GRASS VALLEY XIP-3901, Руководство пользователя

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XIP - 3901
User Manual
slo-mo camera. However, as the native displayed “look” of the SDR BT.709, SDR BT.2020,
BT.2100 HLG, BT.2100 PQ and S-Log3 (SR-Live) production formats are all different (in terms
of color and tone reproduction), color matching of cameras will be difficult using display-
light conversions. Instead, a scene-light conversion should be used.
A scene-light conversion first calculates the light falling on the camera sensor by applying
an inverse OETF, then any color space conversion and highlight expansion, and finally
derives the output signal by applying the output format’s OETF. As the light falling on the
camera sensor is the same regardless of production format, a more exact color and tone
match is obtained than through display-light conversion. An example of a scene-light
conversion for BT.709 to BT.2100 HLG is shown in the Figure below.
Fig. A-4: Scene-light SDR to HDR conversion
Scene-light conversions are also useful for HDR to SDR conversion, where the desire is to
match the “look” of a traditional SDR camera. For example, the LUT 12 (scene-light
conversion from BT.2100 HLG to SDR BT.709) should be used when a BT.2100 HLG
production is required to provide an SDR BT.709 output that closely resembles the “look” of
a traditional SDR BT.709 camera; perhaps for intercutting with SDR BT.709 cameras covering
the same event in SDR.
More details can be found in section 7.1.3 of ITU-R report BT.2408, “Guidance for
Operational Practices in HDR Television Production”.
The table below illustrates the recommended conversions for a range of different signal
types and applications.
Table 2 – Recommended Conversions and LUTs
SDR BT.709
signal
BT.709
Inverse OETF
BT.709
to BT.2020
Colour
SDR BT.709
scene‐light
Gain
Adjustment
for BT.2408
levels
BT.2100
HLG OETF
HDR scene light
HDR BT.2100
HLG signal
SDR BT.2020
scene‐light
Optional
highlight
expansion
BBC LUT
Conversion
Type SDR to HDR
HDR to
SDR
HDR to
HDR
Scene-
Light
Display
-Light
Direct
Mapping
Up-
Mapping
Down-
Mapping
Trans-
code
G
raded
Con
ten
t
SDR graded inserts 5
P

SDR graded programs 3
 
HLG graded content 8
 
PQ graded content 1 or 2
 
Camer
a
to
swit
cher
SDR BT.709 camera 6
 
S-Log3 camera 10
 
"S-Log3 Live" camera 11
 