TrackerState initial value is set wrong for n_init==1

[SajjadPSavoji]

Bug

In the boundary case of n_init==1, the current implementation fails to replicate the idea behind DeepSort.

Write now the default value of TrackState for a new Track instance is set to be equal to Tentative . This value is then updated upon the first match in the tracking. However, if n_init==1 and we have an immediate occlusion, as the track was marked tentative will never get to a match state and consequently, the TrackState will never change to Confirmed.

Fix

in the constructor of Track assign initial value to TrackState according to hits and n_init.

self.state = TrackState.Tentative if self.hits < self._n_init else TrackState.Confirmed

Compatibility

Adding this line does not effect the regular behaviour of the source code except for the boundary case discussed (n_init==1).

In case that n_init > 1, the expression simplifies to the following. Keep in mind that hits==1 in constructor.

self.state = TrackState.Tentative if 1 < self._n_init else TrackState.Confirmed

Or more simple as

self.state = TrackState.Tentative if True else TrackState.Confirmed

With final value equaling to

self.state = TrackState.Tentative

which is the the current behaviour of the source code.