---
license: cc0-1.0
task_categories:
- image-to-text
tags:
- chemistry
- molecular-structure
- smiles
- ocr
- computer-vision
- webdataset
- lightonocr
size_categories:
- 1M<n<10M
---

# BMS Molecular Translation - WebDataset Shards

This dataset contains pre-processed WebDataset shards of the BMS Molecular Translation dataset, 
optimized for fast data loading during model training.

## Dataset Summary

- **Total Size**: 3.8 GB
- **Training shards**: 236 files (3.7 GB) - 2.36M molecular structure images with SMILES
- **Validation shards**: 5 files (0.1 GB) - 48K samples for model validation  
- **Test shards**: 3 files (0.0 GB) - 24K held-out samples for final evaluation

## Format

Shards are in [WebDataset](https://github.com/webdataset/webdataset) format:
- Sequential tar archives for fast I/O
- 10,000 samples per shard
- Training data pre-shuffled
- Val/test data in original order
- **Tar files are preserved** (not extracted) - perfect for WebDataset!

## Usage

### Download the Dataset

```bash
# Using HuggingFace Hub
pip install huggingface_hub

# Download entire dataset
python download_shards_from_huggingface.py --username jeffdekerj

# Or use HuggingFace Hub directly
from huggingface_hub import snapshot_download
snapshot_download(
    repo_id="jeffdekerj/bms-images-shards",
    repo_type="dataset",
    local_dir=".data/webdataset_shards"
)
```

### Load with WebDataset

```python
from webdataset_loader import BMSWebDataset
from transformers import AutoProcessor

processor = AutoProcessor.from_pretrained("lightonai/LightOnOCR-1B-1025")

train_dataset = BMSWebDataset(
    shard_dir=".data/webdataset_shards/train/",
    processor=processor,
    user_prompt="Return the SMILES string for this molecule.",
    shuffle_buffer=1000,
)
```

### Train Your Model

```bash
python finetune_lightocr.py \
  --train_shards .data/webdataset_shards/train/ \
  --val_shards .data/webdataset_shards/val/ \
  --per_device_train_batch_size 4 \
  --num_train_epochs 3 \
  --fp16
```

## Benefits

- **2-5x faster** data loading vs individual files
- **Better I/O** performance for network filesystems
- **Lower overhead** with sequential reads
- **Built-in shuffling** without memory overhead
- **Tar files preserved** - no auto-extraction like Kaggle

## Source Repository

GitHub: https://github.com/JeffDeKerj/lightocr

Complete documentation available in the repository:
- `docs/WEBDATASET_GUIDE.md` - Complete usage guide
- `docs/HUGGINGFACE_GUIDE.md` - HuggingFace-specific guide
- `docs/FINETUNE_GUIDE.md` - Fine-tuning guide
- `README.md` - Project overview

## Original Dataset

Based on the BMS Molecular Translation competition dataset:
https://www.kaggle.com/c/bms-molecular-translation

## Citation

If you use this dataset, please cite both:
1. The original BMS Molecular Translation competition
2. The LightOnOCR model (if applicable to your work)

## License

CC0: Public Domain. Free to use for any purpose.