How to kill tracks when they leave scene? about norfair

[ManuConcepBrito]

Thanks for the help! I finally figured out the issue. We were only passing detections to the tracker when a detection was in the frame so we skipped the empty frames and that's why it didn't kill the tracked objects.

[joaqo]

Hi @Maiabrennerst!

Is it because of occlusion? Like they overlap and their id gets transferred between them?

Thats a hard problem to fix. Depending on the nature of your problem, it be improved by making object max inertia be lower, or by using embeddings to reid the vehicles.

[nikky4D]

How do we include embeddings in the tracker for reid? And can we get embeddings for any model or is there a specific model we should use for our tracking problem? Is there an example that uses embeddings?

[ManuConcepBrito]

Thanks for the quick reply! So what happens with more detail is:

1. An object leaves the scene
2. A couple of frames go by without any object
3. A second object (different from the first one) enters the scene very close to where the first object left
4. The tracker matches both objects as the same one.

I am thinking of maybe an embedding that takes into account the direction of the objects (as the first and second go in different directions), but I am quite clueless at the moment. Is there any documentation on recommended embeddings?

[joaqo]

@ManuConcepBrito That is odd, if the object leaves the scene for some time the object_id should be removed from the pool, and a new object_id should be assigned for the object that enters the scene. You may have your hit_inertia_max be too high.

@nikky4D Just set past_detections_length to how many detections you want to keep through the life of the project, and then if you want embeddings just add embeddings to the .data property of the object, which you can later use in you distance function. This is not properly documented at the moment, and there are no examples, but we'll add some soon. Docs

[joaqo]

Awesome!