cedulauy-mrz-scan

Read the MRZ of Uruguayan identity cards (cédula de identidad) from a webcam or a photo.

Alpha. The API may change between releases.

Install

The package needs Python 3.10+ and the Tesseract OCR engine, which is a separate program.

1. Install Tesseract

Any language data works: the MRZ model (OCR-B) ships with this package, so no tessdata setup is needed. On Windows the default install folder (C:\Program Files\Tesseract-OCR) is found even if it is not on PATH.

Check it with:

tesseract --version

On a minimal Linux install (server, container), OpenCV also needs the OpenGL and GLib libraries: libgl1 libglib2.0-0 (Debian/Ubuntu), mesa-libGL glib2 (Fedora), mesa glib2 (Arch).

2. Install the package

uv add cedulauy-mrz-scan
# or
pip install cedulauy-mrz-scan

Usage

Point a webcam at the back of the card:

cedulauy-mrz-scan --camera 0

A window shows a card-shaped guide and tells you how to hold the card: closer, straighter, still. When it is well placed, two pictures are taken and the MRZ is printed. Press q or Esc to quit.

From a photo or scan:

cedulauy-mrz-scan --image card.jpg
cedulauy-mrz-scan --image card.jpg -o mrz.txt

From Python:

from cedulauy_mrz_scan import scan_camera, scan_image

mrz = scan_camera(0)          # None if the user quits
mrz = scan_image("card.jpg")  # raises ValueError if unreadable

The result is the raw TD1 MRZ as one 90-character string (3 lines of 30). read_mrz(image) reads an already cropped image of the code and returns (mrz or None, lines read).

Features

• Guided capture: finds the MRZ lines in the live image and tells the user how to place the card, before any OCR runs.
• Verified: a read is only returned if it passes the check digits.
• Double capture: two pictures must give the same read, which also covers the name (check digits don't).
• OCR-B model: bundled, trained for MRZ text; the default English model misreads < as K.
• Offline: everything runs locally, nothing is sent anywhere.
• Spanish / English: on-screen texts follow the system language.

Tips

• Even light without reflections matters most; a shiny card under a ceiling lamp is the usual failure.
• Hold the card steady once the bar starts filling; moving restarts it.

Development

uv sync            # create .venv and install dev dependencies
uv run pytest      # run tests
uv run ruff check  # lint
uv build           # build sdist and wheel into dist/

License

GPL-3.0-or-later. The bundled OCR-B model (tessdata/mrz.traineddata) is from DoubangoTelecom/tesseractMRZ, BSD-3-Clause.