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Piranha4 2K and 4K Camera Color User's Manual
03-032-20180-05
Teledyne DALSA
Parallax correction
When the cam era it is not p erp end icu lar to the object su rface the P4 color cam era w ill exhibit color. The
p arallax d istortion increases w hen im agin g at steep angles relative to the cam eras im aging p lain. This is
an op tical effect cau sed by the line sp acing of the three ind ivid u al colors. This sp acing resu lts in a
d ifferent m agnification for each line at high angles. As show n in the figu re below , there is color d istortion
at the extrem es end s of the im age bu t at the centre of the im age the color d istortion d oes not show u p .
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Figure 11: Image with Horizontal Color Alignment Issues
Using the P4 color cam eras Parallax Correction featu re, the op tical m agnification for each line is ad ju sted
su ch that colors can be lined u p at the extrem e end s of the im age w ithou t affecting the center. Using the
featu re Im age Distortion Correction Mod e (shm = 1) this fea tu re can be tu rned on. Using the featu re
Im age Distortion Correction Line Selector the u ser can select red and green to correct the d istortion. N ote.
The red and green lines are ad ju sted to to align w ith the center blu e line. Im age Distortion Parallax
Correction Pixel Stretch (sha - Set horizontal alignm ent in float f<valu e 0-3>) is u sed to ad d the am ou nt
of correction need ed to the im age. The valu e entered here m u st be betw een 0 and 3 (d ecim al valu es are
accep ted .
Figure 12: CamExpert Parallax Correction Controls
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Figure 13: Figure 14 Corrected Image
The figu re above is the sam e im age corrected u sing the p arallax correction. In this exam p le the v alu e of 3
w as u sed to correct the im age.
