May 2019 – International Journal of Geo-Information
Project: The Smart Point Cloud
Lab: Geomatics Unit
Abstract and figures
Automation in point cloud data processing is central in knowledge discovery within decision-making systems.
The definition of relevant features is often key for segmentation and classification, with automated workflows presentingthe main challenges. In this paper, we propose a voxel-based feature engineering that better characterize point clusters andprovide strong support to supervised or unsupervised classification.
We provide different feature generalization levels to permit interoperable frameworks. First, we recommend a shape-based feature set (SF1) that only leverages the raw X, Y, Z attributes of any point cloud. Afterwards, we deriverelationship and topology between voxel entities to obtain a three-dimensional (3D) structural connectivity feature set(SF2). Finally, we provide a knowledge-based decision tree to permit infrastructure-related classification.
We study SF1/SF2 synergy on a new semantic segmentation framework for the constitution of a higher semanticrepresentation of point clouds in relevant clusters.
Finally, we benchmark the approach against novel and best-performing deep-learning methods while using the full S3DISdataset. We highlight good performances, easy-integration, and high F1-score (>85%) for planar-dominant classes that are comparable to state-of-the-art deep learning.
Point Cloud and its extracted voxel structure, where each octree level represents the grid voxels, each subdivided in subsequent eight voxel children.