https://github.com/OCR4all/ocr4all-backend.git# ocr4all-backend Master repository containing all required submodules to get the new OCR4all backend (still WIP) up and running

Contained submodules

• ocr4all-app-communication
• ocr4all-app-spi
• ocr4all-app-persistence
• ocr4all-app-ocrd-communication
• ocr4all-app-ocrd-spi
• ocr4all-app
• ocr4all-app-ocrd-msa

Getting started

Requirements

• git
• Java 17
• mvn
• docker compose
• bash (optional)

Download

Clone this repository recursively.

git clone --recurse-submodules --remote-submodules https://github.com/OCR4all/ocr4all-backend.git

An SSH Public key connected with your GitHub-Account is required.

Build

To steps are required to build the application:

1. compile the libraries and package the jars: run the bash script ocr4all-build.sh with the argument build.
2. build docker images: run docker compose with the argument build. The file docker-env-dev gives an example of a common setup of a development environment which stores the application data in the user's home directory ${user.home}/ocr4all/dev.

Application

To start the application run docker compose with the argument up. The server HTTP port is set to 9090. As by build, the file docker-env-dev gives an example of a common setup of a development environment.

Defaults

The defaults for the application are defined in the file src/main/resources/application.yml of the projects ocr4all-app, ocr4all-app-calamari-msa and ocr4all-app-ocrd-msa. Several profiles are defined that can be used to control the behaviour of the application.

Security

Authentication/authorisation is activated in the server profile and deactivated in the desktop profile.

Authentication/authorisation is configured in the following files in the ocr4all/workspace/.ocr4all folder (see below for an example setup): users, passwords and groups. After authentication in the application with administrative rights, the API can be used to manage users, passwords and groups.

A default administrator user is created, if the application has the server and development profile enabled and/or the application property ocr4all.application.security.administrator.create is set to true and no administrator user exists. The login credentials are

• username: admin
• password: ocr4all

Example: rights management setup

• File user admin:active::Administrator user
• File password (password ocr4all) admin:{bcrypt}$2a$10$rqYn8YjNLzegNMYZVFtvAuwAZBWFgZQ9bprHhjhHnk3oGUPdEPkYq
• File group admin:active:admin:Administrator group

Using ocr-d processors

Install models in ocr4all/opt/ocr-d/resources (see ocr-d resource list)

• Calamari recognize download desired models in subfolder ocrd-calamari-recognize
• Tesserocr recognize download desired models in subfolder ocrd-tesserocr-recognize

API

API documentation

The Swagger UI for the API documentation can be accessed under http://localhost:9090/api/doc/swagger-ui/index.html.

Example

An example of using the API.

instance
Method: GET
URL: http://localhost:9090/api/v1.0/instance

if authentication/authorization is activated, then login - for further communication, use the bearer token from the authorization KEY from the header or the token from the response body
Method: POST
URL: http://localhost:9090/api/v1.0/login
Body:
{
    "username": "admin",
	"password": "ocr4all"
}

create project
Method: GET
URL: http://localhost:9090/api/v1.0/project/create?id=project_01

Add in exchange folder the images
folder: ocr4all/exchange/project_01/images

See running/done jobs
Method: GET
URL: http://localhost:9090/api/v1.0/job/scheduler/snapshot/administration

Import the images in the project from exchange folder
Method: POST
URL: http://localhost:9090/api/v1.0/spi/import/schedule/project_01
Body:
{
"id": "de.uniwuerzburg.zpd.ocr4all.application.core.spi.imp.provider.ImageImport",
"strings": [
{"argument": "source-folder", "value": "images"}
],
"selects": [
{"argument": "image-formats", "values": ["tif"]}
]
}

Create a sandbox
Method: GET
URL: http://localhost:9090/api/v1.0/sandbox/create/project_01?id=sandbox_01

Launch the sandbox
Method: POST
URL: http://localhost:9090/api/v1.0/spi/launcher/schedule/project_01/sandbox_01
Body:
{
"id": "de.uniwuerzburg.zpd.ocr4all.application.core.spi.launcher.provider.SandboxLauncher",
"images": [
{"argument": "images", "values": [1,2,3,4,5,6]}
],
"label": "launcher default with images",
"description": "description launcher default with images"
}

• Using ocr-d processors

preprocessing: Binarize
Method: POST
URL: http://localhost:9090/api/v1.0/spi/preprocessing/schedule/project_01/sandbox_01
Body:
{
"id": "de.uniwuerzburg.zpd.ocr4all.application.ocrd.spi.msa.preprocessing.MsaCISOcropyBinarize",
"parent-snapshot": {"track": []},
"label": "cis binarize default",
"description": "ocr-d cis ocropy binarize default"
}

olr: Segment region
Method: POST
URL: http://localhost:9090/api/v1.0/spi/olr/schedule/project_01/sandbox_01
Body:
{
"id": "de.uniwuerzburg.zpd.ocr4all.application.ocrd.spi.msa.olr.MsaTesserocrSegmentRegion",
"parent-snapshot": {"track": [1]},
"label": "tesserocr segment region default",
"description": "ocr-d tesserocr segment region default"
}

olr: Segment line

Method: POST
URL: http://localhost:9090/api/v1.0/spi/olr/schedule/project_01/sandbox_01
Body:
{
"id": "de.uniwuerzburg.zpd.ocr4all.application.ocrd.spi.msa.olr.MsaTesserocrSegmentLine",
"parent-snapshot": {"track": [1,1]},
"label": "tesserocr segment line default",
"description": "ocr-d tesserocr segment line default"
}

ocr: Calamari recognize
Method: POST
URL: http://localhost:9090/api/v1.0/spi/ocr/schedule/project_01/sandbox_01
Body:
{
"id": "de.uniwuerzburg.zpd.ocr4all.application.ocrd.spi.msa.ocr.MsaCalamariRecognize",
"selects": [ {"argument": "checkpoint_dir", "values": ["fraktur_historical"]} ],
"parent-snapshot": {"track": [1,1,1]},
"label": "Calamari model",
"description": "ocr-d Calamari model fraktur_historical"
}

ocr: Tesserocr recognize
Method: POST
URL: http://localhost:9090/api/v1.0/spi/ocr/schedule/project_01/sandbox_01
Body:
{
"id": "de.uniwuerzburg.zpd.ocr4all.application.ocrd.spi.msa.ocr.MsaTesserocrRecognize",
"selects": [{"argument": "model", "values": ["deu", "frk"]}],
"parent-snapshot": {"track": [1,1,1]},
"label": "Tesserocr models",
"description": "ocr-d Tesserocr models deu + frk"
}

Results will be available in the following directories:

• Calamari recognize ocr4all/workspace/projects/project_01/sandboxes/sandbox_01/snapshots/derived/1/derived/1/derived/1/derived/1/sandbox
• Tesserocr recognize ocr4all/workspace/projects/project_01/sandboxes/sandbox_01/snapshots/derived/1/derived/1/derived/1/derived/2/sandbox