Question about memory update

[artofstate]

In the update_memory function, what is the principle behind determining whether an instance is being tracked by comparing the propagated_id with num_tracks? My understanding is that num_tracks refers to the number of queries retained from the previous frame, while propagated_id refers to the index of the retained query among all predicted queries. Is this correct?

[woodfrog]

In the update_memory function, what is the principle behind determining whether an instance is being tracked by comparing the propagated_id with num_tracks? My understanding is that num_tracks refers to the number of queries retained from the previous frame, while propagated_id refers to the index of the retained query among all predicted queries. Is this correct?

Yes, that's right. You can also use the visualization script, which puts the track id on each road element across each frame -- this tells if the tracking works as expected.