Teledyne Falcon4 86M User Manual page 60

PRNU: Customer PRNU_Customer_Target
Target
58  Contents
The following formula is used to calculate
the flatfield corrected pixel:
Monochrome
During operation :
correctedPixelValuex,y =
(sensorPixelValuex,y – DarkRowSubtract-
FFCOffsetx,y –
currentIntTime/CalIntTime*DeltaFPNxy) *
FFCGain[x][y]
* The FPN coefficients must be calculated
with the intended DarkRowSubtractMode
(on or off)
FFCOffsetx,y = the average offset value
per pixel that is measured when the sensor
is dark at the minimum integration time,
with or without the DarkRowSubtract
function enabled.
DeltaFPNxy is average value per pixel
measured at the calibration integration
time –the FPNoffsetxy
FFCGainxy is calculated under
approximately 50% illumination and is the
result of the following calculation
FFCGainxy = Target/(Average signalxy –
DarkRowSubtract- FFCOffsetx,y –
currentIntTime/CalIntTime*DeltaFPNxy)
It is recommended that the target be set
20% higher than the average scene value.
Color
During operation the equation, when
enabled is
correctedPixelValuex,y =
(sensorPixelValuex,y – DarkRowSubtract-
FFCOffsetx,y –
currentIntTime/CalIntTime*DeltaFPNxy) *
FFCGain[x][y]
The dark offsets are calculated as above.
The PRNU coefficient is calculated using
customer entered per color targets. It is
recommended these values be 1.2x the
measured color average.
FFCGainxyr/g/b = Targetr/g/b/(Average
signalxy –
DarkRowSubtract- FFCOffsetx,y –
currentIntTime/CalIntTime*DeltaFPNxy)
White balance gains are set to unity and
saved with the coefficient set.
Falcon4 86M Cameras