codeShare's picture
Update README.md
d4684ad verified
|
Raw History Blame Contribute Delete
16.3 kB
metadata
pretty_name: Adcom Captioned AI Images
configs:
  - config_name: default
    data_files:
      - split: train
        path: captions.parquet
tags:
  - images
  - captions
  - ai-generated-images
  - natural-language
license: apache-2.0
language:
  - en

ADCOM Captioned AI Images

Dataset description

Adcom's captioned AI Images is a collection of images paired with associated captioning and descriptive metadata.

A notebook is provided for sampling this dataset at https://huggingface.co/datasets/codeShare/adcom_captioned_ai_images/blob/main/sample_multi_author_dataset_fixed.ipynb

This dataset does not have NSFW content aside from suggestive female oriented themes.

The repository uses an indexed storage layout designed to make image retrieval more efficient. Instead of storing all image data directly inside a single metadata file, it separates the metadata index from the image data.

The dataset consists of:

  • A Parquet metadata index: captions.parquet
  • JSONL image shards containing the image data
  • Byte offsets and record lengths in the Parquet index for direct image access

This layout allows users to retrieve individual images without downloading and scanning every image shard.

Repository structure

adcom_captioned_ai_images/
│
├── README.md
├── captions.parquet
│
└── [JSONL image shards]
    ├── ...
    └── ...

The exact shard paths are stored in the json_file column of captions.parquet. Use those paths rather than assuming fixed shard names.

1. Metadata index: captions.parquet

The Parquet file contains one metadata/index row per image.

Column Description
idx Image identifier
prompt Text prompt or caption associated with the image
tags Descriptive tags associated with the image
author Author or contributor
json_file Repository-relative path to the JSONL shard containing the image
byte_offset Zero-based byte offset of the JSONL record within that shard
byte_length Number of bytes to read for that record

The index columns json_file, byte_offset, and byte_length are used together to locate an image record directly.

Offsets and lengths refer to bytes, not character positions.

2. Image data: JSONL shards

Images are stored in JSONL files. Each line represents an individual image record encoded as JSON.

A record has the following structure:

{
  "idx": "IMAGE_ID",
  "image": "data:image/png;base64,..."
}

The image field contains a base64-encoded image, commonly represented as a data URI. Consumers should also allow for a raw base64 string.

The idx field identifies the image and corresponds to the idx value in the Parquet index.

3. How indexed retrieval works

For an image with a given idx:

  1. Find its row in captions.parquet.
  2. Read the row's json_file, byte_offset, and byte_length.
  3. Download the referenced JSONL shard.
  4. Seek to byte_offset in binary mode.
  5. Read byte_length bytes.
  6. Parse the JSON record and decode its base64 image.

This avoids scanning the entire shard for the selected image.


Quick start

Install dependencies

pip install pandas pyarrow pillow huggingface_hub

Load the metadata index

import pandas as pd
from huggingface_hub import hf_hub_download

REPO_ID = "codeShare/adcom_captioned_ai_images"

parquet_path = hf_hub_download(
    repo_id=REPO_ID,
    filename="captions.parquet",
    repo_type="dataset"
)

metadata = pd.read_parquet(parquet_path)

print(metadata.head())
print(f"Total indexed images: {len(metadata):,}")

For a private or gated repository, authenticate with a Hugging Face access token and pass it as the token argument to hf_hub_download.

Retrieve one image by ID

This example downloads only the shard containing the requested image and reads only the indexed record.

import json
import base64
import re
import io

import pandas as pd
from PIL import Image
from huggingface_hub import hf_hub_download

REPO_ID = "codeShare/adcom_captioned_ai_images"

# Load the metadata index.
parquet_path = hf_hub_download(
    repo_id=REPO_ID,
    filename="captions.parquet",
    repo_type="dataset"
)

metadata = pd.read_parquet(parquet_path)

# Choose an image ID from the index.
target_idx = str(metadata.iloc[0]["idx"])

# Find its index entry.
row = metadata.loc[
    metadata["idx"].astype(str) == target_idx
].iloc[0]

# Download only the required shard.
shard_path = hf_hub_download(
    repo_id=REPO_ID,
    filename=str(row["json_file"]),
    repo_type="dataset"
)

# Read the exact JSONL record using its byte location.
with open(shard_path, "rb") as f:
    f.seek(int(row["byte_offset"]))
    raw_record = f.read(int(row["byte_length"]))

record = json.loads(raw_record.decode("utf-8"))

# Verify the retrieved record.
assert str(record["idx"]) == target_idx

# Decode the image.
image_value = record["image"].strip()

if image_value.startswith("data:") and "," in image_value:
    image_value = image_value.split(",", 1)[1]

image_value = re.sub(r"\s+", "", image_value)

image_bytes = base64.b64decode(image_value)

image = Image.open(io.BytesIO(image_bytes)).convert("RGB")

display(image)

print("Image ID:", target_idx)
print("Prompt:", row["prompt"])
print("Author:", row["author"])
print("Tags:", row["tags"])

Retrieve a random sample of images

The following example samples metadata first and downloads only the shards needed for the selected images.

import json
import base64
import re
import io

import pandas as pd
from PIL import Image
from huggingface_hub import hf_hub_download

REPO_ID = "codeShare/adcom_captioned_ai_images"

NUM_SAMPLES = 10
RANDOM_SEED = 42

# Load the index.
parquet_path = hf_hub_download(
    repo_id=REPO_ID,
    filename="captions.parquet",
    repo_type="dataset"
)

metadata = pd.read_parquet(parquet_path)

# Optional author filter.
# Set to None to include all authors.
AUTHOR_FILTER = "Adcom"

if AUTHOR_FILTER is not None:
    metadata = metadata[
        metadata["author"].fillna("").astype(str).str.casefold()
        == AUTHOR_FILTER.casefold()
    ]

if metadata.empty:
    raise ValueError("No matching records found.")

# Reproducible random sample.
sampled = metadata.sample(
    n=min(NUM_SAMPLES, len(metadata)),
    random_state=RANDOM_SEED
)

# Download only the shards required by the sample.
shard_cache = {}

for _, row in sampled.iterrows():

    shard_name = str(row["json_file"])

    if shard_name not in shard_cache:
        shard_cache[shard_name] = hf_hub_download(
            repo_id=REPO_ID,
            filename=shard_name,
            repo_type="dataset"
        )

    # Retrieve the indexed JSONL record.
    with open(shard_cache[shard_name], "rb") as f:
        f.seek(int(row["byte_offset"]))
        raw_record = f.read(int(row["byte_length"]))

    record = json.loads(raw_record.decode("utf-8"))

    if str(record["idx"]) != str(row["idx"]):
        raise ValueError("Image ID does not match the metadata index.")

    # Decode image data.
    image_value = record["image"].strip()

    if image_value.startswith("data:") and "," in image_value:
        image_value = image_value.split(",", 1)[1]

    image_value = re.sub(r"\s+", "", image_value)

    image_bytes = base64.b64decode(image_value)
    image = Image.open(io.BytesIO(image_bytes)).convert("RGB")

    print("Image ID:", row["idx"])
    print("Prompt:", row["prompt"])
    print("Author:", row["author"])
    display(image)
    image.close()

Performance notes

  • Metadata-first sampling: Select records from the Parquet index before downloading image data.
  • Selective shard downloads: Only download shards referenced by the selected records.
  • Direct record access: Use byte offsets and lengths instead of scanning JSONL files.
  • Reproducible sampling: Set random_state to a fixed integer to reproduce a sample.
  • Private repository support: Pass a Hugging Face token to the download functions when authentication is required.

Important notes

  • The Parquet index and JSONL shards must remain consistent. If shard contents are rewritten or reordered, the corresponding byte offsets and lengths must be regenerated.
  • Image data is stored as base64 in JSONL records; it is decoded into image bytes when retrieved.
  • The dataset card does not declare a license. Please consult the dataset owner for licensing and usage permissions before redistributing or using the data commercially.

Browsing images and captions in the repaired dataset

This repository stores its caption index and image records separately:

captions.parquet
images/
    part_00000.jsonl
    part_00001.jsonl
    ...

How the files relate

captions.parquet is the index. Each row describes a caption/image record and contains the information needed to locate the corresponding record in a JSONL shard.

The important fields are:

Field Meaning
idx Global, sequential record ID across the dataset
author Author/source associated with the record
json_file Repository-relative path to the JSONL shard
byte_offset Starting byte position of the JSONL record
byte_length Number of bytes belonging to that record

The json_file, byte_offset, and byte_length fields work together: open the named JSONL shard in binary mode, seek to byte_offset, and read exactly byte_length bytes. Decode those bytes as UTF-8 and parse the resulting JSON.

Important: idx is a global dataset ID. It is not an author-local ID and should not be interpreted as a line number or byte position. Use the byte reference fields to retrieve the JSONL record.

The JSONL record contains the corresponding record data, including its global idx and author information. The Parquet row and JSONL record refer to the same logical item.

1. Install dependencies

!pip -q install -U huggingface_hub pyarrow pandas

2. Load the Parquet index

import pyarrow.parquet as pq
from huggingface_hub import hf_hub_download

REPO_ID = "codeShare/adcom_captioned_ai_images"

parquet_path = hf_hub_download(
    repo_id=REPO_ID,
    repo_type="dataset",
    filename="captions.parquet",
)

captions = pq.read_table(parquet_path)

print("Rows:", captions.num_rows)
print("Columns:", captions.column_names)

3. Find a record using its global idx

For example, retrieve global record ID 123:

import pyarrow.compute as pc

def find_caption_row(global_idx):
    matches = pc.equal(captions["idx"], global_idx)
    result = captions.filter(matches)

    if result.num_rows == 0:
        raise KeyError(f"Global idx {global_idx} was not found.")

    if result.num_rows > 1:
        raise ValueError(
            f"Global idx {global_idx} occurs more than once."
        )

    return result.to_pylist()[0]


row = find_caption_row(123)

print("Global idx:", row["idx"])
print("Author:", row["author"])
print("JSONL shard:", row["json_file"])
print("Byte offset:", row["byte_offset"])
print("Byte length:", row["byte_length"])

You can also browse by author or other caption metadata using the Parquet columns:

import pandas as pd

df = captions.to_pandas()

print(df.head())
print(df["author"].value_counts())

4. Retrieve the exact JSONL record using its byte reference

This is the recommended random-access method. It does not require reading the entire JSONL shard or counting lines.

import json

def load_jsonl_record(row):
    shard_path = hf_hub_download(
        repo_id=REPO_ID,
        repo_type="dataset",
        filename=row["json_file"],
    )

    offset = int(row["byte_offset"])
    length = int(row["byte_length"])

    with open(shard_path, "rb") as f:
        f.seek(offset)
        record_bytes = f.read(length)

    if len(record_bytes) != length:
        raise IOError(
            f"Expected {length} bytes, got {len(record_bytes)}."
        )

    record = json.loads(record_bytes.decode("utf-8"))

    # Verify the Parquet-to-JSONL relationship.
    assert int(record["idx"]) == int(row["idx"]), (
        f"ID mismatch: Parquet={row['idx']}, "
        f"JSONL={record.get('idx')}"
    )

    if "author" in record and "author" in row:
        assert record["author"] == row["author"], (
            "Author mismatch between Parquet and JSONL."
        )

    return record


record = load_jsonl_record(row)

print(json.dumps(record, indent=2, ensure_ascii=False))

5. Browse a record by global ID

Combine the two operations into one helper:

def get_record(global_idx):
    row = find_caption_row(global_idx)
    record = load_jsonl_record(row)
    return row, record


row, record = get_record(123)

print("Global ID:", row["idx"])
print("Author:", row["author"])
print("Shard:", row["json_file"])
print("Record:")
print(json.dumps(record, indent=2, ensure_ascii=False))

6. Browse several records

global_ids = [0, 1, 2, 100, 123]

for global_idx in global_ids:
    try:
        row, record = get_record(global_idx)

        print(
            f"\nID={global_idx} | "
            f"author={row['author']} | "
            f"shard={row['json_file']}"
        )
        print(json.dumps(record, indent=2, ensure_ascii=False))

    except KeyError:
        print(f"Global ID {global_idx} not found.")

7. Inspect image-related fields

The JSONL record is the source of the image data and associated metadata. Field names and image encoding should be inspected from the record rather than assumed.

row, record = get_record(123)

print("Available fields:")
for key, value in record.items():
    print(f"{key}: {type(value).__name__}")

print("\nPotential image-related fields:")
for key, value in record.items():
    if any(term in key.lower() for term in ("image", "img", "url", "path")):
        print(f"{key}: {str(value)[:300]}")

If a record contains an image URL or a base64 data URI, the following example can preview it:

import base64
import requests
from io import BytesIO
from PIL import Image
from IPython.display import display

def preview_image_field(record):
    # Common URL field names.
    for key in ("image_url", "url"):
        value = record.get(key)
        if isinstance(value, str) and value.startswith(("http://", "https://")):
            response = requests.get(value, timeout=30)
            response.raise_for_status()
            display(Image.open(BytesIO(response.content)))
            return

    # Common base64 data URI field.
    for key in ("image", "image_data", "image_base64"):
        value = record.get(key)

        if not isinstance(value, str):
            continue

        if value.startswith("data:image/") and "," in value:
            encoded = value.split(",", 1)[1]
            image_bytes = base64.b64decode(encoded)
            display(Image.open(BytesIO(image_bytes)))
            return

        if key == "image_base64":
            image_bytes = base64.b64decode(value)
            display(Image.open(BytesIO(image_bytes)))
            return

    print(
        "No recognized URL or base64 image field was found. "
        "Inspect the record fields above to determine its image encoding."
    )


row, record = get_record(123)
preview_image_field(record)

Data integrity and access rules

  • Use idx as the global record identifier.
  • Use json_file to identify the JSONL shard.
  • Use byte_offset and byte_length together for exact random access.
  • Read JSONL files in binary mode when using byte offsets.
  • Decode the selected byte range as UTF-8 before parsing JSON.
  • Do not treat byte offsets as character offsets or line numbers.
  • Do not derive JSONL paths from author names or local IDs.
  • The Parquet index and JSONL record should agree on global idx and author.
  • When adding records, assign new global IDs after the current maximum and calculate byte offsets and lengths from the exact serialized UTF-8 JSONL bytes.

This structure allows efficient lookup of an individual record without loading every JSONL shard into memory.