---
language:
- cs
license: cc-by-4.0
task_categories:
- text-classification
- clustering
tags:
- historical-newspapers
- document-layout
- Czech
- article-segmentation
pretty_name: Czech Historical Newspapers
size_categories:
- n<1K
configs:
- config_name: pages
  data_files: data/pages-*.parquet
- config_name: annotations
  data_files: data/annotations-*.parquet
---

# Czech Historical Newspapers

Scanned pages of Czech historical newspapers annotated with layout regions and ground-truth article cluster labels. The dataset is designed for **unsupervised clustering experiments**: the task is to group text regions on each page into the articles they belong to, using only text content or visual features.

## Dataset structure

Two configurations are available:

### `pages` (30 rows — one per newspaper page)

| Column | Type | Description |
|---|---|---|
| `image_id` | int | Page ID (1–30) |
| `image_name` | str | Filename, e.g. `Brnenske_48_D.jpg` |
| `series` | str | Newspaper series (`Brnenske` or `Lidove`) |
| `issue` | str | Issue number within the series |
| `page` | str | Page letter within the issue |
| `texts` | list[str] | OCR text of each text region, in scan order |
| `category_ids` | list[int] | Category ID for each text region |
| `category_names` | list[str] | Category name for each text region |
| `cluster_labels` | list[int] | Ground-truth article cluster index for each region |
| `num_texts` | int | Number of text regions on the page |
| `num_clusters` | int | Number of distinct articles on the page |

```python
from datasets import load_dataset
ds = load_dataset("your-username/czech-historical-newspapers", "pages")
row = ds["train"][0]
# row["texts"]          -> list of OCR strings
# row["cluster_labels"] -> ground-truth article assignment per text
```

### `annotations` (881 rows — one per text region)

| Column | Type | Description |
|---|---|---|
| `annotation_id` | int | Original annotation ID |
| `image_id` | int | Page ID |
| `image_name` | str | Filename |
| `series` | str | `Brnenske` or `Lidove` |
| `issue` | str | Issue number |
| `page` | str | Page letter |
| `category_id` | int | Region type ID |
| `category_name` | str | Region type name |
| `text` | str | OCR text content |
| `bbox_x/y/w/h` | int | Bounding box in pixels [x, y, width, height] |
| `cluster_label` | int | Ground-truth article cluster index |

```python
ds = load_dataset("your-username/czech-historical-newspapers", "annotations")
# Filter to a single page
page = ds["train"].filter(lambda x: x["image_name"] == "Brnenske_48_D.jpg")
```

## Category types

Annotations belong to one of the following layout region types. Categories 1, 3, 6, and 7 are excluded from both configs (no text content).

| ID | Name | Kept | Count |
|---|---|---|---|
| 1 | SeparatorRegion | No | 297 |
| 2 | Heading | Yes | 132 |
| 3 | Caption | No | 67 |
| 4 | Enumeration | Yes | 17 |
| 5 | TextRegion | Yes | 572 |
| 6 | ImageRegion | No | 83 |
| 7 | Article | No | 0 |
| 8 | TableRegion | Yes | 1 |
| 9 | AdvertRegion | Yes | 159 |

## Statistics

- **30 pages** from 2 Czech historical newspaper series
- **12 Brnenske pages** (issues 09, 44, 48) and **18 Lidove pages** (issues 04, 06, 07)
- **881 text annotations** with ground-truth labels
- **1–27 articles per page** (median ~7)
- Text is in Czech; embeddings from multilingual models are recommended

## Intended use

The ground-truth `cluster_labels` are the reference for evaluating clustering algorithms (K-Means, Spectral Clustering, Affinity Propagation, etc.) using metrics such as Adjusted Rand Index and Normalized Mutual Information.

Images are not included. The original scans are high-resolution JPEGs (~3500×5100 px).

## Annotation

Annotated by "honza" using bounding-box tools. Bounding boxes follow the COCO convention `[x, y, width, height]` in pixels.