Persisting index of track across multiple batches

[georgejsamuel]

Since tracks are outputted as a list of coordinates. The index to that coordinate is the index of the track. How do you persist the index of a track across multiple batches as people are entering and exiting the frame?

For example, say you are processing frames from times t, t+1, and t+2, two frames at a time. When processing t and t+1: •At time t, KSP outputs 3 tracks [track1, track2, track3]. •At time t+1, the person which corresponds to track2 exits the area. So, at t+1 the track2 has (row, col) = (0, 0). Now, when processing t+1 and t+2: •KSP outputs 2 tracks [track1, track3]. Both tracks are non-zero. However, how do we persist the identity of track3 as it is now ambiguous whether the second list in the track is track2 or track3 from the previous batch?