Description of the data path
STINGRAY Technical Manual
V2.2.0
116
Look-up table (LUT) and gamma function
The AVT Stingray 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 an LUT is the gamma LUT:
There is one gamma LUT (gamma=0.45)
Output = (Input)
0.45
This gamma LUT is used with all Stingray 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
12 bit
from the digitizer to outgoing
10 bit
.
Figure 62: LUT with gamma=0.45
Output = f (Input)
0
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800
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0
500
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Input
O
u
tput
Stingray, gamma=0.45
