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Reference Manual ATOM one SSM500
13 Look-up Table Management
The lookup table has a bit depth of 16 Bit (both input and output values). There are four
ways to setup the lookup table:
1. The LUTs are fully programmable with 24 sample points. All intermediate values are
calculated with a spline interpolator.
2. The LUTs can be programmed by specifying a set of parameters which will be used
to calculate a gamma curve like it is specified in the REC.709 standard. This will
then automatically compute the 24 sample points needed for method 1 and start the
spline interpolator.
3. The LUTs can be fast configured by specifying only the desired gamma value of the
REC.709 gamma function.
4. The LUTs can be configured with a fixed configuration of three presets which
include the default REC.709 gamma curve and two HDR gamma curves: PQ and
HLG.
Method 1 and 2 are intended for offline calibration of the camera. Method 3 is intended for
usage during device operation. Method 4 can be used if the gamma table is not changed
during production.
For method 1 and 2 the user can store 5 independent presets with 24 sample points each.
The default is the standard REC.709 curve, but the presets can be changed by the user.
For method 3 and 4 presets are not available.
Both SDI outputs of each chain (live and playback) use the same lookup table, but you can
have different lookup tables for the live and playback chain.
The LUT's can be configured for each color component separately (Red, Green, Blue)
when using method 1. Method 2 and 3 will setup all components identically.
13.1.1
How to setup a lookup table using interpolation
When using interpolation switch to lut mode 0:
lut_mode 0
Method 1:
For
manual LUT
setup the following steps are required.
1. Select Chain to configure:
out 1
for Live,
out 2
for Playback Chain
2. Disable LUT:
lut_enable 0 0
3. Select preset storage:
lut_preset 0
4. Clear current LUT configuration:
lut_reset
5. Add your sample points:
lut_sample 100 200 200 400 500 2000 <...>
6. Calculate LUT curve:
lut_interpolate
7. Enable LUT again:
lut_enable 0 1
Method 2:
For
functional LUT
setup the following steps are required.
The functional LUT will calculate sample points based on a function.
