How to get information about the parent of an object


I’ve been developing a 2 stage lincence-plate-recognizer on deepstream, by modifying deepstream-test2 application.

I’m trying to get the number plate characters in order from left to right.
I was able to do this if there is only one plate detected in the frame.

However, I’m not sure how to approach the problem of getting the different characters, based on what their parent is.

Is there a parent id that i can get from each child, and then add them to different arrays based on their parent. Is the parent id a simple int or char, or is it guint?

If you could give me some sort of direction or example as to how to aproach this, I would appreciate it.

Kind regards.

You can get frame_num in frame metadata which the objects belong to.

This is metadata doc:

And check metadata usage in the samples.

This doesn’t really help me as i’ve already read the documentation and seen multiple examples, but there is nothing about linking child objects to their parent to form groups of child objects based on their parent.

Also, in the link you have provided in the picture, in NvDsObjectMeta there is a field sub_object_list, that does not exists in the NVIDIA DeepStream SDK API Reference.

Please give some more useful information as to how to approach my problem.

You can refer to back to back detector application which demonstrates relationship between parent and child objects