Lots of updates have been made to abstract the data loading process.
However, now that multiple files can be read in, and speckle patterns formed,
it is apparent that detected photon data from consecutive time steps (e.g. t=1 to t=2)
produce different speckle patterns. This should not happen since ultrasound has not
started propagating through the medium yet. This probably has to do with some
synchronization error between workgroups.

TO DO:
- Figure out why speckle patterns are not identical for two consecutive steps before
  ultrasound.