» VL.OpenCV Camera Calibration Helper
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VL.OpenCV Camera Calibration Helper

Credits: ravazquez and Marshmallow Laser Feast for sponsoring the development of this tool.


This tool is meant to aid you in the process of generating a camera calibration file using OpenCV's xml format. The produced file contains Intrinsics information, specifically the camera matrix and the distortion coefficients.

You can later recover this data using the IntrinsicsReader (Calibration) VL.OpenCV node.

You will need to use a calibration pattern, if you don't have one a there is a link in the patch where you can get one.

You must match your calibration pattern's columns and rows based on the INNER OUTMOUST corners in your pattern. The pattern linked in the patch is 9x6.

You must also measure and specify your pattern's square side length in the patch (in meters).

To be used with vvvv gamma 2020.2.2 and above.

Press 'H' while the Renderer is in focus to display additional shortcuts (britghtness, contrast, reset).

The recommendation is to try and cover as much of the edges of your sensor's field of view as possible, and to try and rotate the pattern in all three axes between the different samples.

Getting samples at different distances is also recommended.


18.11.20 [16:35 UTC] by ravazquez | 470 downloads
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Older Revisions

28.10.20 [23:36 UTC] by ravazquez | 184 downloads

ravazquez 18/11/2020 - 17:37

New version up, the old one was somewhat broken.

Fixed a couple of bugs that were associated with Azure Kinect specific scenarios.

Added VideoIn to make things easier.


ggml 03/03/2021 - 00:31

would the calibration data apply to undistort ex9 ?
is there a dx11 version of undistort available ?

ravazquez 08/03/2021 - 19:18

I have not tested it but I doubt it @ggml.

The data itself is stored in an XML file so you could potentially copy it into whatever format ex9 expects by hand, I presume the existing ex9 Undistort is also using opencv under the hood (a much older version most likely) but the principles remain the same.

Best of luck to you!

u7angel 12/03/2021 - 12:35

@ggml, try this and let me know if this works for you

ggml 13/03/2021 - 01:09

hi, u7angel
the shader seems to be missing undistort.fxh

anonymous user login


~28d ago

manuel: very cool to generate matcap / cubemap for reflections https://cables.gl/p/pDCOCw

~29d ago

joreg: Join us for the 19th #vvvv meetup on November 11th: https://thenodeinstitute.org/event/19-worldwide-vvvv-meetup/

~1mth ago

~2mth ago

joreg: @zaid please ask this in the forum: https://discourse.vvvv.org/

~2mth ago

zaid: how can i detect a changing spread in gamma? the old workflow with a change and select node isnt possible. cheers

~2mth ago

joreg: @dawoof such a question is probably better asked in the forum or chat

~2mth ago

dawoof: hey vvvvers, What are yall's fav depth-camera for body tracking? (dancing in this case) eyeing the ZED but the delivery time is long