---
license: cc-by-4.0
configs:
- config_name: default
  data_files:
  - split: train
    path: data/train-*
  - split: validation
    path: data/validation-*
  - split: test
    path: data/test-*
dataset_info:
  features:
  - name: image_id
    dtype: string
  - name: image_before
    dtype: image
  - name: image_after
    dtype: image
  - name: label
    dtype: image
  - name: dep
    dtype: string
  - name: epsg
    dtype: int32
  - name: patch_size
    list: int32
  - name: patch_bounds
    dtype: string
  - name: year_before
    dtype: int32
  - name: year_after
    dtype: int32
  splits:
  - name: train
    num_bytes: 19237579701
    num_examples: 25908
  - name: validation
    num_bytes: 778303470
    num_examples: 984
  - name: test
    num_bytes: 771375873
    num_examples: 979
  download_size: 20780292545
  dataset_size: 20787259044
task_categories:
- mask-generation
- image-segmentation
tags:
- Geospatial
- Remote Sensing
- Building Change Detection
size_categories:
- 10K<n<100K
---
# FOTBCD-Binary

A large-scale building change detection benchmark from French orthophotos and topographic data.

## Dataset Description

| Property | Value |
|----------|-------|
| **Departments** | 28 (25 train / 3 eval) |
| **Image pairs** | ~28k |
| **Patch size** | 512×512 |
| **Resolution** | 0.2m |
| **Annotation** | Binary mask |

## Splits

| Split | Examples |
|-------|----------|
| train | ~26k |
| val   | ~1k |
| test  | ~1k |

## Features

| Field | Type | Description |
|-------|------|-------------|
| `image_id` | string | Unique identifier |
| `image_before` | Image | Before image (RGB) |
| `image_after` | Image | After image (RGB) |
| `label` | Image | Binary mask (0=unchanged, 255=changed) |
| `dep` | string | French department code |
| `epsg` | int | Coordinate reference system |
| `patch_bounds` | string | Geographic bounds (JSON) |
| `year_before` | int | Year of before image |
| `year_after` | int | Year of after image |

## Usage

```python
from datasets import load_dataset

ds = load_dataset("retgenai/FOTBCD-Binary")

example = ds["train"][0]
example["image_before"].show()
example["image_after"].show()
example["label"].show()
```
## License

- **Source**: BD ORTHO / BD TOPO by IGN under [Licence Ouverte 2.0](https://alliance.numerique.gouv.fr/licence-ouverte-open-licence/)

## Citation

If you use FOTBCD in your research, please cite our paper:

```bibtex
@misc{moubane2026fotbcd,
      title={FOTBCD: A Large-Scale Building Change Detection Benchmark from French Orthophotos and Topographic Data},
      author={Abdelrrahman Moubane},
      year={2026},
      eprint={2601.22596},
      archivePrefix={arXiv},
      primaryClass={cs.CV},
      url={https://arxiv.org/abs/2601.22596},
}
```