• A Multiple Level-of-Detail 3D Data Transmission Approach for Low-Latency Remote Visualisation in Teleoperation Tasks

      Pacheco-Gutierrez, Salvador; orcid: 0000-0001-6575-1348; email: salvador.pacheco-gutierrez@ukaea.uk; Niu, Hanlin; orcid: 0000-0003-0457-0871; email: hanlin.niu@manchester.ac.uk; Caliskanelli, Ipek; orcid: 0000-0002-2641-3570; email: ipek.caliskanelli@ukaea.uk; Skilton, Robert; orcid: 0000-0003-1076-906X; email: robert.skilton@ukaea.uk (MDPI, 2021-07-14)
      In robotic teleoperation, the knowledge of the state of the remote environment in real time is paramount. Advances in the development of highly accurate 3D cameras able to provide high-quality point clouds appear to be a feasible solution for generating live, up-to-date virtual environments. Unfortunately, the exceptional accuracy and high density of these data represent a burden for communications requiring a large bandwidth affecting setups where the local and remote systems are particularly geographically distant. This paper presents a multiple level-of-detail (LoD) compression strategy for 3D data based on tree-like codification structures capable of compressing a single data frame at multiple resolutions using dynamically configured parameters. The level of compression (resolution) of objects is prioritised based on: (i) placement on the scene; and (ii) the type of object. For the former, classical point cloud fitting and segmentation techniques are implemented; for the latter, user-defined prioritisation is considered. The results obtained are compared using a single LoD (whole-scene) compression technique previously proposed by the authors. Results showed a considerable improvement to the transmitted data size and updated frame rate while maintaining low distortion after decompression.