Spyder3 SG-34 GigE Vision Color Manual
47
Teledyne DALSA
03-032-20124-00
204 DN in 8-bit m od e, then the target valu e is (204/ 255) x 4096 = 3277 DN in 8-bit m od e. Therefore,
you can set the target to 3300 DN : Target to Calibrate PRN U is 3300.
4.
Calibrate the PRN U u sing the
PRN U Calibrate
com m and
.
5.
Use the
Read FFC Calibration Result
p aram eter to d eterm ine if you r calibration w as a su ccess or
not.
6.
To save the calibrated PRN U coefficients to the FCC coefficient set show n, u se the
Set PRN U Save
p aram eter.
7.
After the above com m and is com p leted , both the FPN an d PRN U coefficients are au tom atically
tu rned on.
Calibration results from the PRNU Calibrate command:
Su ccess
Clip p ed to m in > Color gain set m iniu m , failu re to reach target
Clip p ed to m ax > Color gain set m axim u m , failu re to reach target
Tim eou t > FPGA d id not retu rn new end of line statistics or vid eo line
W08: Greater than 1% of coefficients have been clip p ed > Greater than 1 % of PRN U coefficients
have been calcu lated to be greater than the m axim u m allow able 8.
Subtracting Background
Use the
Background Subtract
featu res after p erform ing flat field correction if you w ant to im p rove you r
im age in a low contrast scene. It is u sefu l for system s that p rocess 8 bit d ata bu t w ant to take ad vantage of
the camera’s 12 bit d igital p rocessing chain. You shou ld try to m ake your d arkest pixel in the scene equal
to zero.
Background Subtract Selector to select taps and Background Subtract (D N ) to s
u btract a valu e in a
range from
0
to
4095 D N .
Setting Digital System Gain
Im p rove the signal ou tp u t sw ing after a backgrou nd su btract. When su btracting a d igital valu e from the
d igital vid eo signal, u sing the
Background Subtract (D N )
featu re, the ou tp u t can no longer reach its
m axim u m .
Use this com m and to correct for this w here:
Digital Gain (DN) =
max output value
max output value - Background Subtract value
Gain Selector: Tap selection. Digital Gain DN : Gain setting. The gain ranges are
0
to
65535
. The d igital
vid eo valu es are m u ltip lied by this valu e w here:
Digital Gain (DN) =
i
4096
Use this com m and in conju nction w ith the
Background Subtract
com m and .
4k m od el lim ited to 12953 (0 d B effective at factory set analog gain of -10 d B).
