Dalsa Piranha ES Series, User Manual

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Piranha ES-xx User Manual
Teledyne DALSA 03-032-20070-02
55
Calibrating Camera Gain
Pu rp ose: Instead of m anu ally setting the analog gain to a sp ecific valu e, the
cam era can d eterm ine ap p rop riate gain valu es. This com m and
calcu lates and sets the analog gain accord ing to the algorithm
d eterm ined by the first p aram eter.
Syntax:
ccg i t i
Syntax Elem ents:
i
Calibration algorithm to u se.
1
= This algorithm ad ju sts analog gain so that 8% to 13% of
tap ROI p ixels are above the sp ecified target valu e.
2
= This algorithm ad ju sts analog gain so that the average
p ixel valu e in tap ’s ROI is equ al to the sp ecified target valu e.
3
= This algorithm ad ju sts d igital gain so that the average
pixel value in tap’s ROI is equal to the specified target.
4
= This algorithm ad ju sts the analog gain so that the p eak
tap ROI p ixels are ad ju sted to the sp ecified target.
t
Tap valu e. Use
0
for all tap s or
1
to nu m ber of CCD tap s for
ind ivid u al tap selection.
i
Calcu lation target valu e in a range from
1024
to
4055
DN
(12 bit LSB).
N otes:

All d igital settings (d igital offset, FPN and PRN U
coefficients), d igital gain, backgrou nd su btract) shou ld be
tu rned off before calibrating analog gain to avoid
u np red ictable resu lts.

This fu nction requ ires constant light inp u t w hile execu ting.

To u se this com m and , the CCD shift d irection (
scd
) shou ld
be set to forw ard (
0
) or reverse (
1
).

If very few tap p ixels are w ithin the ROI, gain calcu lation
m ay not be op tim al.

When all tap s are selected , tap s ou tsid e of the ROI are set to
the average gain of the tap s that are w ithin the ROI.

Perform analog gain algorithm s before p erform ing FPN and
PRN U calibration.
Exam p le:
ccg 2 0 3040
The follow ing d iagram s su m m arize and p rovid e an exam p le of how analog gain is
calibrated w hen u sing a region of interest.
In the follow ing exam p le, analog gain is being set for a tap insid e the region of interest.
The p eak valu e of the tap is calibrated to the sp ecified target valu e and all other tap s
rem ain u nchanged .