SVO Calibration at posteriori

I’ve a doubt about the use of optional_opencv_calibration_file.

Is it working also with SVO? I mean, if I recorded an SVO file and then I want to use different calibration parameters at posteriori is it possible using optional_opencv_calibration_file? Or it will work only for a new record?
I’m calling get_camera_information() after used the above mentioned setup and it returns me different calibration parameters. Maybe is it about the autocalibration? Do the autocalibration runs and I need to specified in another field?

Thank you.

Hi @umbnich
yes, it works also for SVOs.
The self-calibration is active also for SVOs if you do not disable it.

So, to make my optional_opencv_calibration_file to work I need to disable the self-calibration?

Not exactly, self-calibration, as explained in the documentation, is a refinement.
You must disable it if you want to use your exact calibration file without refinements.

Can I ask you why you want to use your calibration file?
The ZED factory calibration is an automated precise process and a manual calibration cannot reach the same results in precision.
A manual calibration is usually required if the camera is totally misaligned because it received a strong shock or if you are adding some kind of lens distortion in front of it (custom lenses, glass case, underwater applications, ecc).

Yes, is this the case. I am integrating the camera in an underwater enclosure so I need to re-calibrate it.
The use case is:

  • Record the calibration pattern in underwater;
  • Start the mission in underwater;
  • Calibrate offline in office;
  • Process the data acquired with the offline calibration at posteriori
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In that case, I suggest disabling the self-calibration too :+1:

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Thanks a lot!

Il giorno gio 24 nov 2022 alle ore 09:58 Walter Lucetti (Stereolabs) ha scritto:

Just to be more precise:

If I disable the auto-calibration and then I get the calibration params, I will get the actual calibration parameters I specified in my custom calibration file or the ones at the time of the acquisition?

Thank you

You obtain the parameters loaded from the configuration file.

Please note that the “rectified” images have different parameters because they are recalculated after the remapping procedure, the parameter of the configuration file are related to the raw images.