Piranha4 2K and 4K Color Camera User's Manual
17
Teledyne DALSA
03-032-20180-05
Figure 10: 2K Quadlinear Sensor Line Spacing Diagram
In the case of the 4k cam eras, the three lines of p ixels are sep arated by tw o lines of sp acing and this line
sp acing is equ al to 2x the sensor p ixel size. In the case of the 2k cam eras, only a single line of sp ace
sep arates the colored lines—w ith the excep tion of the m onochrom e line, w h ich has three lines of sp acing.
When the im age p asses the three lines of p ixels, the red , blu e and green com p onents for the sam e im age
location are cap tu red at a d ifferent tim e as d ictated by the line sp acing. The cam era au tom atically corrects
for the line sp acing to ensu re that the red , blu e and green com p onents of the im age p ixel are all aligned
w hen ou tp u t. H ow ever, this is only correct w hen the object p ixel size is squ are ; i.e., the d istance m oved
by the object for one EXSYN C p eriod is equ al to the w id th of the object p ixel. In som e ap p lications it m ay
not be p ossible to achieve a ‘squ are’ object p ixel as fine ad ju stm ent of the lens m agnification and / or the
d istance m oved for each EXSYN C p eriod is not p ossible. This scenario m ay be esp ecially ap p arent w hen
trying to integrate the cam era into an existing system .
When it is not p ossible to generate a squ are object p ixel, color artefacts w ill occu r in the scan d irection
and is p articu larly noticeable at sharp ed ge transitions. The size of the ed ge artefa ct is p rop ortional to
how far the p ixel is from squ are. To correct for this, the cam era has a featu re, Line Sp atial Correction (or
three letter com m and ssa), w hich allow s fine ad ju stm ent of the com p ensation m echanism the cam era u ses
to correct for the line sp acing.
The d efau lt setting for this featu re is 3 (4k m od el) or 2 (2k m od el), w hich is set for squ are object p ixels.
The setting can be ad ju sted from 0 to 5 to com p ensate for rectangu lar p ixels
—
w hether they are too long
or to short.
The follow ing exam p les of im age artefacts show black to w hite im age transitions and the associated
corrected im age after ap p lying a sp ecific ssa setting.
14.08um
14.08um
Red
Blue
Green
14.08um
14.08um
14.08um
Mono
14.08um
42.24um
