Make it easy for users to find, organize, and surface the best photos from large collections quickly and accurately.
Structured Data: Use schema markup for images, especially for products or recipes, to earn rich results in image search.
For personal or professional archives, a "better" index ensures your collection remains searchable: The Pyramid System index of photo better
The Verdict: DigiKam is a hidden gem. It is designed specifically to handle enormous datasets. Its facial recognition engine is surprisingly accurate, automatically indexing your photos by the people in them.
Do use a lightweight gallery script that: Feature: Enhanced Photo Indexing & Best-Photo Surfacing Goal
When you rate or tag a RAW photo in Bridge or Lightroom, it creates a tiny .xmp file that sits next to your RAW file.
When deciding which photos are "better" to include in your index, use these critique points: Adobe Lightroom Google Photos Apple Photos Flickr PhotoIndex
Effective Image SEO Tips: Enhance Site Performance - D-Libro