ZED Calibration - Multiple distortion coefficients - What are these?

Software Python
,
1

Hi,

I am not sure to understand what the different distortion coefficients present in the factory calibration represents and how do they get updated.

The configuration file presents both per camera, per resolution distortion values

[LEFT_CAM_2K]
ā€¦
k1=-0.0620869
k2=0.0404839
p1=-0.000180545
p2=0.00043134
k3=-0.0164286

and per camera distortion values:

[LEFT_DISTO]
k1=-1.54086
k2=3.71464
k3=-0.0835021
k4=-1.45078
k5=3.57006
k6=0.107865
p1=-0.000324935
p2=0.000233897

  • What is the difference between?
  • How are they both used?
  • Do they both get potentially updated by the camera online self calibration?

Best

2

Hi,
Per resolution distortion is a legacy behavior, for SDK version < 3.5.
The distortion is the same for every resolution so a new field was added, if it is available it overwrites per resolution distortion. It is an extend (more coefficient) of the per resolution distortion.
If you want more information about them you can take a look at this documentation:
https://docs.opencv.org/4.x/d9/d0c/group__calib3d.html#ga7dfb72c9cf9780a347fbe3d1c47e5d5a
we follow the same convention.
Our self calibration does not update the distortion.

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