dinglehopper

dinglehopper is an OCR evaluation tool and reads ALTO, PAGE and text files. It compares a ground truth (GT) document page with a OCR result page to compute metrics and a word/character differences report.

Goals

• Useful
  • As a UI tool
  • For an automated evaluation
  • As a library
• Unicode support

Installation

It's best to use pip, e.g.:

sudo pip install .

Usage

Usage: dinglehopper [OPTIONS] GT OCR [REPORT_PREFIX]

  Compare the PAGE/ALTO/text document GT against the document OCR.

  The files GT and OCR are usually a ground truth document and the result of
  an OCR software, but you may use dinglehopper to compare two OCR results.
  In that case, use --no-metrics to disable the then meaningless metrics and
  also change the color scheme from green/red to blue.

  The comparison report will be written to $REPORT_PREFIX.{html,json}, where
  $REPORT_PREFIX defaults to "report".

Options:
  --metrics / --no-metrics  Enable/disable metrics and green/red
  --help                    Show this message and exit.

For example:

dinglehopper some-document.gt.page.xml some-document.ocr.alto.xml

This generates report.html and report.json.

As a OCR-D processor:

ocrd-dinglehopper -I OCR-D-GT-PAGE,OCR-D-OCR-TESS -O OCR-D-OCR-TESS-EVAL

This generates HTML and JSON reports in the OCR-D-OCR-TESS-EVAL filegroup.

You may also want to disable metrics and the green-red color scheme by parameter:

ocrd-dinglehopper -I ABBYY-FULLTEXT,OCR-D-OCR-CALAMARI -O OCR-D-OCR-COMPARE-ABBYY-CALAMARI -p '{"metrics": false}'

Testing

Use pytest to run the tests in the tests directory:

virtualenv -p /usr/bin/python3 venv
. venv/bin/activate
pip install -r requirements.txt
pip install pytest
pytest