tutorials/metadata.md

# Working with the Metadata

## Downloading all the metadata files at once

Install the huggingface-cli utility (via pip). You may then use the following command:

    huggingface-cli download Spawning/PD12M --repo-type dataset --local-dir metadata --include "metadata/*"

## metadata format

The metadata files are in parquet format, and contain the following attributes:
- `id`: A unique identifier for the image.
- `url`: The URL of the image.
- `s3_key`: The S3 file key of the image.
- `caption`: A caption for the image.
- `hash`: The MD5 hash of the image file.
- `width`: The width of the image in pixels.
- `height`: The height of the image in pixels.
- `mime_type`: The MIME type of the image file.
- `license`: The URL of the license.
- `source`: The source organization of the image.

#### Open a metadata file
The files are in parquet format, and can be opened with a tool like `pandas` in Python. 
```python
import pandas as pd
df = pd.read_parquet('pd12m.000.parquet')
```

#### Get URLs from metadata 
Once you have opened a maetadata file with pandas, you can get the URLs of the images with the following command:
```python
urls = df['url']
```

### Download all files mentioned in metadata

If you want to just grab all files referenced by a metadata collection, you may try this (adjust to taste):

    img2dataset --url_list $file --input_format "parquet" \
    --url_col "url" --caption_col "caption" --output_format files \
    --output_folder $dir --processes_count 16 --thread_count 64 \
    --skip_reencode true --min_image_sizel 654 --max_aspect_ratio=1.77