CPR Tracking Replicate Storage, Memory Usage - kristinbranson/APT GitHub Wiki

The full output of CPR tracking for a single (frame,target) is an array of size nRep x npts x 2 x (nIter+1), where nRep is the number of Tracking replicates, npts is the number of landmarks, and nIter is the number of CPR iterations.

Storing full CPR tracking results can become very memory intensive for movies with many frames, targets, landmarks, etc. Under Track>'Store tracking replicates' there are three options for how much information to retain:

  1. Don't store replicates. Only the final/pruned tracking results are retained and no information about replicates is retained.
  2. Store replicates, final iteration only. Along with the final/pruned tracking results, the final iteration of the CPR regressor cascade is retained for all replicates. This enables visualization of the replicate cloud or eg computation of replicate dispersion for all tracked frames.
  3. Store replicates, all iterations. This stores the full CPR tracking output.

View>Show predicted replicates requires option 2. or 3. above. Track>View tracking diagnostics works best with 3., but will also work to a limited extent with 2.

Examples of full tracking size:
 - 50K frames/mov, 20 tgts, 50 reps, D=34 (npts=17), T=80. 
   - Track single mov, all tgts, reduced only: 340MB 
   - Track single mov, all tgts, full: 1.36T **too big**
   - Track single mov, all tgts, final iter only: 17GB. **quite big**
   - Track single mov, single tgt, reduced only: 17MB 
   - Track single mov, single tgt, full: 68GB **too big**
   - Track single mov, single tgt, final iter only: 1GB
 - 200K frames/mov, 1 tgt, 50 reps, D=4 (npts=2), T=50.
   - Track single mov, all tgts, reduced only: 8MB
   - Track single mov, all tgts, full: 20GB **quite big**
   - Track single mov, all tgts, final iter only: 400MB
 - 3K frames/mov, 1 tgt, 50 reps, D=4, T=40
   - Track single mov, all tgts, reduced only: 120KB
   - Track single mov, all tgts, full: 240MB
   - Track single mov, all tgts, final iter only: 6MB