Yep, I store each hash in the DB. The ruby gem has a mechanism to test similarity to your existing hashes with a threshold so small edits still match. It's su

Yep, I store each hash in the DB. The ruby gem has a mechanism to test similarity to your existing hashes with a threshold so small edits still match. It's surprisingly fast too, checking against every existing hash doesn't noticeably slow down the upload. I think it's a bitwise compare, but admittedly I set that up a long time ago so I'm foggy on the details. Originally I added it because I wanted a way to automatically find the full quality image from my archive and replace the aggressively scaled down versions I used to use. Back in 2003 100KB was considered pretty big for a photo, but now it looks like garbage. I never found time to finish that part of it.