Deployment

Deploy the OCR REST API service using Docker for production environments. This guide covers Docker deployment, docker-compose orchestration, image variant selection, and security best practices for running Tesseract and PaddleOCR text recognition services.

The OCR service is available as pre-built Docker images on Docker Hub, optimized for different use cases and deployment scenarios.

Docker Hub Repository: https://hub.docker.com/r/gunthercox/ocr-service

Image Variants

The service provides three Docker image variants optimized for different use cases:

Combined (default) - Both engines available

Use when you need flexibility to switch between OCR engines per request.

  • Tags: latest, 1.0.0, 1.0

  • Python version: 3.12

  • Includes: Tesseract + PaddleOCR

  • Size: Largest (includes 140+ Tesseract language packs)

  • Available engines: Both tesseract and paddleocr

Tesseract only - Document OCR

Optimized for standard document OCR workloads.

  • Tags: latest-tesseract, 1.0.0-tesseract, 1.0-tesseract

  • Python version: 3.12

  • Includes: Tesseract with all language packs

  • Size: Medium

  • Available engines: Only tesseract

PaddleOCR only - Modern OCR with latest Python

Best for rotated/multi-directional text or size-constrained environments.

  • Tags: latest-paddleocr, 1.0.0-paddleocr, 1.0-paddleocr

  • Python version: 3.13

  • Includes: PaddleOCR only

  • Size: Smallest

  • Available engines: Only paddleocr

Important: Engine-specific images will return a 400 error if you request an unavailable engine. For example:

# This will fail with Tesseract-only image
curl -X POST -F "image=@photo.png" -F "engine=paddleocr" http://localhost:5000/

The error response will indicate which engines are available in the deployed image variant.

Deployment using docker-compose

For production environments, it is recommended to use the official Docker image from Docker Hub. Below is an example docker-compose.yml for deploying the OCR service in production:

Combined variant (default, both engines):

docker-compose.yml
 services:
   ocr-service:
     image: gunthercox/ocr-service:latest
     ports:
       - "5000:5000"
     restart: unless-stopped

Tesseract-only variant (smaller, document OCR):

docker-compose.yml
 services:
   ocr-service:
     image: gunthercox/ocr-service:latest-tesseract
     ports:
       - "5000:5000"
     restart: unless-stopped

PaddleOCR-only variant (smallest, Python 3.13):

docker-compose.yml
 services:
   ocr-service:
     image: gunthercox/ocr-service:latest-paddleocr
     ports:
       - "5000:5000"
     restart: unless-stopped

You can also pin to a specific version for more predictable deployments:

docker-compose.yml
 services:
   ocr-service:
     image: gunthercox/ocr-service:1.1.2-paddleocr
     ports:
       - "5000:5000"
     restart: unless-stopped

To run the service using docker-compose, run the following command in the directory containing your docker-compose.yml file:

docker compose up -d

  • The service will be available at http://localhost:5000/ by default.

Security Considerations

  • For production, consider using a reverse proxy (e.g., Nginx) in front of the service for SSL termination and additional security.

  • Monitor and update the image regularly to receive security and feature updates.

  • Validate and sanitize all uploaded files to prevent malicious input.

  • Limit accepted file types to images only.

  • Consider rate limiting and authentication for production deployments.

Additional Notes: