Resumen:
We present a new compressed representation of free trajec
tories of moving objects. It combines a partial-sums-based structure that
retrieves in constant time the position of the object at any instant, with a
hierarchical minimum-bounding-boxes representation that allows deter
mining if the object is seen in a certain rectangular area during a time
period. Combined with spatial snapshots at regular intervals, the repre
sentation is shown to outperform classical ones by orders of magnitude
in space, and also to outperform previous compressed representations in
time performance, when using the same amount of space.
