Ask HN:What desktop software do you use to Tag Photos automatically?

Is there a software to automatically tag photos on Windows without having to upload them to "tagging-as-a-service sites?

I've got over 20k images to tag. Doing it all manually is mind numbing and time consuming.

I've tried a bunch of software but they all suck. Photoshop's image organizer is lovely but doesn't tag photos automatically.

Suggestions would be really helpful.