Current build status:
CI Server: http://jenkins.discoverygarden.ca
- summary
- requirements
- installation
- configuration
- faq
Islandora OCR
This module acts a Toolkit for generating OCR and word coordinate information. At the moment it relies exclusively on Tesseract to generate this information.
Tesseract: http://code.google.com/p/tesseract-ocr/
ImageMagic: (Optional, Required for OCR preprocessing) http://www.imagemagick.org/
Tesseract:
Tesseract is an OCR engine that was developed at HP Labs between 1985 and 1995 it is currently being developed at Google. Recognized as one of the most accurate open source OCR engines available, Tesseract will read binary, grey, or colour images and output text.
A TIFF reader that will read uncompressed TIFF images is also included. Islandora Book Solution Pack currently uses Tesseract version 3.2, which can be obtained from the project home page. Lower versions are not supported.
http://code.google.com/p/tesseract-ocr/
Installation will differ depending on your operating system; please see the README Wiki for detailed instructions.
http://code.google.com/p/tesseract-ocr/wiki/ReadMe
Solr result highlighting:
To have Islandora viewers recognize Solr search results and highlight them one will need to configure Solr to index the HOCR in a particular fashion.
The field that the HOCR is stored in must have the following attributes: indexed="true" stored="true" termVectors="true" termPositions="true" termOffsets="true"
Each text node of each element in the HOCR datastream must be placed in order in a single value for the Solr field with all whitespace sub strings normalized to a single space.
Any objects that were previously ingested but require this functionality will need to be re-indexed.
Reference Implementation: https://github.com/discoverygarden/basic-solr-config/blob/modular/islandora_transforms/XML_text_nodes_to_solr.xslt
The Solr field for used for highlighting can be configured at admin/islandora/ocr.
Tesseract:
Tesseract provides many languages which can be downloaded from here:
http://code.google.com/p/tesseract-ocr/downloads/list
To install just unzip them in your tessdata directory, typically located:
/usr/local/share/tessdata
If you want to add your own langauges or train your Tesseract for your specific needs please review the documentation here:
http://code.google.com/p/tesseract-ocr/wiki/TrainingTesseract3
If you encounter any problems try the Tesseract FAQ.