SARCLIP: Multimodal Foundation Model for SAR Imagery

🚀 Overview

SARCLIP is a multimodal foundation model specifically designed for Synthetic Aperture Radar (SAR) imagery based on the Contrastive Language-Image Pre-training (CLIP) framework. SARCLIP enables cross-modal understanding between SAR images and textual information, supporting zero-shot classification, cross-modal retrieval, and image-text inference.

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🛠 Installation

Environment Requirements

• Operating System: Linux or Windows
• Python: ≥ 3.8
• CUDA: Compatible CUDA version as supported by PyTorch

Dependencies

Install required Python libraries:

pip install -r requirements.txt

Hardware Recommendations

• GPU: NVIDIA RTX3060 or higher
• Memory: ≥ 16GB RAM
• VRAM: ≥ 12GB GPU Memory
• Disk: ≥ 30GB free disk space

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📂 Project Structure

SARCLIP-main/
├── sar_clip/
│   ├── model_configs/     # Model configs & pre-trained weights
│   ├── *.py               # Core model code
├── data/                  # Dataset directory
├── retrieval.py           # Cross-modal retrieval script
├── zero-shot.py           # Zero-shot classification script
├── zero-shot-inference.py # Image-text inference script
├── example.py             # Demonstration script
├── requirements.txt
├── README.md

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🚩 Quick Start

Zero-Shot Classification

Update CLASSNAMES and TEMPLATES in zero-shot.py, then execute:

python zero-shot.py \
  --imagenet-val "./data/zero-shot" \
  --batch-size 8 \
  --model "ViT-B-32" \
  --cache-dir "./sar_clip/model_configs/ViT-B-32" \
  --pretrained "./sar_clip/model_configs/ViT-B-32/vit_b_32_model.safetensors"

Cross-Modal Retrieval

Execute the retrieval script (Extract the ./data/retrieval/retrieval.rar file first):

python retrieval.py \
  --val-data "./data/retrieval_file_list.csv" \
  --csv-img-key "filename" \
  --csv-caption-key "caption" \
  --batch-size 8 \
  --model "ViT-B-32" \
  --cache-dir "./sar_clip/model_configs/ViT-B-32" \
  --pretrained "./sar_clip/model_configs/ViT-B-32/vit_b_32_model.safetensors"

Image-Text Inference

Run inference directly on images:

python zero-shot-inference.py \
  --image-dir "path/to/images" \
  --batch-size 8 \
  --model "ViT-B-32" \
  --cache-dir "./sar_clip/model_configs/ViT-B-32" \
  --pretrained "./sar_clip/model_configs/ViT-B-32/vit_b_32_model.safetensors"

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Example Output

Running example.py provides a visualization and outputs textual predictions:

Predictions:
- an SAR image of urban zones                        1.0000
- an SAR image of water areas                        0.0000
- an SAR image of croplands                          0.0000
- one solitary marine craft is visible in the right region . 0.0000
- along the right side , several storage tanks are be detected . 0.0000
- 1 aircraft is found throughout the frame .         0.0000

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❓ Troubleshooting

• Out of Memory (OOM): Decrease --batch-size.
• Model Loading Failed: Verify the correct path to the pretrained model.
• GPU Not Used: Ensure CUDA and PyTorch compatibility.

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📌 License

• Code: Released under the MIT License.
• Dataset (SARCAP): Released under a separate Dataset License, for non-commercial research and educational use only.

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💾 Model Weights & Dataset Access

Pretrained Model Weights

The pretrained SARCLIP weights are publicly available for research and non-commercial use.

• SARCLIP Weights: 🔗 Baidu Netdisk (Extraction code: dizf)

To use the pretrained weights, place them under:

./sar_clip/model_configs/{MODEL_NAME}/

Dataset Access

All released data are intended for non-commercial research and educational purposes only.

• SARCAP Dataset: 🔗 Baidu Netdisk (Extraction code: 2nxm)
• Zero-Shot: 🔗 Baidu Netdisk (Extraction code: quh2)

Dataset structure:

SARCAP/
├── img/                   # SAR image patches
├── img_caption.csv        # Image-text pairs

To use the zero-shot examples, place them under:

./data/zero-shot/

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📚 Citation

If you use SARCLIP, please cite:

@misc{SARCLIP2025,
  author = {CAESAR-Radi},
  title = {SARCLIP: A Multimodal Foundation Framework for SAR Imagery via Contrastive Language-Image Pre-Training},
  year = {2025},
  publisher = {GitHub},
  url = {https://github.com/CAESAR-Radi/SARCLIP}
}

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🌟 Acknowledgements

We thank the following organizations for providing datasets and inspiration:

• Capella Space (Capella SAR Data)
• ESA Copernicus Programme (WorldCover)
• Anhui University (OGSOD)
• University of Electronic Science and Technology of China (RSDD)
• Huazhong University of Science and Technology (SADD)
• Chinese Academy of Sciences (SIVED)
• Technical University of Munich (SEN12MS)

Special thanks to the OpenCLIP team for their significant contributions.