pylopdf-ocr-models 0.1.0

PP-OCRv6 small RTen models for pylopdf's optional offline OCR engine

pylopdf-ocr-models

A data-only package containing the PP-OCRv6 small detector, recognizer, and multilingual character dictionary used by pylopdf. The models run locally through pylopdf's pure-Rust RTen backend; OCR does not require a system executable, ONNX Runtime, an ONNX parser at runtime, or network access.

Install it through the main package extra:

pip install "pylopdf[ocr]"

The small PP-OCRv6 tier is intended for mobile and desktop use. Its unified model supports 50 languages, including Japanese, Simplified Chinese, Traditional Chinese, and English.

Bundled artifacts

File	Purpose	SHA-256
PP-OCRv6_det_small.rten	Multilingual text detection	57c5778be784d7aace438a4ea1926864a7b5fd3d49c8e577799f8a83e8dcb022
PP-OCRv6_rec_small.rten	Multilingual text recognition	b6eef947901c5ff0bf6ee62d8b46f58b1423666f0ae0c87b2f42127502925f8f
ppocrv6_dict.txt	Recognition character dictionary	b5f2bfe2bdd9448429e3e82b51c789775d9b42f2403d082b00662eb77e401c5d

The installed package also includes these values in SHA256SUMS. Release CI builds the wheel and sdist twice and requires byte-identical output. It then installs both formats into isolated environments, verifies distribution metadata and license files, and streams each installed artifact through SHA-256 before publishing.

The source ONNX artifacts and dictionary are the PP-OCRv6 small files listed in RapidOCR's pinned model manifest and downloaded from its versioned v3.9.2 model repository. They originate from PaddleOCR; RapidOCR converted and distributes the ONNX forms.

Source	URL	SHA-256
Detector ONNX	PP-OCRv6_det_small.onnx	090f04abcd9d9a7498bc4ebf677e4cb9bdce1fe4197ddb7e529f1ef44e1ff94f
Recognizer ONNX	PP-OCRv6_rec_small.onnx	6f327246b50388f3c176ae304bd95767ea6dc0c9ae92153ef8cbe210b3c14884
Dictionary	ppocrv6_dict.txt	b5f2bfe2bdd9448429e3e82b51c789775d9b42f2403d082b00662eb77e401c5d

Reproducing the RTen conversion

After downloading and verifying the source files above, reproduce the bundled model data from the repository root with:

uvx --from rten-convert==0.22.0 rten-convert \
  --no-infer-shapes PP-OCRv6_det_small.onnx PP-OCRv6_det_small.rten
uvx --from rten-convert==0.22.0 rten-convert \
  --no-infer-shapes PP-OCRv6_rec_small.onnx PP-OCRv6_rec_small.rten

rten-convert embeds each source ONNX SHA-256 in the RTen file. Conversion is deterministic: repeating the commands produces the artifact hashes in the first table. Numerical outputs were also checked against the ONNX models before packaging. The character dictionary remains a separate input because RTen's conversion format does not preserve the ONNX recognizer's custom character metadata.

Model copyright is held by Baidu. PaddleOCR and RapidOCR are licensed under Apache License 2.0. See LICENSE and NOTICE.