AFAIK Discord's NSFW filter is not a perceptual hash nor uses the NCMEC database (although that might indeed be in the pipeline elsewhere) but instead uses a ML

AFAIK Discord's NSFW filter is not a perceptual hash nor uses the NCMEC database (although that might indeed be in the pipeline elsewhere) but instead uses a ML classifier (I'm certain it doesn't use perceptual hashes as Discord doesn't have a catalogue of NSFW image hashes to compare against). I've guessed it's either open_nsfw[0] or Google's Cloud Vision since the rest of Discord's infrastructure uses Google Cloud VMs. There's a web demo available of this api[1], Discord probably pulls the safe search classifications for determining NSFW. 0: https://github.com/yahoo/open_nsfw https://github.com/yahoo/open_nsfw 1: https://cloud.google.com/vision#section-2 https://cloud.google.com/vision#section-2