Save camera frames using OpenCV

Alex123 · 4 Dec 2020, 10:42

Hi,
I'm working on OpenCV using the voxl core-board. I've connected hires + tracking camera.

I want to save the frames of hires camera using cv2.VideoCapture(0) method but it prompts an error.
I'm unable to open the video stream using cv2.VideoCapture(0).

I also want to know the scope of OpenCV using the voxl core-board. (Any limitations?)

Any suggestions would be greatly appreciated!

Thanks!

modaltb · 8 Dec 2020, 00:59

Hi @Alex123 ,

Here's an example that is in development that should similar to what you need:

https://gitlab.com/voxl-public/modal-pipe-architecture/voxl-dfs-server/-/blob/master/clients/voxl-camera-logger.cpp

Alex123 · 11 Dec 2020, 06:45

Hi @modaltb
The above example is in development and it's not that useful. As I'm looking for on-board processing.
Is there any option to access the video feed of Hires camera directly using OpenCV for on-board processing?
(on-board operations like Object Tracking)

Eric Katzfey · 12 Dec 2020, 17:59

There is no direct interface with the hires camera in OpenCV that would allow you to use the VideoCapture API. You will need to get the frames from the camera and feed them to your OpenCV application directly. You could use voxl-rtsp in pipe mode (-m) which would output raw nv21 frames in a named pipe (/dev/frame0). In your application you can read the frames from the pipe (/dev/frame0).

Alex123 · 17 Dec 2020, 08:51

@Eric-Katzfey
Yes! There is no direct interface with the hires camera in OpenCV.
I'll follow the steps as you suggested.

Thanks!