Description of the data path
OSCAR Technical Manual
V2.4.0
71
Look-up table (LUT) and gamma function
The AVT Oscar camera provides one user-defined look-up table (LUT). The use
of this 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 a LUT is the gamma LUT:
Output = (Input)
0.5
This gamma LUT is used with all Oscar models.
It is known as compensation for the nonlinear brightness response of many
displays e.g. CRT monitors. The look-up table converts the incoming
12 bit
from the digitizer to outgoing
8 bit
.
Figure 30: Gamma LUT
Output = (Input)
gamma
0
50
100
150
200
250
0
500
1000
1500
2000
2500
3000
3500
4000
Input
Ou
tp
u
t
Oscar, gamma=0.5