30 Spyder2 User’s Manual
03-032-10091-06 Teledyne DALSA
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,
w here
i is 16, 32, 64 (factory setti ng). A low er value reduces the camera’s calibration time,
at the expense of i ncreased coeffici ent er r or.
Calibration time Typical
512 6 sec.
1024 10 sec.
2048 19 sec.
LED blinks green while calibrating.
Default User Calibration Coefficients
In order to mini mi ze the pixel PRNU when used in calibrated mode, a gener i c fl at-field
calibration is performed on each camera at the factory. The calibration coefficients are
then saved as user setti ngs in the camera and are avai lable for future use.
Factory flat-field calibration is performed at gain setting 5 in calibrated mode.
At the completion of the factory calibration and camera testing, the PRN U and FPN
coefficients are written to the camera, the calibrated mode gain is set to 0, and the video
mode is set to uncalibrated. These set t i ngs are saved as user set ti ngs.
WARNING: Performing a calibration and writing the FPN and PRNU pixel coefficients
to the camera will overwrite the factory generated calibration coeff i cients.
In order to use the factory generated flat-field coefficients optimally, it will be necessary
to put the camera into calibrated mode and then change the gain setting to 5. This action
w i l l cause the follow i ng m essage to be generated by the camera:
I N FO: Changing analog settings of calibration mode voids pixel calibration
Thi s i s an autom ati c message that is generated by the camera w henever a change is made
to an analog setting whi l e the camera is in calibrated mode. The pixel coeffi ci ents are not
changed in any manner and the calibration will be applied normally.
The pixel coefficients are applied when in calibrated mode at any setting of gain and the
result is improved PRNU and FPN performance when compared to using the camera in
an uncalibrated mode.
From the factory, the optimum calibrated performance is achieved with a gain setting of
5.
The user may change the calibrated gain setting to any value and then save as user
settings. If the camera is to be used at a gain setting other than 5, then it is recomm ended
that a cal i bration be perfor med once the desired camera setti ngs hav e been determi ned.
Calibration Steps Overview
1. Change the camera’s video mode to calibrated setting, using the command svm 1.
2. Set up the camera oper ating env i ronment (i .e. l ine rate, exposure, gain, etc.).
3. M ake sure that there are suitable calibration targets. The target to calibrate should be a
flat field, e.g. uniform plastic or ceramic for white calibration.
4. Set the calibration sample size, using the command
css (see Returning Multiple
Lines of Video page 25).
To Next Page
Loading...
