® 16k CL
28
UM 16kCL – REVC – 11/14
e2v semiconductors SAS 2014
6.3.5.2
Automatic Calibration
FFC Low Band Filter (
FFCAutoTargetLevel
)
:
set the value for the User Target.
Read function : “r lffw”. Returns the Filter Interval size (from 0 to 255)
Write function : “w lffw <value>” : Set the Interval size for the filter (0 / 1 … 255)
0 : Disables the FFC Low Band Filter
1 to 255 : Set the interval size (+/- the value around the pixel) for the Low Band filter
When you can’t provide a moving Target to the Camera during the PRNU Calibration you can setup the FFC Low Band
Filter in order to remove the defect from the Target before calculating the FFC parameters. The Value set in the FFC
filter defined the size of the interval around each pixel : The Filter will replace each pixel value by the average on the
interval.
FPN/DSNU Calibration
:
o
FPN Calibration Control (
FPNCalibrationCtrl
) : Launch or abort of the FPN process for the Offsets calculation.
These commands are available in the CommCam “Flat Field Correction / Automatic Calibration ” section :
Read function : “r calo” : Returns the FPN Calculation Process Status (0 if finished, 1 if processing)
Write function :
“w calo 1” : Launch the FPN Calibration Process.
“w calo 0” : Abort the FPN Calibration Process.
o
FPN Coefficient Reset (
FPNReset
) : Reset the FPN (Offsets) coefficient in Memory. This command is available in
the CommCam “Flat Field Correction / Manual Calibration ” section :
Write function : “w rsto 0” : Reset (set to 0) the FPN coefficients in memory. This doesn’t affect the FFC User
Memory Bank but only the active coefficients in Memory.
PRNU Calibration
:
o
PRNU Calibration Control
(
FFCCalibrationCtrl
) : Launch or abort of the PRNU process for the Gains calculation.
This command is available in the CommCam “Flat Field Correction / Automatic Calibration ” section :
Read function : “r calg” : Returns the PRNU Calculation Process Status (0 if finished, 1 if processing)
Write function :
“w calg 1” : Launch the PRNU Calibration Process.
“w calg 0” : Abort the PRNU Calibration Process.
o
PRNU coefficient Reset (
PRNUReset
) : Reset the PRNU (Gains) coefficient in Memory. This command is available
in the CommCam “Flat Field Correction / Manual Calibration ” section :
Write function : “w rstg 0” : Reset (set to “x1”) the PRNU coefficients in memory. This doesn’t affect the FFC
User Memory Bank but only the active coefficients in Memory.
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 CommCam “Status” section :
Register status is detailed chap §6.3.1.