Dalsa Piranha 3 P3-80-08k40-00-R, Руководство пользователя

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Piranha 3 User Manual
03-032-10216-06 Teledyne DALSA
46
Performing PRNU to a User Entered Value
Pu rp ose: Perform s PRN U calibration to u ser entered valu e and elim inates the
d ifference in resp onsivity betw een the m ost and least sensitive p ixel
creating a u niform resp onse to light. Using this com m and , you m u st
p rovid e a calibration target.
Syntax:
cpa i i
Syntax Elem ents:
i
PRN U calibration algorithm to u se:
1
= This algorithm first ad ju sts each tap ’s analog gain so that 8-
13% of p ixels w ithin a tap are above the valu e sp ecified in the
target valu e p aram eter. PRN U calibration then occu rs u sing the
p eak p ixel in the region of interest (ROI).
2
= Calcu lates the PRN U coefficients u sing the entered target
valu e as show n below :
PRNU Coefficient =
Target
(AVG Pixel Value ) - (FPN + value)
sdo
i i
i
The calcu lation is p erform ed for all sensor p ixels bu t w arnings
are only ap p lied to p ixels in the region of interest. This
algorithm is u sefu l for achieving u niform ou tp u t across m u ltip le
cam eras. Recom m end ed p eak vid eo ou tp u t before PRN U
calibration is 5-20% low er than target. The target valu e m u st be
greater than the cu rrent p eak ou tp u t valu e.
This com m and p erform s the sam e fu nction as the
cpp
com m and bu t requ ires that you enter a target valu e.
3
= This algorithm inclu d es an analog gain ad ju stm ent p rior to
PRN U calibration. Analog gain is first ad ju sted so that the p eak
pixel value in tap’s ROI is w ithin 97 to 99% of the specified
target valu e. It then calcu lates the PRN U coefficients u sing the
target valu e as show n below :
PRNU Coefficient =
Target
(AVG Pixel Value ) - (FPN + value)
sdo
i i
i
The calcu lation is p erform ed for all sensor p ixels bu t w arnings
are only ap p lied to p ixels in the region of interest. This
algorithm is u sefu l for achieving u niform ou tp u t across m u ltip le
cam eras.
4 = Calcu lates the PRN U coefficient in the sam e w ay as cpa 2
w ith the excep tion that this com m and only calcu lates PRN U for
p ixels w ithin the cu rrent Region of Interest (ROI).
i
Peak target valu e in a range from 1024 to 40554DN .
N otes:

Perform all analog ad ju stm ents before calibrating PRN U.

Calibrate FPN before calibrating PRN U. If FPN cannot be
calibrated , u se the
rpc
com m and to reset all coefficients to
zero, and save them to m em ory w ith the
wfc
com m and . You
can then ad ju st the d igital offset (
sdo
com m and ) to rem ove
som e of the FPN .

N ote: Refer to Calibrating the Cam era to Rem ove N on -
Uniform ity (Flat Field Correction)on p age 35 for a p roced u ral
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