® 16k/8k CXP Color
33
e2v semiconductors SAS 2014
PRNU Calibration
The User must propose a white/gray uniform target to the Camera (not a fixed paper).
The Gain/Light conditions must give a non saturated image in any Line.
The Camera must be set in the final conditions of Light/ Gain and in the final position in the System.
I f required, set a user target for the FFC adjust and enable it.
White uniform (moving) target
Launch the FFC
Enable the FFC
You can save the FFC result (both FPN+PRNU in the same time) in one of the 4 x FFC User Banks.
The user target and Gain are saved with the associated FFC in the same memory.
Advices
The Cameras have 4 x FFC Banks to save 4 x different FFC calibrations. You can use this feature if your system
needs some different conditions of lightning and/or Gain because of the inspection of different objects : You can
perform one FFC per condition of Gain/setting of the Camera ( 4 Max) and recall one of the four global settings
(Camera Configu FFC + Line Balance) when required.
Feature
Description
FFCEnable
- Disable Flat Field Correction
- Enable Flat Field Correction
FPNReset
Reset FPN coefficients of the RAM memory
PRNUReset
Reset PRNU coefficients of the RAM memory
FPNValueAll
Memory containing FPN coefficients
Format: S9.1 => -256 to +255.5 by step of ½
FPNValueSize
Integer providing FPN value size in byte
PRNUValueAll
Memory containing PRNU
Value from 0 to 4095
Format: U2.10 : (1+coeff/1024) => x1 to x4.999877 by step of 1/1024
PRNUValueSize
Integer providing PRNU value size in byte
FFCCalibrationCtrl
FFC calibration
0 = Abort PRNU calibration by setting it to “Off” (no effect if already stopped)
1 = Launch PRNU calibration by setting it to “Once” (no effect if already launched)
FPNCalibrationCtrl
FPN calibration
0 = Abort FPN calibration by setting it to “Off” (no effect if already stopped)
1 = Launch FPN calibration by setting it to “Once” (no effect if already launched)
6.2.7.1
Automatic Calibration
Some Warnings can be issued from the PRNU/FPN Calibration Process as “pixel Overflow” of “Pixel Underflow”
because some pixels have been detected as too high or too low in the source image to be corrected efficiently.
The Calculation result will be proposed anyway as it’s just a warning message.
The Status Register is the changed and displayed in Device Control Status section.
6.2.7.2
Manual Flat Field Correction
The FFC Coefficients can also be processed outside of the Camera or changed manually by accessing directly their values
in the Camera : This is the “Manual” FFC.
