Kraken 7 requires pyvips (optional dep) for -f pdf mode.
Added libvips42 system package and pyvips Python package.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
torchvision installed from PyPI expects CUDA torch operator
registrations. Installing from the CPU whl index ensures torchvision
matches the CPU-only torch build. Fixes 'torchvision::nms does not
exist' RuntimeError on startup.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Python microservice (ocr-service/):
- FastAPI app with /ocr and /health endpoints
- Surya engine: transformer-based OCR for typewritten/modern handwriting
- Kraken engine: historical HTR for Kurrent/Suetterlin with
pure-Python polygon-to-quad approximation (gift wrapping + rotating calipers)
- Eager model loading at startup via lifespan context manager
- PDF download via httpx, page rendering via pypdfium2 at 300 DPI
Java RestClientOcrClient:
- Implements OcrClient + OcrHealthClient interfaces
- Calls Python service via Spring RestClient
- Health check with graceful fallback
Docker Compose:
- New ocr-service container (mem_limit 6g, no host ports)
- Health check with start_period 60s for model loading
- ocr_models volume for Kraken model files
- Backend depends on ocr-service health
Refs #226, #227
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
