impact-print-v2-train-pages

The 298 historical Polish print page images referenced by the train split of PiotrSty/impact-print-v2 (22 train works), fetched from the IMPACT dLibra server and made locally available for training. The line-level ground truth (1 987 transcribed regions) stays in the impact-print-v2 metadata (train_regions.jsonl); this repo carries the page images bound to it.

Provenance and license

• Source ground truth: IMPACT Polish ground truth via impactcentre/groundtruth-pol (pinned commit 0a5a88863f104d8ab26b22b7c0a32c58dd3c5f15), PSNC, dLibra ribes-80.man.poznan.pl.
• License: CC BY 3.0 — inherited from the pinned PiotrSty/impact-psnc-polish-ocr subset and its sources. Attribution:

  IMPACT Polish ground truth, Poznan Supercomputing and Networking Center (PSNC), via the IMPACT Centre of Competence, CC BY 3.0.

• The 65 pages shared with the psnc subset are byte-identical copies of its JPEGs (their image_sha256 preserved). The remaining 233 pages were downloaded as source TIFFs and converted following the psnc convention: RGB JPEG, quality 95, no chroma subsampling.

Integrity and method

• edition_id = document_id + 270919 (the dLibra URL formula used by the original psnc builder; verified again during this fetch).
• The dLibra TLS certificate is currently expired; downloads used an unverified TLS context — the same workaround as the original psnc builder. Integrity is enforced by sha256: every fetched TIFF matched the checksum recorded in the impact-print-v2 region metadata while the certificate was still valid (all 233 pages verified; see ACQUISITION_AUDIT.json).
• manifest.jsonl binds every image to its source URL, document/edition ids, image sha256 and the v2 metadata sha. checksums.json covers the package.

Split guard

Only the 22 train works of impact-print-v2 are present. The frozen validation and test works (Choragiew, Relacja_koronacji, Sławne Wiktorie, Wiesc; NA2, Nowiny z Rakuz, Powodzenia) are deliberately absent and must not be added to any training package.

Files

• images/ — 298 page JPEGs named <work>__<document_id>.jpg.
• manifest.jsonl — one row per page: source, ids, hashes.
• ACQUISITION_AUDIT.json — method validation, counts, TLS note, license.
• checksums.json — package integrity (sha256 of every file).
• fetch_impact_v2_train_pages.py — deterministic re-fetch script.

Limitations

• These are format-converted derivatives (JPEG), not the original TIFF scans.
• Historical spelling and glyphs are preserved in the ground-truth texts; the texts themselves live in the impact-print-v2 metadata, not here.