FRACTAL Dataset Overview

Basic Information

• Name: FRACTAL
• Type: 3D Point‑Cloud Semantic Segmentation Benchmark
• Size: 100,000 point clouds
• Coverage Area: 250 km²
• Source: Lidar HD Program (2020‑2025)
• Point Density: 10 pulses/m², average 37 pts/m², total 9,261 M points
• Semantic Classes: 7 (Other | Ground | Vegetation | Building | Water | Bridge | Permanent Structure)
• Colorization: Using high‑resolution aerial images from ORTHO HR®

Content

• Composition:
  • Training: 80,000 point clouds
  • Validation: 10,000 point clouds
  • Test: 10,000 point clouds
• Point Cloud Density: 10 pulses/m² (~40 pts/m²)
• Colorization: Near‑infrared, red, green, and blue channels at 0.2 m spatial resolution
• Acquisition Period: Spanning multiple years, up to a 3‑year gap possible

Class Distribution

Spatial Extent & Split

• Sampling Regions: Five spatial domains in southern France, total area 17,280 km²
• Split: 80 % training, 10 % validation, 10 % test
• Test Area: 25 km² sampled from continuous test zones across each domain, totaling 1,049 km²
• Training/Validation Area: 200 km² + 25 km², remaining area sampled using spatial stratification

Aerial Imagery

• Colorized Images: Provided in a separate repository, IGNF/FRACTAL‑IRGB

Citation

@misc{gaydon2024fractal, title={FRACTAL: An Ultra‑Large‑Scale Aerial Lidar Dataset for 3D Semantic Segmentation of Diverse Landscapes}, author={Charles Gaydon and Michel Daab and Floryne Roche}, year={2024}, eprint={TBD}, archivePrefix={arXiv}, url={https://arxiv.org/abs/TBD}, primaryClass={cs.CV} }

License

• License: "OPEN LICENCE 2.0/LICENCE OUVERTE", created by the French government to promote open data dissemination by public administration. Compatible with the UK Open Government Licence (OGL), Creative Commons Attribution (CC‑BY), and Open Data Commons Attribution (ODC‑BY).