Semantic annotation

An ontology for off-road scene understanding.

The annotation taxonomy extends the foundation of the RELLIS-3D dataset with terrain and object classes that appear frequently in the Great Outdoors sequences, including gravel and mulch.

Open Ontology Image
Great Outdoors Dataset ontology
Ontology definition for dataset labels.

Label set

Twenty-two classes for terrain, objects, and void regions.

The classes cover vegetation, traversable and non-traversable terrain, structures, agents, vehicles, obstacles, and unlabeled areas for semantic segmentation research.

  • Void
  • Dirt
  • Grass
  • Trees
  • Pole
  • Water
  • Sky
  • Vehicle
  • Object
  • Asphalt
  • Building
  • Log
  • Person
  • Fence
  • Bush
  • Concrete
  • Barrier
  • Puddle
  • Mud
  • Rubble
  • Mulch
  • Gravel
  • Snow

Caption annotation

Human-refined language labels for multimodal learning.

Captions are produced with a semi-automatic human-in-the-loop workflow designed to scale language annotation while keeping descriptions grounded in the visual data.

Representative frames

Dense image sequences are downsampled with CLIP-based visual features to select diverse frames across scene conditions.

Model drafts

Qwen2.5-72B generates initial short and long captions that summarize scenes, terrain, objects, and spatial context.

Human refinement

Annotators correct errors, reduce hallucinations, and standardize language so the final captions support vision-language and multimodal learning tasks.

Annotation examples

Representative RGB, LWIR, and language annotations.

This sample shows the paired visual annotations used in the release: semantic labels, RGB overlays, projected LWIR overlays, and human-refined captions.

Original RGB annotation sample
Original RGB image from a snowy off-road sequence near a utility building.
Semantic segmentation label map for RGB sample
Semantic segmentation label map.
Semantic segmentation overlay on RGB sample
RGB image with semantic labels overlaid.
LWIR annotation sample
Paired LWIR image.
Projected semantic annotation overlay on LWIR sample
Projected semantic labels overlaid on the LWIR image.
Caption example

Short caption

Snow-covered trail with tire tracks leads toward a garage, flanked by bare trees and a utility pole under a clear sky.

Long caption

The scene shows uneven, snow-covered off-road terrain with tire tracks curving toward a gabled building with garage doors. A utility pole and leafless trees border the area, while the open snow field remains navigable with obstacle avoidance around the structure and pole.

Statistics

Class distribution and annotation examples.

These visual summaries help researchers understand the semantic distribution before training or evaluating models.

Annotation availability statistics
Annotation availability statistics.
Image class distribution
Image label distribution.
Pixel class distribution
Pixel label distribution.
Caption annotation coverage by split
Caption annotation coverage by split.