ALLIED Vision Technologies Guppy PRO F-503 - Manual (Page 251)

Configuration of the camera
Guppy PRO Technical Manual V4.0.0
249
Loading a look-up table into the camera
Loading a look-up table into the camera is done through the
GPDATA_BUFFER. Because the size of the GPDATA_BUFFER is smaller than a
complete look-up table the data must be written in multiple steps.
To load a lookup table into the camera:
1. Query the limits and ranges by reading LUT_INFO and GPDATA_INFO.
2. Set EnableMemWR to true (1).
3. Set AccessLutNo to the desired number.
4. Set AddrOffset to 0.
5. Write n lookup table data bytes to GPDATA_BUFFER (n might be lower
than the size of the GPDATA_BUFFER; AddrOffset is automatically
adjusted inside the camera).
6. Repeat step 5 until all data is written into the camera.
7. Set EnableMemWR to false (0).
Note

The BitsPerValue field indicates how many bits are read from
the LUT for any grey-value read from the sensor. To determine
the number of bytes occupied for each grey-value round-up
the BitsPerValue field to the next byte boundary.
Examples:
• BitsPerValue = 8  1 byte per grey-value
• BitsPerValue = 14  2 byte per grey-value
Divide MaxLutSize by the number of bytes per grey-value in
order to get the number of LUT entries (grey levels): that is
2
n
with n=number of bits read from sensor.
Note

Guppy PRO cameras have the gamma feature implemented via
a built-in look-up table. Therefore you can not use gamma
and your own look-up table at the same time. Nevertheless
you may combine a gamma look-up table into your own look-
up table.
Note

When using the LUT feature and the gamma feature pay
attention to the following:
• gamma ON  look-up table is switched ON also
• gamma OFF  look-up table is switched OFF also
• look-up table OFF  gamma is switched OFF also
• look-up table ON  gamma is switched OFF