Marlin F-131 With Three Knee-Points - Allied Vision Technologies AVT Marlin Technical Manual

Description of the data path
Register Name
0xF1000280 HDR_CONTROL
0xF1000284 KNEEPOINT_1
0xF1000288 KNEEPOINT_2
0xF100028C KNEEPOINT_3
This dual slope reset pulse resets the analogue signal of the pixels below the
dual slope reset level to this level. After the reset, the analogue signal starts
to decrease with the same slope as before (pink P3 and yellow P4 lines).
This introduces a knee-point in the exposure function.
If the dual slope reset pulse is placed at the end of the integration time (90%
for instance), the analogue signal which would have normally reached the
saturation level is no longer saturated at read out. This effect increases the
optical dynamic range of the sensor.
It is important to notice that pixel signals above the dual slope reset level
will be left unaffected (green P1 and green P2).

MARLIN F-131 with three knee-points

The MARLIN F-131 offers up to three knee-points when in global shutter
mode. This functionality is controlled via the following registers.
Field
Presence_Inq
---
ON_OFF
---
MaxKneePoints
---
KneePoints
---
Kneepoint1
---
Kneepoint2
---
Kneepoint3
Table 27: High dynamic range configuration register
Note It is recommended that knee-points be adjusted to 10 %, 5 %
and 2.5 % of the total exposure or shutter time being applied
at the end of the exposure.
Bit Description
[0] Indicates presence of this
feature (read only)
[1..5] Reserved
[6] Enable/disable HDR mode
[7..19] Reserved
[20..23] R: Number of knee-points
possible in this mode
[24..27] Reserved
[28..31] W: Number of active knee-
points
[0..15] Reserved
[16..31] R/W: Time in µs
[0..15] Reserved
[16..31] R/W: Time in µs
[0..15] Reserved
[16..31] R/W: Time in µs
MARLIN Technical Manual V2.4.0
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