How to access tracker id of objects that crossed the line zone/ objects that are inside polygon zone

[abichoi]

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Question

Is it possible to access the tracker id of objects that crossed the line zone or the id of objects that are inside the polygon zone?

Additional

No response

[rolson24]

Hi @abichoi,
Yes you can access the tracker id of the objects that crossed the line zone like this:

zone = LineZone()
for frame in frames:
  # get the detections as normal
  detections_in_zone = detections[zone.trigger(detections=detections)]
  tracker_ids_in_zone = detections_in_zone.tracker_id

This will give you the detections in that zone at that frame. If you want to keep track of all of the detections that cross a line or enter a zone, you can just make a set with all of the tracker ids that gets added to every frame.

[SkalskiP]

Thanks for the help, @rolson24 🙏🏻 @abichoi. I'm converting this issue into a discussion if you have more questions.