Pike Technical Manual
V5.2.0
155
Description of the data path
Look-up table (LUT) and gamma function
The Pike camera provides
sixteen (0-15)
user-defined look-up tables (LUT). The
use of one LUT allows any function (in the form Output = F(Input)) to be stored
in the camera's RAM and to be applied on the individual pixels of an image at
run-time.
The address lines of the RAM are connected to the incoming digital data, these
in turn point to the values of functions which are calculated offline, e.g. with a
spreadsheet program.
This function needs to be loaded into the camera's RAM before use.
One example of using an LUT is the gamma LUT:
There are two gamma LUTs (gamma=0.7 and gamma=0.45)
Output = (Input)
0.7
and Output = (Input)
0.45
These two gamma LUTs are used with all Pike models.
Gamma is known as compensation for the nonlinear brightness response of
many displays e.g. CRT monitors. The look-up table converts the incoming
14 bit
from the digitizer to outgoing up to
14 bit
.
Figure 81: LUTs with gamma=0.45, gamma=0.7
8000
10000
12000
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16000
O
u
tput
Output = f (Input)
Pike, gamma=0.45
Pike, gamma=0.7
0
2000
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6000
0
2000
4000
6000
8000
10000
12000
14000
16000
Input
