Add dataset card

README.md

@@ -1,4 +1,20 @@
 ---
+license: cc-by-4.0
+language:
+- la
+- fr
+task_categories:
+- object-detection
+- image-segmentation
+size_categories:
+- n<1K
+pretty_name: HORAE-LSv2 — Books of Hours layout
+tags:
+- glam
+- manuscripts
+- document-layout-analysis
+- medieval
+- iiif
 dataset_info:
   features:
   - name: image
@@ -40,3 +56,123 @@ configs:
   - split: train
     path: data/train-*
 ---
+
+# HORAE-LSv2 — layout segmentation for Books of Hours
+
+555 annotated page images from 334 medieval and early-modern Books of Hours, manuscript and printed,
+marked up for page layout analysis. Created by the HORAE project at the [Institut de Recherche et
+d'Histoire des Textes](https://www.irht.cnrs.fr/) (IRHT-CNRS) with [Teklia](https://teklia.com/), and
+deposited on Zenodo in August 2025 as HORAE-LSv2 ([10.5281/zenodo.16919911](https://doi.org/10.5281/zenodo.16919911)).
+
+This repository is a format conversion of that deposit. Same images, same annotations, repackaged so
+it loads with `datasets` instead of requiring four zip files and three text encodings.
+
+## Two annotation systems over the same pages
+
+The deposit ships two independent markup schemes for the same 555 pages, and they do not map onto each
+other. Both are carried here rather than picking one.
+
+| Column | Scheme | Geometry | Count |
+|---|---|---|---|
+| `objects` | 14-class YOLO taxonomy | bounding boxes, COCO `[x, y, w, h]` in absolute pixels | 22,878 |
+| `regions` | 7-type Arkindex taxonomy plus subclasses | polygons | 22,964 |
+
+`regions` types and their subclasses:
+
+| Type | Count | Subclasses |
+|---|---|---|
+| text_line | 13,879 | calendar |
+| initial | 3,542 | simple_initial, decorated_initial, historiated_initial |
+| decoration | 2,412 | line_filler, ornament, music_notation, decorated_border, illustrated_border |
+| rubrication | 1,224 | red, blue, gold |
+| text | 896 | border_text |
+| single_page | 852 | calendar |
+| miniature | 159 | — |
+
+`text_line` is 60% of the polygon annotations. Filter it out if you are after decorative or structural
+elements rather than lines.
+
+## Structure
+
+| Field | Type | Notes |
+|---|---|---|
+| `image` | image | JPEG at maximum available IIIF resolution |
+| `file_name` | string | source filename; institution and shelfmark are encoded in it |
+| `width`, `height` | int32 | as declared upstream; verified to match the decoded image |
+| `iiif_url` | string | the IIIF source URL, preserved for provenance |
+| `objects` | list of struct | `bbox`, `category_id`, `category_name` |
+| `regions` | list of struct | `polygon`, `type`, `class_name` |
+
+## Caveats
+
+**Not every page is annotated.** 555 images, but only 545 carry YOLO labels and 542 carry polygon
+regions. Roughly 13 pages have an image and nothing else. This is in the source deposit, not introduced
+by the conversion. Filter on `len(objects) > 0` or `len(regions) > 0` before training.
+
+**There are no splits.** The upstream README documents `metadata/train.csv`, `val.csv` and `test.csv`;
+none of those files exist in the published archive, including in `extras.zip`. Everything is in a single
+`train` split. Make your own splits — and group by manuscript, not by page, since 555 pages come from
+only 334 books and pages from the same book are highly correlated.
+
+**No transcriptions.** The upstream documentation describes `text_line` elements as carrying
+transcription data. The published `elements.csv` has no transcription column, so none is present here.
+This is a layout dataset only.
+
+**Dating is unknown per item.** The deposit does not ship per-manuscript dates, so there is no date
+field. "Medieval and early modern" is the collection-level description, not something you can filter on.
+
+### If you go back to the original deposit
+
+The three annotation files are in three different text encodings, which is worth knowing before you
+parse them yourself:
+
+| File | Encoding |
+|---|---|
+| `extras/HORAE_LSv2.csv` | UTF-8 |
+| `metadata/HORAE_LSv2_elements.csv` | latin-1 |
+| `metadata/HORAE_LSv2_image_data.csv` | UTF-7 (`+AF8-` for `_`) |
+
+Reading any of them as UTF-8 either raises or silently mangles every accented library name. The
+conversion here decodes each with its own encoding.
+
+The 2019 first release (HORAE_LS) referenced images by IIIF URL rather than shipping them; those URLs
+rotted, which is why v2 exists with images included.
+
+## Load
+
+```python
+from datasets import load_dataset
+
+ds = load_dataset("davanstrien/horae-lsv2-layout", split="train")
+
+# pages with decorative elements only — text_line is 60% of the polygons
+decorated = ds.filter(
+    lambda r: any(x["type"] in {"miniature", "initial", "decoration"} for x in r["regions"])
+)
+```
+
+## Licence
+
+CC BY 4.0, following the upstream deposit. Attribution to the HORAE project creators, below.
+
+Note that the source institutions holding the digitised manuscripts apply their own terms to the
+underlying images; the Zenodo deposit is the layer licensed CC BY 4.0. Where you need to go back to an
+institution's own copy, `iiif_url` points at it.
+
+## Credit
+
+Data created by Dominique Stutzmann and Lise Bernard Leterme (Institut de Recherche et d'Histoire des
+Textes), Mélodie Boillet and Christopher Kermorvant (Teklia), and Marie-Laurence Bonhomme.
+Converted and repackaged for the Hub by [Daniel van Strien](https://huggingface.co/davanstrien).
+
+```bibtex
+@dataset{stutzmann_2025_horae_lsv2,
+  author    = {Stutzmann, Dominique and Bernard Leterme, Lise and Boillet, M{\'e}lodie and
+               Bonhomme, Marie-Laurence and Kermorvant, Christopher},
+  title     = {{HORAE-LSv2. Layout Segmentation Dataset for Medieval Books of Hours}},
+  year      = {2025},
+  version   = {2.0},
+  publisher = {Zenodo},
+  doi       = {10.5281/zenodo.16919911}
+}
+```