This project includes a simple Transformer for Alfresco from PDF to OCRd PDF to be used with ACS Community 7.0+
OCR Transformation is performed by ocrmypdf, a wrapper of Tesseract that includes additional features in order to improve the accuracy of the process.
The Transformer ats-transformer-ocr uses the new Alfresco Local Transform API, that allows to register a Spring Boot Application as a local transformation service.
The folder embed-metadata-action includes an Alfresco Repository Addon that enables the action embed-metadata in Folder Rule feature.
Building the Alfresco OCR Transformer Docker Image is required before running the Docker Compose template provided.
$ cd ats-transformer-ocr
$ mvn clean package
Maven will create a Docker Image named alfresco/tengine-ocr:latest
$ docker run -p 8090:8090 alfresco/tengine-ocr:latest
A sample web page has been created in order to test the transformer is working:
Before deploying Alfresco OCR Transformer, embed-metadata-action Repository Addon should be built.
$ cd embed-metadata-action
$ mvn clean package
$ ls target/embed-metadata-action-1.0.0.jar
target/embed-metadata-action-1.0.0.jar
Alternatively embed-metadata-action-1.0.0.jar can be download from Releases
Use some of the available alternatives to deploy embed-metadata-action-1.0.0.jar in alfresco service, like adding the JAR to alfresco/modules/jar folder when using Alfresco Docker Installer tool.
Review that the following configuration is applied to docker-compose.yml file.
services:
alfresco:
environment:
JAVA_OPTS : "
-DlocalTransform.core-aio.url=http://transform-core-aio:8090/
-DlocalTransform.ocr.url=http://transform-ocr:8090/
"
transform-core-aio:
image: alfresco/alfresco-transform-core-aio:2.3.10
mem_limit: 1536m
environment:
JAVA_OPTS: " -XX:MinRAMPercentage=50 -XX:MaxRAMPercentage=80"
transform-ocr:
image: alfresco/tengine-ocr:latest
mem_limit: 1536m
environment:
JAVA_OPTS: " -XX:MinRAMPercentage=50 -XX:MaxRAMPercentage=80"
Remember that you need to build Docker Image for
alfresco/tengine-ocrbefore running this composition
Start ACS Stack from folder containing docker-compose.yml file.
$ docker-compose up --build --force-recreate
Use your browser to access to Alfresco Share App (by default available in http://localhost:8080/share/)
Create a folder and add following rule (Manage Rules folder option):
- When: Items are created or enter this folder
- If all criteria are met: Mimetype is 'Adobe PDF Document'
- Perform Action: Embed properties as metadata in content
To limit the amount of parallel OCR processing threads, use the Run rule in background checkbox.
From that point, every PDF File uploaded to the folder will be OCRd. Original version for the PDF file will remain as 1.0 version, while the one with text layer on it will be labeled as 1.1 version.
By default, Alfresco OCR Transformer is providing following ocrmypdf configuration.
# Executable command for ocrmypdf program
ocrmypdf.path=ocrmypdf
# Arguments for ocrmypdf invocation
ocrmypdf.arguments=--skip-text
Configuration can be changed by using Docker environment variables from command line.
$ docker run -p 8090:8090 -e OCRMYPDF_ARGUMENTS='--skip-text -l eng' alfresco/tengine-ocr:latest
Or with the equivalent notation in docker-compose.yml
transform-ocr:
image: alfresco/tengine-ocr:latest
mem_limit: 1536m
environment:
JAVA_OPTS: "-XX:MinRAMPercentage=50 -XX:MaxRAMPercentage=80"
OCRMYPDF_ARGUMENTS: "--skip-text -l eng"