biglam/icdar2021-historical-document-dating

ICDAR 2021 Historical Document Classification — Task 2 (Dating)

13,810 manuscript page images labelled with the period in which they were produced. Images come from e-codices, the virtual manuscript library of Switzerland.

Split	Images	Date range	Median span	Dated to a single year
train	11,294	800–1899	45 years	1,409
test	2,516	800–1921	49 years	264

The label is an interval, not a year

Palaeographers date a manuscript to a range, and the width of that range encodes their confidence. This dataset preserves that:

• date_start, date_end — the range as published
• date_span — end - start. 0 means dated to a single year.
• date_mid — midpoint, a convenience point-target

Precision varies enormously: some pages are pinned to one year (1505–1505), others sit inside a two-century window (1250–1449). Any sensible model or metric has to handle that heterogeneity — a plain regression on date_mid throws away the confidence signal, and a plain accuracy metric treats a two-century guess as equal to a one-year one. Consider weighting by date_span, or scoring interval overlap rather than point error.

Gotchas in the source deposit

Two things will silently corrupt a naive build. Both are handled here.

The two ground-truth files use different delimiters.

dating/training/gt.csv   img/0_1400_1430.jpg,1400,1430          <- COMMA
dating/test/gt.csv       img/667cd1e1....jpg;1200;1299          <- SEMICOLON

Parse both the same way and the test split collapses into a single junk column — with a plausible-looking row count. Verified: with the right delimiters, all 2,516 test images join to a label, and all 11,294 train images do too.

The test labels are NOT missing — despite appearances. Zenodo publishes a separate task2-dating-test-meta.csv alongside the archive that maps test images to their source manuscript and contains no dates at all. It is a provenance file, not the ground truth. The real test labels live inside dating.tar.gz at dating/test/gt.csv. Anyone glancing at the Zenodo file list would reasonably conclude this is a competition set with a withheld test split. It isn't.

Also: training filenames encode the range (5639_1467_1467.jpg), but test filenames are opaque hashes — you must use the CSV.

Load

from datasets import load_dataset

# 28 GB of page images - stream unless you want the whole deposit on disk
ds = load_dataset("biglam/icdar2021-historical-document-dating",
                  split="train", streaming=True)

# keep only tightly-dated pages; date_span == 0 means dated to a single year
tight = ds.filter(lambda r: r["date_span"] <= 25)

Source & credit

Mathias Seuret, Anguelos Nicolau, Dalia Rodríguez-Salas et al. ICDAR 2021 Historical Document Classification Dataset for Task 2 — Dating. Zenodo, 2021-05-28. https://zenodo.org/records/4836687 — CC-BY-4.0.

Images courtesy of e-codices, Virtual Manuscript Library of Switzerland. This repository converts the 28 GB deposit to Parquet. Please cite the original authors and the ICDAR 2021 competition.

@dataset{seuret_2021_icdar_dating,
  author    = {Seuret, Mathias and Nicolau, Anguelos and Rodr{\'i}guez-Salas, Dalia and
               Weichselbaumer, Nikolaus and Stutzmann, Dominique and Mayr, Martin and
               Maier, Andreas and Christlein, Vincent},
  title     = {{ICDAR 2021 Historical Document Classification Dataset for Task 2 --- Dating}},
  year      = {2021},
  publisher = {Zenodo},
  doi       = {10.5281/zenodo.4836687}
}