Instruction manual

Description of the data path
8.8 Lookup table (LUT) and Gamma function
apply it on
e individual pixels of an image at run-time.
adsheet program.
ar brightness response of many displays
er to 8 bits.
The AVT Marlin camera provides one user-defined lookup table (LUT). The use of this LUT allows
any function (in the form Output = F(Input)T to be stored in the camera’s RAM and to
th
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 spre
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 is used with all CCD
odels. This is known as compensation for the nonlinem
e.g. CRT monitors. The lookup table converts the 10 bits from the digitiz
32
128
160
192
224
96
64
0
0 128 256 384 512 640 768 896
Figure 35: Gamma LUT
 The input value is the 10-bit value from the digitizer. The gamma LUT of the CCD models
ts the most significant 8 Bit as shown above.
n gamma correction is enabled.
outpu
 As gamma correction for the CCD models is also implemented via the lookup table, it is not
possible to use a different LUT whe
MARLIN Technical Manua
l
Page 67