ByteTrack memory consumption increases indefinitely about supervision HOT 4 CLOSED

Hi, @tc360950! 👋🏻 I completely agree that the problem exists. Why do you think storing values from the last pass is enough?

from supervision.

Hi @SkalskiP, removed_tracks collection is only used on line 489

self.lost_tracks = sub_tracks(self.lost_tracks, self.removed_tracks)

where it's used to get rid of lost tracks which have been marked for removal (i.e. those which have not been matched to a detection for a predefined time). Since tracks marked for the removal in the latest pass are added to removed_tracks collection on line 490

self.removed_tracks.extend(removed_stracks)

lost tracks which were removed on pass no. N will actually be removed (i.e. moved to removed_tracks collection) after pass no. N + 1 (which btw is another error, although without any dire consequences). This implies that we must at least do (which is what I propose):

self.removed_tracks = removed_stracks

Now, as to why this is enough. Once a track lands in removed_tracks it does not get out anywhere. I.e. once track is removed from lost_tracks on line 489, it will not reappear there. As a result we do not need to keep whole history, only most recently removed tracks are needed to "sanitize" lost_tracks collection.

I agree that it's a risky change, since there are no unit tests for ByteTrack (I can of course come up with some scripts which compare results from both versions on hand crafted or random data (which I did before raising this issue) but it still seems "not quite right"). There is an open PR with unit tests for ByteTrack. I have not looked at it but maybe that's the best way to introduce this change - add good unit tests for ByteTrack.

from supervision.

Hi @tc360950 👋🏻 Thank you for explaining your thought process. The ByteTrack code was transferred to Supervision (with minor changes) from another codebase, which is why it slightly deviates from the writing style we have in Supervision and, as you rightly observed, is not tested at all. Thanks a lot for the analysis you conducted.

from supervision.

I'm closing this PR as #1166 was just merged.

from supervision.