User`s manual

Piranha4 2K and 4K Color Camera User's Manual 67
Teledyne DALSA 03-032-20180-02
Calibrating the Camera
Important Note: to ensure best results, the conditions under which you calibrate the camera (e.g.
temperature and illumination) should be as close to the actual operating conditions as possible.
Figure 31: Flat Field Calibration in CamExpert
Overview
The following diagram and accompanying description explain the cameras signal processing chain. Each
element shown, with the exception of color interpolation, is user programmable.
Figure 32: Camera Calibration Process.
Digital Processing
1. Fixed pattern noise (FPN) calibration is used to subtract any residual dark level that may occur in
the application.
2. Photo response non uniformity (PRNU) calibration is used to correct for variations in the
illumination intensity and / or lens vignetting. When performed, this calibration will cause the
Video
Gain
Output
Video
Digital Processing (color)
-
+
Offset
BlackLevel
(ssb)
x
Gain
(ssg 3)
-
Calibrate FPN
flatfieldCalibrationFPN
(ccf)
xR
xG xB
White
Balancing
BalanceWhiteAuto
(bwa,
ssg(0,1,2))
X X X X
X X X X
X X X X
Color
Correction
colorCorrectionMode
(ctv)
x
Calibrate
PRNU
flatfieldCorrectionMode
flatfieldCalibrationPRNU
flatfieldCorrectionAlgorithm
(cpa,ffm)