hOCR-to-ALTO

Convert between Tesseract hOCR and ALTO XML 2.0/2.1/3/4 using XSL stylesheets

The XSLT scripts use XSLT 2.0 features - so a XSLT 2.0 capable transformer is required - ie. Saxon

Running the conversion using Saxon-HE command line - example converting ALTO to hOCR:

1. Unpack the Saxon distribution into the saxon subdir

2. Place your input file(s) into the _input subdir

3. Run:

    java -jar "saxon/saxon-he-12.7.jar" -s:_input/input-alto.xml -xsl:alto__hocr.xsl -o:_output/output-hocr.xml
   

   Or use the run-saxon script from bash:

   $ /.run-saxon input-alto.xml alto__hocr.xsl output-hocr.xml
   

4. Check the _output dir.

See ocr-fileformat for an interface to using these stylesheets.

hOCR-spec https://github.com/kba/hocr-spec

File naming scheme: sourceFormatVersion__targetFormatVersion.xsl

CONTENTS

• Convert ALTO to hOCR
  • alto__hocr.xsl
• Convert hOCR to ALTO
  • hocr__alto.xsl
  • hocr__alto4.xsl
  • hocr__alto3.xsl
  • hocr__alto2.1.xsl
  • hocr__alto2.0.xsl
• Convert ALTO to plain text
  • alto__text.xsl
• Convert hOCR to plain text
  • hocr__text.xsl
• Language codes
  • codes_lookup.xml - generated with https://github.com/filak/iso-language-codes