Compact and indexed representation for LiDAR point clouds

[Abstract]: LiDAR devices are capable of acquiring clouds of 3D points reflecting any object around them, and adding additional attributes to each point such as color, position, time, etc. LiDAR datasets are usually large, and compressed data formats (e.g. LAZ) have been proposed over the years. These formats are capable of transparently decompressing portions of the data, but they are not focused on solving general queries over the data. In contrast to that traditional approach, a new recent research line focuses on designing data structures that combine compression and indexation, allowing directly querying the compressed data. Compression is used to fit the data structure in main memory all the time, thus getting rid of disk accesses, and indexation is used to query the compressed data as fast as querying the uncompressed data. In this paper, we present the first data structure capable of losslessly compressing point clouds that have attributes and jointly indexing all three dimensions of space and attribute values. Our method is able to run range queries and attribute queries up to 100 times faster than previous methods. Secretara Xeral de Universidades; [ED431G 2019/01] Ministerio de Ciencia e Innovacion; [PID2020-114635RB-I00] Ministerio de Ciencia e Innovacion; [PDC2021-120917C21] Ministerio de Ciencia e Innovación; [PDC2021-121239-C31] Ministerio de Ciencia e Innovación; [PID2019-105221RB-C41] Xunta de Galicia; [ED431C 2021/53] Xunta de Galicia; [IG240.2020.1.185]