TerraCodec-1.0-TT-S2L2A

TerraCodec

Neural Compression for Earth Observation

TerraCodec (TEC) is a family of pretrained neural compression codecs for multispectral Sentinel-2 satellite imagery. The models compress optical Earth observation data using learned latent representations and entropy coding.

Compared to classical codecs such as JPEG2000 or WebP, TerraCodec achieves 3–10× higher compression at comparable reconstruction quality on multispectral satellite imagery. Temporal models further improve compression by exploiting redundancy across seasonal image sequences of satellite imagery.

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Model Family

Lower λ / quality → higher compression
Higher λ / quality → higher reconstruction quality

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Model Architecture

This repository contains the TEC-TT (Temporal Transformer) variants of TerraCodec.

TEC-TT extends the TerraCodec image codecs by modeling temporal dependencies across satellite image sequences. Each frame is first encoded using an ELIC-style CNN encoder–decoder to obtain latent representations. A temporal transformer then predicts the probability distribution of the current frame’s latents conditioned on previously encoded frames. By exploiting redundancy across seasonal observations, TEC-TT achieves improved compression efficiency for multi-temporal Sentinel-2 imagery.

See the paper for additional architectural and training details.

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Input Format

• Inputs use 12 Sentinel‑2 L2A spectral bands.
• Recommended spatial size: 256×256.
• Temporal codecs were pretrained on four seasonal frames, but can process any number of timesteps during inference (higher T increases compute).

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Normalization

Models were trained on SSL4EO-S12 v1.1.

Inputs should be standardized per spectral band using dataset statistics. For S2L2A:

mean = torch.tensor([793.243, 924.863, 1184.553, 1340.936, 1671.402, 2240.082, 2468.412, 2563.243, 2627.704, 2711.071, 2416.714, 1849.625])
std = torch.tensor([1160.144, 1201.092, 1219.943, 1397.225, 1400.035, 1373.136, 1429.170, 1485.025, 1447.836, 1652.703, 1471.002, 1365.307])

Usage

Install TerraCodec:

pip install terracodec

Load pretrained models:

from terracodec import terracodec_v1_tt_s2l2a

model = terracodec_v1_tt_s2l2a(
    pretrained=True,
    compression=5
)

# Fast reconstruction (no bitstream)
reconstruction = model(inputs)

# True compression
compressed = model.compress(inputs)
reconstruction = model.decompress(**compressed)

Feedback

If you have questions, encounter issues or want to discuss improvements:

• open an issue or discussion on GitHub
• or contribute directly to the repository

GitHub repository: https://github.com/IBM/TerraCodec

Citation

If you use TerraCodec in your research, please cite:

@article{terracodec2025,
  title   = {TerraCodec: Compressing Optical Earth Observation Data},
  author  = {Costa Watanabe, Julen and Wittmann, Isabelle and Blumenstiel, Benedikt and Schindler, Konrad},
  journal = {arXiv preprint arXiv:2510.12670},
  year    = {2025}
}