	O
the	O
Huawei	B-Application
P30	I-Application
series	I-Application
were	O
announced	O
featuring	O
RYYB	O
Quad	O
Bayer	O
,	O
with	O
the	O
4x4	O
pattern	O
featuring	O
4x	O
blue	O
,	O
4x	O
red	O
,	O
and	O
8x	O
yellow	O
.	O
</s>
<s>
On	O
February	O
12	O
,	O
2020	O
,	O
the	O
Samsung	B-Application
Galaxy	I-Application
S20	I-Application
Ultra	I-Application
was	O
announced	O
featuring	O
Nonacell	O
CFA	O
.	O
</s>
<s>
Nonacell	O
CFA	O
is	O
similar	O
to	O
Bayer	B-Algorithm
filter	I-Algorithm
,	O
however	O
adjacent	O
3x3	O
pixels	B-Algorithm
are	O
the	O
same	O
color	O
,	O
the	O
6x6	O
pattern	O
features	O
9x	O
blue	O
,	O
9x	O
red	O
,	O
and	O
18x	O
green	O
.	O
</s>
