72 Piranha4 2K and 4K Camera Color User's Manual03-032-20180-06 Teledyne DALSACalibrating the CameraImportant 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 33: Flat Field Calibration in CamExpertOverviewThe following diagram and accompanying description explain the cameras signal processing chain. Eachelement shown, with the exception of color interpolation, is user programmable.Figure 34: Camera Calibration Process.Digital Processing1. Fixed pattern noise (FPN) calibration is used to subtract any residual dark level that may occur inthe application.2. Photo response non uniformity (PRNU) calibration is used to correct for variations in theillumination intensity and / or lens vignetting. When performed, this calibration will cause theVideoGainOutputVideoDigital Processing (color)-+OffsetBlackLevel(ssb)xGain(ssg 3)-Calibrate FPNflatfieldCalibrationFPN(ccf)xRxG xBWhiteBalancingBalanceWhiteAuto(bwa,ssg(0,1,2))X X X XX X X XX X X XColorCorrectioncolorCorrectionMode(ctv)xCalibratePRNUflatfieldCorrectionModeflatfieldCalibrationPRNUflatfieldCorrectionAlgorithm(cpa,ffm)
