Dalsa Spyder2 S2-2x-04K40, User Manual

Page: 32 / 78

32 Spyder2 4k User’s Manual
03-032-10195-04 DALSA
The white light calibration is performed next to determine the multiplication factors
required to bring each pixel to the required value (balance target) for flat, white output.
Video output is set slightly above the brightest pixel (depending on offset subtracted).
For FPN (dark light) the value of all pixels must be between 1DN and 127DN. For PRNU
(white light) the value must be between 128DN and 254DN. Use the
gl
command to
ensure the proper input to the digital processing, V
input
.
White light calibration will gain up to maximum white light pixel plus the maximum FPN
subtract pixel.
When performing any camera calibration, random noise is minimized by averaging out
up to 64 lines of valid data. To adjust the sample line size, use the
css i
command,
where
i
is 16, 32, 64 (factory setting). A lower value reduces the camera’s calibration time,
at the expense of increased coefficient error.
Calibration time Typical
4096 pixels 38 sec.
LED blinks green while calibrating.
IMPORTANT: While camera is blinking green, do
not power down camera or memory may be corrupted.
Calibration Steps Overview
1. Change camera video mode to calibrated using the command
svm 1
2. Set up the camera operating environment (i.e. line rate, exposure, gain, etc.)
3. Make sure there are suitable calibration targets. The target to calibrate should be a flat
field, e.g. plastic or ceramic for white calibration.
4. Set the calibration sample size using the command
css
(see Returning Multiple Lines
of Video page 26).
5. Perform Dark (FPN) calibration (see Dark Calibration on page 32).
6. Perform White (PRNU) calibration (see White Light Calibration on page 33).
7. Save settings and pixel coefficients using the commands
wus
and
wpc
.
Note: It is important to do the FPN calibration first. Results of the FPN calibration are
used in the PRNU procedure. We recommend that you repeat the calibration when a
temperature change greater than 10 °C occurs.
Dark Calibration
Dark calibration is used to remove the fixed analog offset from the video path. It is
recommended you repeat the calibration when a temperature change greater than 10 °C
occurs.