25
High Dynamic Range (HDR)
8.1.5
Beside the standard linear response the sensor supports a special high dynamic range
mode (HDR) called piecewise linear response. With this mode illuminated pixels that
reach a certain programmable voltage level will be clipped. Darker pixels that do not reach
this threshold remain unchanged. The clipping can be adjusted two times within a single
exposure by configuring the respective time slices and clipping voltage levels. See the
figure below for details.
In this mode, the values for t
Expo0
, t
Expo1
, Pot
0
and
Pot
1
can be edited.
The value for t
Expo2
will be calculated automatically in the camera. (t
Expo2
= t
exposure
- t
Expo0
-
t
Expo1
)
HDR Off
HDR On
Low Illuminati
on
High
Illumination
Pot0
Pot1
Pot2
t
expo0
t
expo1
t
expo2
t
exposure
Sensor Output
Look-Up-Table
8.1.6
The
Look-Up-Table (LUT) can only be used at monochrome cameras. It contains 2
12
(4096) values for the available levels of gray. These values can be adjusted by the user.
Notice
The LUT always calculates with 12 bit input and 12 bit output. In 8/10 bit mode, the lower
bits of the input values are equal zero but can be spread to full 12 bit because of digital
gain. Therefore, all values of the LUT have to be filled in.