An Online Trajectory Compression Based on Retrace Point Detection

摘要

In confronting plenty of trajectory records are generated and stored by GPS-equipped mobile devices making the device memory suffer a heavy storage pressure, it is a vital issue to compress the trajectories. This paper proposes a trajectory compression algorithm Velocity Preserving Trajectory Compression based on Retrace Point Detection (VPTR). In VPTR, the retrace points and the velocity errors are taken to reflect the speeds and directions attached with the points. VPTR first determines whether the points to be retrace points on basis of the changed movement directions, and then the retrace points are extracted from the original trajectories. Especially, the retrace points are put in a buffer, and the sub-trajectories in the buffer are compressed according to the measured velocity errors. Simulations are carried out on the Geolife trajectory dataset, and the simulation results indicate that VPTR can achieve a preferable trade-off among the compression error, compression ratio and running time.