<s>
In	O
digital	B-Algorithm
imaging	I-Algorithm
,	O
a	O
pixel	B-Algorithm
(	O
abbreviated	O
px	O
)	O
,	O
pel	O
,	O
or	O
picture	B-Algorithm
element	I-Algorithm
is	O
the	O
smallest	O
addressable	O
element	O
in	O
a	O
raster	B-Algorithm
image	I-Algorithm
,	O
or	O
the	O
smallest	O
addressable	O
element	O
in	O
a	O
dot	B-General_Concept
matrix	I-General_Concept
display	B-Device
device	I-Device
.	O
</s>
<s>
In	O
most	O
digital	B-Device
display	I-Device
devices	O
,	O
pixels	B-Algorithm
are	O
the	O
smallest	O
element	O
that	O
can	O
be	O
manipulated	O
through	O
software	O
.	O
</s>
<s>
Each	O
pixel	B-Algorithm
is	O
a	O
sample	B-Algorithm
of	O
an	O
original	O
or	O
synthetic	O
image	O
;	O
more	O
samples	B-Algorithm
typically	O
provide	O
more	O
accurate	O
representations	O
of	O
the	O
original	O
.	O
</s>
<s>
The	O
intensity	O
of	O
each	O
pixel	B-Algorithm
is	O
variable	O
.	O
</s>
<s>
In	O
some	O
contexts	O
(	O
such	O
as	O
descriptions	O
of	O
camera	B-Algorithm
sensors	I-Algorithm
)	O
,	O
pixel	B-Algorithm
refers	O
to	O
a	O
single	O
scalar	O
element	O
of	O
a	O
multi-component	O
representation	O
(	O
called	O
a	O
photosite	B-Algorithm
in	O
the	O
camera	B-Algorithm
sensor	I-Algorithm
context	O
,	O
although	O
sensel	O
is	O
sometimes	O
used	O
)	O
,	O
while	O
in	O
yet	O
other	O
contexts	O
(	O
like	O
MRI	O
)	O
it	O
may	O
refer	O
to	O
a	O
set	O
of	O
component	O
intensities	O
for	O
a	O
spatial	O
position	O
.	O
</s>
<s>
Software	O
on	O
early	O
consumer	O
computers	O
was	O
necessarily	O
rendered	O
at	O
a	O
low	B-Algorithm
resolution	I-Algorithm
,	O
with	O
large	O
pixels	B-Algorithm
visible	O
to	O
the	O
naked	O
eye	O
;	O
graphics	O
made	O
under	O
these	O
limitations	O
may	O
be	O
called	O
pixel	B-Algorithm
art	O
,	O
especially	O
in	O
reference	O
to	O
video	O
games	O
.	O
</s>
<s>
Modern	O
computers	O
and	O
displays	O
,	O
however	O
,	O
can	O
easily	O
render	O
orders	O
of	O
magnitude	O
more	O
pixels	B-Algorithm
than	O
was	O
previously	O
possible	O
,	O
necessitating	O
the	O
use	O
of	O
large	O
measurements	O
like	O
the	O
megapixel	O
(	O
one	O
million	O
pixels	B-Algorithm
)	O
.	O
</s>
<s>
The	O
word	O
pixel	B-Algorithm
is	O
a	O
combination	O
of	O
pix	O
(	O
from	O
"	O
pictures	O
"	O
,	O
shortened	O
to	O
"	O
pics	O
"	O
)	O
and	O
el	O
(	O
for	O
"	O
element	O
"	O
)	O
;	O
similar	O
formations	O
with	O
'	O
el	O
include	O
the	O
words	O
voxel	B-Algorithm
and	O
texel	O
.	O
</s>
<s>
The	O
word	O
"	O
pixel	B-Algorithm
"	O
was	O
first	O
published	O
in	O
1965	O
by	O
Frederic	O
C	O
.	O
Billingsley	O
of	O
JPL	O
,	O
to	O
describe	O
the	O
picture	B-Algorithm
elements	I-Algorithm
of	O
scanned	O
images	O
from	O
space	O
probes	O
to	O
the	O
Moon	O
and	O
Mars.Fred	O
C	O
.	O
Billingsley	O
,	O
"	O
Processing	O
Ranger	O
and	O
Mariner	O
Photography	O
,	O
"	O
in	O
Computerized	O
Imaging	O
Techniques	O
,	O
Proceedings	O
of	O
SPIE	O
,	O
Vol	O
.	O
</s>
<s>
The	O
concept	O
of	O
a	O
"	O
picture	B-Algorithm
element	I-Algorithm
"	O
dates	O
to	O
the	O
earliest	O
days	O
of	O
television	O
,	O
for	O
example	O
as	O
"	O
Bildpunkt	O
"	O
(	O
the	O
German	O
word	O
for	O
pixel	B-Algorithm
,	O
literally	O
'	O
picture	O
point	O
 '	O
)	O
in	O
the	O
1888	O
German	O
patent	O
of	O
Paul	O
Nipkow	O
.	O
</s>
<s>
According	O
to	O
various	O
etymologies	O
,	O
the	O
earliest	O
publication	O
of	O
the	O
term	O
picture	B-Algorithm
element	I-Algorithm
itself	O
was	O
in	O
Wireless	O
World	O
magazine	O
in	O
1927	O
,	O
though	O
it	O
had	O
been	O
used	O
earlier	O
in	O
various	O
U.S.	O
patents	O
filed	O
as	O
early	O
as	O
1911	O
.	O
</s>
<s>
Some	O
authors	O
explain	O
pixel	B-Algorithm
as	O
picture	O
cell	O
,	O
as	O
early	O
as	O
1972	O
.	O
</s>
<s>
In	O
graphics	O
and	O
in	O
image	O
and	O
video	O
processing	O
,	O
pel	O
is	O
often	O
used	O
instead	O
of	O
pixel	B-Algorithm
.	O
</s>
<s>
For	O
example	O
,	O
IBM	O
used	O
it	O
in	O
their	O
Technical	O
Reference	O
for	O
the	O
original	B-Device
PC	I-Device
.	O
</s>
<s>
An	O
archaic	O
British	O
word	O
meaning	O
"	O
possession	O
by	O
spirits	O
(	O
pixies	B-Application
)	O
"	O
,	O
the	O
term	O
has	O
been	O
used	O
to	O
describe	O
the	O
animation	O
process	O
since	O
the	O
early	O
1950s	O
;	O
various	O
animators	O
,	O
including	O
Norman	O
McLaren	O
and	O
Grant	O
Munro	O
,	O
are	O
credited	O
with	O
popularizing	O
it	O
.	O
</s>
<s>
right|frame|A	O
pixel	B-Algorithm
does	O
not	O
need	O
to	O
be	O
rendered	O
as	O
a	O
small	O
square	O
.	O
</s>
<s>
This	O
image	O
shows	O
alternative	O
ways	O
of	O
reconstructing	O
an	O
image	O
from	O
a	O
set	O
of	O
pixel	B-Algorithm
values	O
,	O
using	O
dots	O
,	O
lines	O
,	O
or	O
smooth	O
filtering	O
.	O
</s>
<s>
thought	O
of	O
as	O
the	O
smallest	O
single	O
component	O
of	O
a	O
digital	B-Algorithm
image	I-Algorithm
.	O
</s>
<s>
For	O
example	O
,	O
there	O
can	O
be	O
"	O
printed	O
pixels	B-Algorithm
"	O
in	O
a	O
page	O
,	O
or	O
pixels	B-Algorithm
carried	O
by	O
electronic	O
signals	O
,	O
or	O
represented	O
by	O
digital	O
values	O
,	O
or	O
pixels	B-Algorithm
on	O
a	O
display	B-Device
device	I-Device
,	O
or	O
pixels	B-Algorithm
in	O
a	O
digital	B-Device
camera	I-Device
(	O
photosensor	O
elements	O
)	O
.	O
</s>
<s>
This	O
list	O
is	O
not	O
exhaustive	O
and	O
,	O
depending	O
on	O
context	O
,	O
synonyms	O
include	O
pel	O
,	O
sample	B-Algorithm
,	O
byte	O
,	O
bit	O
,	O
dot	O
,	O
and	O
spot	O
.	O
</s>
<s>
Pixels	B-Algorithm
can	O
be	O
used	O
as	O
a	O
unit	O
of	O
measure	O
such	O
as	O
:	O
2400	O
pixels	B-Algorithm
per	I-Algorithm
inch	I-Algorithm
,	O
640	O
pixels	B-Algorithm
per	O
line	O
,	O
or	O
spaced	O
10	O
pixels	B-Algorithm
apart	O
.	O
</s>
<s>
The	O
measures	O
"	O
dots	O
per	O
inch	O
"	O
(	O
dpi	O
)	O
and	O
"	O
pixels	B-Algorithm
per	I-Algorithm
inch	I-Algorithm
"	O
(	O
ppi	O
)	O
are	O
sometimes	O
used	O
interchangeably	O
,	O
but	O
have	O
distinct	O
meanings	O
,	O
especially	O
for	O
printer	O
devices	O
,	O
where	O
dpi	O
is	O
a	O
measure	O
of	O
the	O
printer	O
's	O
density	O
of	O
dot	O
(	O
e.g.	O
</s>
<s>
Even	O
higher	O
dpi	O
numbers	O
,	O
such	O
as	O
the	O
4800	O
dpi	O
quoted	O
by	O
printer	O
manufacturers	O
since	O
2002	O
,	O
do	O
not	O
mean	O
much	O
in	O
terms	O
of	O
achievable	O
resolution	B-Algorithm
.	O
</s>
<s>
The	O
more	O
pixels	B-Algorithm
used	O
to	O
represent	O
an	O
image	O
,	O
the	O
closer	O
the	O
result	O
can	O
resemble	O
the	O
original	O
.	O
</s>
<s>
The	O
number	O
of	O
pixels	B-Algorithm
in	O
an	O
image	O
is	O
sometimes	O
called	O
the	O
resolution	B-Algorithm
,	O
though	O
resolution	B-Algorithm
has	O
a	O
more	O
specific	O
definition	O
.	O
</s>
<s>
Pixel	B-Algorithm
counts	O
can	O
be	O
expressed	O
as	O
a	O
single	O
number	O
,	O
as	O
in	O
a	O
"	O
three-megapixel	O
"	O
digital	B-Device
camera	I-Device
,	O
which	O
has	O
a	O
nominal	O
three	O
million	O
pixels	B-Algorithm
,	O
or	O
as	O
a	O
pair	O
of	O
numbers	O
,	O
as	O
in	O
a	O
"	O
640	O
by	O
480	O
display	O
"	O
,	O
which	O
has	O
640	O
pixels	B-Algorithm
from	O
side	O
to	O
side	O
and	O
480	O
from	O
top	O
to	O
bottom	O
(	O
as	O
in	O
a	O
VGA	B-Protocol
display	O
)	O
and	O
therefore	O
has	O
a	O
total	O
number	O
of	O
640	O
×	O
480	O
=	O
307,200	O
pixels	B-Algorithm
,	O
or	O
0.3	O
megapixels	O
.	O
</s>
<s>
The	O
pixels	B-Algorithm
,	O
or	O
color	O
samples	B-Algorithm
,	O
that	O
form	O
a	O
digitized	B-Algorithm
image	I-Algorithm
(	O
such	O
as	O
a	O
JPEG	O
file	O
used	O
on	O
a	O
web	O
page	O
)	O
may	O
or	O
may	O
not	O
be	O
in	O
one-to-one	B-Algorithm
correspondence	I-Algorithm
with	O
screen	O
pixels	B-Algorithm
,	O
depending	O
on	O
how	O
a	O
computer	B-Device
displays	I-Device
an	O
image	O
.	O
</s>
<s>
In	O
computing	O
,	O
an	O
image	O
composed	O
of	O
pixels	B-Algorithm
is	O
known	O
as	O
a	O
bitmapped	B-Algorithm
image	I-Algorithm
or	O
a	O
raster	B-Algorithm
image	I-Algorithm
.	O
</s>
<s>
For	O
convenience	O
,	O
pixels	B-Algorithm
are	O
normally	O
arranged	O
in	O
a	O
regular	O
two-dimensional	O
grid	O
.	O
</s>
<s>
By	O
using	O
this	O
arrangement	O
,	O
many	O
common	O
operations	O
can	O
be	O
implemented	O
by	O
uniformly	O
applying	O
the	O
same	O
operation	O
to	O
each	O
pixel	B-Algorithm
independently	O
.	O
</s>
<s>
Other	O
arrangements	O
of	O
pixels	B-Algorithm
are	O
possible	O
,	O
with	O
some	O
sampling	O
patterns	O
even	O
changing	O
the	O
shape	O
(	O
or	O
kernel	O
)	O
of	O
each	O
pixel	B-Algorithm
across	O
the	O
image	O
.	O
</s>
<s>
For	O
this	O
reason	O
,	O
care	O
must	O
be	O
taken	O
when	O
acquiring	O
an	O
image	O
on	O
one	O
device	O
and	O
displaying	O
it	O
on	O
another	O
,	O
or	O
when	O
converting	O
image	O
data	O
from	O
one	O
pixel	B-Algorithm
format	O
to	O
another	O
.	O
</s>
<s>
LCD	B-Device
screens	I-Device
typically	O
use	O
a	O
staggered	O
grid	O
,	O
where	O
the	O
red	O
,	O
green	O
,	O
and	O
blue	O
components	O
are	O
sampled	O
at	O
slightly	O
different	O
locations	O
.	O
</s>
<s>
Subpixel	O
rendering	O
is	O
a	O
technology	O
which	O
takes	O
advantage	O
of	O
these	O
differences	O
to	O
improve	O
the	O
rendering	O
of	O
text	O
on	O
LCD	B-Device
screens	I-Device
.	O
</s>
<s>
The	O
vast	O
majority	O
of	O
color	O
digital	B-Device
cameras	I-Device
use	O
a	O
Bayer	B-Algorithm
filter	I-Algorithm
,	O
resulting	O
in	O
a	O
regular	O
grid	O
of	O
pixels	B-Algorithm
where	O
the	O
color	O
of	O
each	O
pixel	B-Algorithm
depends	O
on	O
its	O
position	O
on	O
the	O
grid	O
.	O
</s>
<s>
A	O
clipmap	B-Algorithm
uses	O
a	O
hierarchical	O
sampling	O
pattern	O
,	O
where	O
the	O
size	O
of	O
the	O
support	O
of	O
each	O
pixel	B-Algorithm
depends	O
on	O
its	O
location	O
within	O
the	O
hierarchy	O
.	O
</s>
<s>
Pixels	B-Algorithm
on	O
computer	B-Device
monitors	I-Device
are	O
normally	O
"	O
square	O
"	O
(	O
that	O
is	O
,	O
have	O
equal	O
horizontal	O
and	O
vertical	O
sampling	O
pitch	O
)	O
;	O
pixels	B-Algorithm
in	O
other	O
systems	O
are	O
often	O
"	O
rectangular	O
"	O
(	O
that	O
is	O
,	O
have	O
unequal	O
horizontal	O
and	O
vertical	O
sampling	O
pitch	O
–	O
oblong	O
in	O
shape	O
)	O
,	O
as	O
are	O
digital	O
video	O
formats	O
with	O
diverse	O
aspect	B-Device
ratios	I-Device
,	O
such	O
as	O
the	O
anamorphic	O
widescreen	O
formats	O
of	O
the	O
Rec	O
.	O
</s>
<s>
Computers	O
can	O
use	O
pixels	B-Algorithm
to	O
display	O
an	O
image	O
,	O
often	O
an	O
abstract	O
image	O
that	O
represents	O
a	O
GUI	B-Application
.	O
</s>
<s>
The	O
resolution	B-Algorithm
of	O
this	O
image	O
is	O
called	O
the	O
display	O
resolution	B-Algorithm
and	O
is	O
determined	O
by	O
the	O
video	B-Device
card	I-Device
of	O
the	O
computer	O
.	O
</s>
<s>
LCD	B-Device
monitors	I-Device
also	O
use	O
pixels	B-Algorithm
to	O
display	O
an	O
image	O
,	O
and	O
have	O
a	O
native	B-General_Concept
resolution	I-General_Concept
.	O
</s>
<s>
Each	O
pixel	B-Algorithm
is	O
made	O
up	O
of	O
triads	B-General_Concept
,	O
with	O
the	O
number	O
of	O
these	O
triads	B-General_Concept
determining	O
the	O
native	B-General_Concept
resolution	I-General_Concept
.	O
</s>
<s>
On	O
some	O
CRT	B-Device
monitors	I-Device
,	O
the	O
beam	O
sweep	O
rate	O
may	O
be	O
fixed	O
,	O
resulting	O
in	O
a	O
fixed	O
native	B-General_Concept
resolution	I-General_Concept
.	O
</s>
<s>
Most	O
CRT	B-Device
monitors	I-Device
do	O
not	O
have	O
a	O
fixed	O
beam	O
sweep	O
rate	O
,	O
meaning	O
they	O
do	O
not	O
have	O
a	O
native	B-General_Concept
resolution	I-General_Concept
at	O
all	O
-	O
instead	O
they	O
have	O
a	O
set	O
of	O
resolutions	O
that	O
are	O
equally	O
well	O
supported.To	O
produce	O
the	O
sharpest	O
images	O
possible	O
on	O
an	O
LCD	B-Device
,	O
the	O
user	O
must	O
ensure	O
the	O
display	O
resolution	B-Algorithm
of	O
the	O
computer	O
matches	O
the	O
native	B-General_Concept
resolution	I-General_Concept
of	O
the	O
monitor	O
.	O
</s>
<s>
The	O
pixel	B-Algorithm
scale	O
used	O
in	O
astronomy	O
is	O
the	O
angular	O
distance	O
between	O
two	O
objects	O
on	O
the	O
sky	O
that	O
fall	O
one	O
pixel	B-Algorithm
apart	O
on	O
the	O
detector	O
(	O
CCD	O
or	O
infrared	O
chip	O
)	O
.	O
</s>
<s>
The	O
scale	O
measured	O
in	O
radians	O
is	O
the	O
ratio	O
of	O
the	O
pixel	B-Algorithm
spacing	O
and	O
focal	B-Algorithm
length	I-Algorithm
of	O
the	O
preceding	O
optics	O
,	O
.	O
</s>
<s>
(	O
The	O
focal	B-Algorithm
length	I-Algorithm
is	O
the	O
product	O
of	O
the	O
focal	O
ratio	O
by	O
the	O
diameter	O
of	O
the	O
associated	O
lens	O
or	O
mirror	O
.	O
)	O
</s>
<s>
Because	O
is	O
usually	O
expressed	O
in	O
units	O
of	O
arcseconds	O
per	O
pixel	B-Algorithm
,	O
because	O
1	O
radian	O
equals	O
(	O
180/π	O
)	O
×	O
3600	O
≈	O
206,265	O
arcseconds	O
,	O
and	O
because	O
focal	B-Algorithm
lengths	I-Algorithm
are	O
often	O
given	O
in	O
millimeters	O
and	O
pixel	B-Algorithm
sizes	O
in	O
micrometers	O
which	O
yields	O
another	O
factor	O
of	O
1	O
,	O
000	O
,	O
the	O
formula	O
is	O
often	O
quoted	O
as	O
.	O
</s>
<s>
The	O
number	O
of	O
distinct	O
colors	O
that	O
can	O
be	O
represented	O
by	O
a	O
pixel	B-Algorithm
depends	O
on	O
the	O
number	O
of	O
bits	O
per	O
pixel	B-Algorithm
(	O
bpp	O
)	O
.	O
</s>
<s>
A	O
1	O
bpp	O
image	O
uses	O
1	O
bit	O
for	O
each	O
pixel	B-Algorithm
,	O
so	O
each	O
pixel	B-Algorithm
can	O
be	O
either	O
on	O
or	O
off	O
.	O
</s>
<s>
For	O
color	O
depths	O
of	O
15	O
or	O
more	O
bits	O
per	O
pixel	B-Algorithm
,	O
the	O
depth	O
is	O
normally	O
the	O
sum	O
of	O
the	O
bits	O
allocated	O
to	O
each	O
of	O
the	O
red	O
,	O
green	O
,	O
and	O
blue	O
components	O
.	O
</s>
<s>
On	O
some	O
systems	O
,	O
32-bit	O
depth	O
is	O
available	O
:	O
this	O
means	O
that	O
each	O
24-bit	O
pixel	B-Algorithm
has	O
an	O
extra	O
8	O
bits	O
to	O
describe	O
its	O
opacity	O
(	O
for	O
purposes	O
of	O
combining	O
with	O
another	O
image	O
)	O
.	O
</s>
<s>
thumb|upright	O
=	O
0.9	O
|Geometry	O
of	O
color	O
elements	O
of	O
various	O
CRT	B-Device
and	O
LCD	B-Device
displays	I-Device
;	O
phosphor	O
dots	O
in	O
the	O
color	B-Device
display	I-Device
of	O
CRTs	O
(	O
top	O
row	O
)	O
bear	O
no	O
relation	O
to	O
pixels	B-Algorithm
or	O
subpixels	O
.	O
</s>
<s>
Many	O
display	O
and	O
image-acquisition	O
systems	O
are	O
not	O
capable	O
of	O
displaying	O
or	O
sensing	O
the	O
different	O
color	B-Algorithm
channels	I-Algorithm
at	O
the	O
same	O
site	O
.	O
</s>
<s>
Therefore	O
,	O
the	O
pixel	B-Algorithm
grid	O
is	O
divided	O
into	O
single-color	O
regions	O
that	O
contribute	O
to	O
the	O
displayed	O
or	O
sensed	O
color	O
when	O
viewed	O
at	O
a	O
distance	O
.	O
</s>
<s>
In	O
some	O
displays	O
,	O
such	O
as	O
LCD	B-Device
,	O
LED	O
,	O
and	O
plasma	O
displays	O
,	O
these	O
single-color	O
regions	O
are	O
separately	O
addressable	O
elements	O
,	O
which	O
have	O
come	O
to	O
be	O
known	O
as	O
subpixels	O
,	O
mostly	O
RGB	O
colors	O
.	O
</s>
<s>
For	O
example	O
,	O
LCDs	B-Device
typically	O
divide	O
each	O
pixel	B-Algorithm
vertically	O
into	O
three	O
subpixels	O
.	O
</s>
<s>
When	O
the	O
square	B-Device
pixel	I-Device
is	O
divided	O
into	O
three	O
subpixels	O
,	O
each	O
subpixel	O
is	O
necessarily	O
rectangular	O
.	O
</s>
<s>
In	O
display	O
industry	O
terminology	O
,	O
subpixels	O
are	O
often	O
referred	O
to	O
as	O
pixels	B-Algorithm
,	O
as	O
they	O
are	O
the	O
basic	O
addressable	O
elements	O
in	O
a	O
viewpoint	O
of	O
hardware	O
,	O
and	O
hence	O
pixel	B-Algorithm
circuits	O
rather	O
than	O
subpixel	O
circuits	O
is	O
used	O
.	O
</s>
<s>
Most	O
digital	B-Device
camera	I-Device
image	B-Algorithm
sensors	I-Algorithm
use	O
single-color	O
sensor	O
regions	O
,	O
for	O
example	O
using	O
the	O
Bayer	B-Algorithm
filter	I-Algorithm
pattern	O
,	O
and	O
in	O
the	O
camera	O
industry	O
these	O
are	O
known	O
as	O
pixels	B-Algorithm
just	O
like	O
in	O
the	O
display	O
industry	O
,	O
not	O
subpixels	O
.	O
</s>
<s>
This	O
latter	O
approach	O
,	O
referred	O
to	O
as	O
subpixel	O
rendering	O
,	O
uses	O
knowledge	O
of	O
pixel	B-General_Concept
geometry	I-General_Concept
to	O
manipulate	O
the	O
three	O
colored	O
subpixels	O
separately	O
,	O
producing	O
an	O
increase	O
in	O
the	O
apparent	O
resolution	B-Algorithm
of	O
color	B-Device
displays	I-Device
.	O
</s>
<s>
While	O
CRT	B-Device
displays	I-Device
use	O
red-green-blue-masked	O
phosphor	O
areas	O
,	O
dictated	O
by	O
a	O
mesh	O
grid	O
called	O
the	O
shadow	O
mask	O
,	O
it	O
would	O
require	O
a	O
difficult	O
calibration	O
step	O
to	O
be	O
aligned	O
with	O
the	O
displayed	O
pixel	B-Algorithm
raster	O
,	O
and	O
so	O
CRTs	O
do	O
not	O
use	O
subpixel	O
rendering	O
.	O
</s>
<s>
The	O
concept	O
of	O
subpixels	O
is	O
related	O
to	O
samples	B-Algorithm
.	O
</s>
<s>
In	O
graphic	O
,	O
web	O
design	O
,	O
and	O
user	O
interfaces	O
,	O
a	O
"	O
pixel	B-Algorithm
"	O
may	O
refer	O
to	O
a	O
fixed	O
length	O
rather	O
than	O
a	O
true	O
pixel	B-Algorithm
on	O
the	O
screen	O
to	O
accommodate	O
different	O
pixel	B-Algorithm
densities	I-Algorithm
.	O
</s>
<s>
A	O
typical	O
definition	O
,	O
such	O
as	O
in	O
CSS	B-Language
,	O
is	O
that	O
a	O
"	O
physical	O
"	O
pixel	B-Algorithm
is	O
.	O
</s>
<s>
Doing	O
so	O
makes	O
sure	O
a	O
given	O
element	O
will	O
display	O
as	O
the	O
same	O
size	O
no	O
matter	O
what	O
screen	O
resolution	B-Algorithm
views	O
it	O
.	O
</s>
<s>
There	O
may	O
,	O
however	O
,	O
be	O
some	O
further	O
adjustments	O
between	O
a	O
"	O
physical	O
"	O
pixel	B-Algorithm
and	O
an	O
on-screen	O
logical	O
pixel	B-Algorithm
.	O
</s>
<s>
As	O
screens	O
are	O
viewed	O
at	O
difference	O
distances	O
(	O
consider	O
a	O
phone	O
,	O
a	O
computer	B-Device
display	I-Device
,	O
and	O
a	O
TV	O
)	O
,	O
the	O
desired	O
length	O
(	O
a	O
"	O
reference	O
pixel	B-Algorithm
"	O
)	O
is	O
scaled	O
relative	O
to	O
a	O
reference	O
viewing	O
distance	O
(	O
in	O
CSS	B-Language
)	O
.	O
</s>
<s>
In	O
addition	O
,	O
as	O
true	O
screen	O
pixel	B-Algorithm
densities	I-Algorithm
are	O
rarely	O
multiples	O
of	O
96	O
dpi	O
,	O
some	O
rounding	O
is	O
often	O
applied	O
so	O
that	O
a	O
logical	O
pixel	B-Algorithm
is	O
an	O
integer	O
amount	O
of	O
actual	O
pixels	B-Algorithm
.	O
</s>
<s>
The	O
final	O
"	O
pixel	B-Algorithm
"	O
obtained	O
after	O
these	O
two	O
steps	O
becomes	O
the	O
"	O
anchor	O
"	O
to	O
which	O
all	O
other	O
absolute	O
measurements	O
(	O
e.g.	O
</s>
<s>
Calculate	O
the	O
scaled	O
pixel	B-Algorithm
size	O
as	O
.	O
</s>
<s>
Calculate	O
the	O
real-pixel	O
count	O
per	O
logical-pixel	O
as	O
.	O
</s>
<s>
A	O
browser	O
will	O
then	O
choose	O
to	O
use	O
the	O
1.721	O
×	O
pixel	B-Algorithm
size	O
,	O
or	O
round	O
to	O
a	O
2×	O
ratio	O
.	O
</s>
<s>
A	O
megapixel	O
(	O
MP'''	O
)	O
is	O
a	O
million	O
pixels	B-Algorithm
;	O
the	O
term	O
is	O
used	O
not	O
only	O
for	O
the	O
number	O
of	O
pixels	B-Algorithm
in	O
an	O
image	O
but	O
also	O
to	O
express	O
the	O
number	O
of	O
image	B-Algorithm
sensor	I-Algorithm
elements	O
of	O
digital	B-Device
cameras	I-Device
or	O
the	O
number	O
of	O
display	O
elements	O
of	O
digital	B-Device
displays	I-Device
.	O
</s>
<s>
For	O
example	O
,	O
a	O
camera	O
that	O
makes	O
a	O
2048	O
×	O
1536	O
pixel	B-Algorithm
image	O
(	O
3,145,728	O
finished	O
image	O
pixels	B-Algorithm
)	O
typically	O
uses	O
a	O
few	O
extra	O
rows	O
and	O
columns	O
of	O
sensor	O
elements	O
and	O
is	O
commonly	O
said	O
to	O
have	O
"	O
3.2	O
megapixels	O
"	O
or	O
"	O
3.4	O
megapixels	O
"	O
,	O
depending	O
on	O
whether	O
the	O
number	O
reported	O
is	O
the	O
"	O
effective	O
"	O
or	O
the	O
"	O
total	O
"	O
pixel	B-Algorithm
count	O
.	O
</s>
<s>
Pixel	B-Algorithm
is	O
used	O
to	O
define	O
the	O
resolution	B-Algorithm
of	O
a	O
photo	O
.	O
</s>
<s>
Photo	O
resolution	B-Algorithm
is	O
calculated	O
by	O
multiplying	O
the	O
width	O
and	O
height	O
of	O
a	O
sensor	O
in	O
pixel	B-Algorithm
.	O
</s>
<s>
Digital	B-Device
cameras	I-Device
use	O
photosensitive	O
electronics	O
,	O
either	O
charge-coupled	B-Algorithm
device	I-Algorithm
(	O
CCD	O
)	O
or	O
complementary	B-Device
metal	I-Device
–	I-Device
oxide	I-Device
–	I-Device
semiconductor	I-Device
(	O
CMOS	B-Device
)	O
image	B-Algorithm
sensors	I-Algorithm
,	O
consisting	O
of	O
a	O
large	O
number	O
of	O
single	O
sensor	O
elements	O
,	O
each	O
of	O
which	O
records	O
a	O
measured	O
intensity	O
level	O
.	O
</s>
<s>
In	O
most	O
digital	B-Device
cameras	I-Device
,	O
the	O
sensor	O
array	O
is	O
covered	O
with	O
a	O
patterned	O
color	O
filter	O
mosaic	O
having	O
red	O
,	O
green	O
,	O
and	O
blue	O
regions	O
in	O
the	O
Bayer	B-Algorithm
filter	I-Algorithm
arrangement	O
so	O
that	O
each	O
sensor	O
element	O
can	O
record	O
the	O
intensity	O
of	O
a	O
single	O
primary	O
color	O
of	O
light	O
.	O
</s>
<s>
The	O
camera	O
interpolates	O
the	O
color	O
information	O
of	O
neighboring	O
sensor	O
elements	O
,	O
through	O
a	O
process	O
called	O
demosaicing	B-Algorithm
,	O
to	O
create	O
the	O
final	O
image	O
.	O
</s>
<s>
These	O
sensor	O
elements	O
are	O
often	O
called	O
"	O
pixels	B-Algorithm
"	O
,	O
even	O
though	O
they	O
only	O
record	O
one	O
channel	O
(	O
only	O
red	O
or	O
green	O
or	O
blue	O
)	O
of	O
the	O
final	O
color	B-Algorithm
image	I-Algorithm
.	O
</s>
<s>
Thus	O
,	O
two	O
of	O
the	O
three	O
color	B-Algorithm
channels	I-Algorithm
for	O
each	O
sensor	O
must	O
be	O
interpolated	O
and	O
a	O
so-called	O
N-megapixel	O
''	O
camera	O
that	O
produces	O
an	O
N-megapixel	O
image	O
provides	O
only	O
one-third	O
of	O
the	O
information	O
that	O
an	O
image	O
of	O
the	O
same	O
size	O
could	O
get	O
from	O
a	O
scanner	O
.	O
</s>
<s>
DxO	B-Algorithm
Labs	I-Algorithm
invented	O
the	O
Perceptual	O
MegaPixel	O
(	O
P-MPix	O
)	O
to	O
measure	O
the	O
sharpness	O
that	O
a	O
camera	O
produces	O
when	O
paired	O
to	O
a	O
particular	O
lens	O
–	O
as	O
opposed	O
to	O
the	O
MP	O
a	O
manufacturer	O
states	O
for	O
a	O
camera	O
product	O
,	O
which	O
is	O
based	O
only	O
on	O
the	O
camera	O
's	O
sensor	O
.	O
</s>
<s>
As	O
of	O
mid-2013	O
,	O
the	O
Sigma	B-Algorithm
35	I-Algorithm
mm	I-Algorithm
f/1.4	I-Algorithm
DG	I-Algorithm
HSM	I-Algorithm
lens	I-Algorithm
mounted	O
on	O
a	O
Nikon	B-Algorithm
D800	I-Algorithm
has	O
the	O
highest	O
measured	O
P-MPix	O
.	O
</s>
<s>
In	O
August	O
2019	O
,	O
Xiaomi	O
released	O
the	O
Redmi	O
Note	O
8	O
Pro	O
as	O
the	O
world	O
's	O
first	O
smartphone	B-Application
with	O
64	O
MP	O
camera	O
.	O
</s>
<s>
The	O
sensor	O
is	O
larger	O
than	O
most	O
of	O
bridge	B-Device
camera	I-Device
with	O
1/2.3	O
-inch	O
across	O
sensor	O
.	O
</s>
<s>
One	O
new	O
method	O
to	O
add	O
megapixels	O
has	O
been	O
introduced	O
in	O
a	O
Micro	B-Operating_System
Four	I-Operating_System
Thirds	I-Operating_System
System	I-Operating_System
camera	O
,	O
which	O
only	O
uses	O
a	O
16	O
MP	O
sensor	O
but	O
can	O
produce	O
a	O
64	O
MP	O
RAW	O
(	O
40	O
MP	O
JPEG	O
)	O
image	O
by	O
making	O
two	O
exposures	O
,	O
shifting	O
the	O
sensor	O
by	O
a	O
half	O
pixel	B-Algorithm
between	O
them	O
.	O
</s>
