<s>
ITU-R	B-Device
Recommendation	I-Device
BT.2100	I-Device
,	O
more	O
commonly	O
known	O
by	O
the	O
abbreviations	O
Rec	O
.	O
</s>
<s>
2100	O
or	O
BT.2100	B-Device
,	O
introduced	O
high-dynamic-range	B-Application
television	I-Application
(	O
HDR-TV	B-Application
)	O
by	O
recommending	O
the	O
use	O
of	O
the	O
perceptual	B-Algorithm
quantizer	I-Algorithm
(	O
PQ	B-Algorithm
)	O
or	O
hybrid	O
log	O
–	O
gamma	O
(	O
HLG	O
)	O
transfer	B-Algorithm
functions	I-Algorithm
instead	O
of	O
the	O
traditional	O
"	O
gamma	O
"	O
previously	O
used	O
for	O
SDR-TV	O
.	O
</s>
<s>
It	O
defines	O
various	O
aspects	O
of	O
HDR-TV	B-Application
such	O
as	O
display	B-General_Concept
resolution	I-General_Concept
(	O
HDTV	B-Device
and	O
UHDTV	B-Device
)	O
,	O
frame	O
rate	O
,	O
chroma	O
subsampling	O
,	O
bit	O
depth	O
,	O
color	B-Algorithm
space	I-Algorithm
,	O
color	O
primaries	O
,	O
white	O
point	O
,	O
and	O
transfer	B-Algorithm
function	I-Algorithm
.	O
</s>
<s>
Rec.2100	B-Device
defines	O
two	O
sets	O
of	O
HDR	B-Application
transfer	B-Algorithm
functions	I-Algorithm
which	O
are	O
perceptual	B-Algorithm
quantization	I-Algorithm
(	O
PQ	B-Algorithm
)	O
and	O
hybrid	O
log-gamma	O
(	O
HLG	O
)	O
.	O
</s>
<s>
Within	O
each	O
set	O
,	O
the	O
documented	O
transfer	B-Algorithm
functions	I-Algorithm
include	O
an	O
:	O
</s>
<s>
Rec.2100	B-Device
use	O
the	O
same	O
color	O
primaries	O
as	O
Rec	O
.	O
</s>
<s>
Rec.2100	B-Device
specifies	O
three	O
resolutions	O
of	O
1920	O
×	O
1080	O
(	O
"	O
Full	O
HD	O
"	O
)	O
,	O
3840	O
×	O
2160	O
(	O
"	O
4K	B-Device
UHD	O
"	O
)	O
,	O
and	O
7680	O
×	O
4320	O
(	O
"	O
8K	O
UHD	O
"	O
)	O
.	O
</s>
<s>
These	O
resolutions	O
have	O
an	O
aspect	O
ratio	O
of	O
16:9	O
and	O
use	O
square	O
pixels	B-Algorithm
.	O
</s>
<s>
Rec.2100	B-Device
specifies	O
the	O
following	O
frame	O
rates	O
:	O
120p	O
,	O
119.88p	O
,	O
100p	O
,	O
60p	O
,	O
59.94p	O
,	O
50p	O
,	O
30p	O
,	O
29.97p	O
,	O
25p	O
,	O
24p	O
,	O
23.976p	O
.	O
</s>
<s>
Only	O
progressive	B-Device
scan	I-Device
frame	O
rates	O
are	O
allowed	O
.	O
</s>
<s>
Rec.2100	B-Device
specifies	O
a	O
bit	O
depth	O
of	O
either	O
10-bits	O
per	O
sample	O
or	O
12-bits	O
per	O
sample	O
,	O
with	O
either	O
narrow	O
range	O
or	O
full	O
range	O
color	O
values	O
.	O
</s>
<s>
Rec.2100	B-Device
specifies	O
the	O
use	O
of	O
RGB	O
,	O
YCbCr	O
,	O
and	O
ICtCp	B-Device
.	O
</s>
<s>
ICtCp	B-Device
provides	O
an	O
improved	O
color	O
representation	O
that	O
is	O
designed	O
for	O
high	B-Application
dynamic	I-Application
range	I-Application
(	O
HDR	B-Application
)	O
and	O
wide	O
color	O
gamut	O
signals	O
(	O
WCG	O
)	O
.	O
</s>
<s>
Rec.2100	B-Device
allows	O
for	O
RGB	O
,	O
YCbCr	O
,	O
and	O
ICtCp	B-Device
signal	O
formats	O
with	O
4:4:4	O
,	O
4:2:2	O
,	O
and	O
4:2:0	O
chroma	O
subsampling	O
.	O
</s>
<s>
Rec.2100	B-Device
specifies	O
that	O
if	O
a	O
luma	O
(	O
Y	O
 '	O
)	O
signal	O
is	O
made	O
that	O
it	O
use	O
the	O
same	O
matrix	O
coefficients	O
as	O
Rec	O
.	O
</s>
<s>
But	O
in	O
H.265	O
(	O
2018-02	O
)	O
top-left	O
chroma	O
siting	O
was	O
mandated	O
for	O
BT.2020-2	O
and	O
BT.2100-1	O
,	O
that	O
must	O
be	O
described	O
in	O
VUI	O
(	O
video	O
usability	O
information	O
)	O
as	O
such	O
.	O
</s>
<s>
Blu-ray	O
also	O
uses	O
top-left	O
chroma	O
for	O
HDR	B-Application
,	O
including	O
for	O
Dolby	O
Vision	O
.	O
</s>
