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Look-up table (lut) and gamma function, Description of the data path – ALLIED Vision Technologies Oscar F-810 User Manual

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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

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