ocrd-tesserocr 0.6.0

Tesserocr bindings

ocrd_tesserocr

Crop, deskew, segment into regions / lines / words, or recognize with tesserocr

Introduction

This offers OCR-D compliant workspace processors for (much of) the functionality of Tesseract via its Python API wrapper tesserocr . (Each processor is a step in the OCR-D functional model, and can be replaced with an alternative implementation. Data is represented within METS/PAGE.)

This includes image preprocessing (cropping, binarization, deskewing), layout analysis (region, line, word segmentation) and OCR proper. Most processors can operate on different levels of the PAGE hierarchy, depending on the workflow configuration. Image results are referenced (read and written) via AlternativeImage, text results via TextEquiv, deskewing via @orientation, cropping via Border and segmentation via Region / TextLine / Word elements with Coords/@points.

Installation

Required ubuntu packages:

• Tesseract headers (libtesseract-dev)
• Some tesseract language models (tesseract-ocr-{eng,deu,frk,...} or script models (tesseract-ocr-script-{latn,frak,...})
• Leptonica headers (libleptonica-dev)

From PyPI

This is the best option if you want to use the stable, released version.

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NOTE

ocrd_tesserocr requires Tesseract >= 4.1.0. The Tesseract packages bundled with Ubuntu < 19.10 are too old. If you are on Ubuntu 18.04 LTS, please enable Alexander Pozdnyakov PPA which has up-to-date builds of Tesseract and its dependencies:

sudo add-apt-repository ppa:alex-p/tesseract-ocr
sudo apt-get update

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sudo apt-get install git python3 python3-pip libtesseract-dev libleptonica-dev tesseract-ocr-eng tesseract-ocr wget
pip install ocrd_tesserocr

With docker

This is the best option if you want to run the software in a container.

You need to have Docker

docker pull ocrd/tesserocr

From git

This is the best option if you want to change the source code or install the latest, unpublished changes.

We strongly recommend to use venv.

git clone https://github.com/OCR-D/ocrd_tesserocr
cd ocrd_tesserocr
make deps-ubuntu # or manually with apt-get
make deps        # or pip install -r requirements
make install     # or pip install .

Usage

See docstrings and in the individual processors and ocrd-tool.json descriptions.

Available processors are:

• ocrd-tesserocr-crop
• ocrd-tesserocr-deskew
• ocrd-tesserocr-binarize
• ocrd-tesserocr-segment-region
• ocrd-tesserocr-segment-line
• ocrd-tesserocr-segment-word
• ocrd-tesserocr-recognize

Testing

To run with docker:

docker run ocrd/tesserocr ocrd-tesserocrd-crop ...

Testing

make test

This downloads some test data from https://github.com/OCR-D/assets under repo/assets, and runs some basic test of the Python API as well as the CLIs.

Set PYTEST_ARGS="-s --verbose" to see log output (-s) and individual test results (--verbose).

Development

Latest changes that require pre-release of ocrd >= 2.0.0 are kept in branch edge.