This extension enhances Greenstone3's ability to process with images using
the Google Vision API.  This includes OCRing of text in documents, OCRing
of text in photos, and labelling photos.  Presentation of the OCR'd results
in enhanced through the Mirador annotation viewer.

At build-time, collections can tap into these capabilities using the plugins:

    GoogleVisionImagePlugin.pm
    GoogleVisionPagedImagePlugin.pm

At runtime 


#---
# Setup
#---

Run:

  ./PREPARE-PYTHON3.sh

  # TLDR
  cd packages && ./COMPILE-AND-INSTALL.sh && cd ..
  # See packages/README.txt for more details

  # TLDR
  cd src && ./PREPARE.sh && ./COMPILE.sh && ./INSTALL.sh && cd ..
  # See src/README.txt for more details


Review:
    ant-start-settings.bash.in

Copy to:
    ant-start-settings.bash

And edit accordingly.  This controls how Greenstone accesses the SimpleAnnotationServer.


To enable the Google Vision API, set up a key etc, see:

    https://cloud.google.com/vision/docs/setup


When you create a key, your browsesr downloads a JSON version of the key.

    
#---
# Using the Extension: Build-time
#---

The extension provides the GoogleVisionImagePlugin, for use in collections.

Example use of the plugin:

    <plugin name="GoogleVisionImagePlugin">
      <option name="-enable_document_ocr"/>
      <option name="-enable_image_labelling"/>
    </plugin>

The plugin currently has a hard-wired filename for the Google
service key.  This need's to be in the collection's 'etc'
directory as follows:

    etc/my-google-service-account-key.json


For the 'atea-storage' Google Cloud Project, for example, a redacted version of
the JSON key file looks like:

{
  "type": "service_account",
  "project_id": "atea-storage",
  "private_key_id": "7bc843de4257da515193eaa5b60468fcab5b3948",
  "private_key": "-----BEGIN PRIVATE KEY-----\n???????.........??????=\n-----END PRIVATE KEY-----\n",
  "client_email": "service-account@atea-storage.iam.gserviceaccount.com",
  "client_id": "123???...????",
  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  "token_uri": "https://oauth2.googleapis.com/token",
  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/service-account%40atea-storage.iam.gserviceaccount.com"
}


#---
# Using the Extension: Runtime
#---


Check out the 'intermuse' site and interface

Build the intermuse-demo collection

Visit the built collection in your browser