Benchmarks three preview pipelines across all sample documents:
- BMP → AVIF (via pyvips)
- PNG → AVIF (via pyvips) — selected for production
- PNG only (no compression)
Results confirm PNG → AVIF as the optimal path:
- ~30 ms AVIF encode overhead
- 2.1× size reduction vs raw PNG
- Slightly faster than BMP → AVIF
