Reply to post: Re: Why...

Facebook's send-us-your-nudes service is coming to UK, America

Anonymous Noel Coward

Re: Why...

Doubt that would work, since you could just change one pixel and the hash would change. Meaning you could have 2,000 separate hashes for the same image.

For example, services that flag child pornography when it's uploaded use a special software (PhotoDNA) which converts the image to grayscale, then breaks it down into a grid and calculates a number per grid until they wind up with something like 1000,481,0,0,251..., meaning that modifying the image is pointless.

People would be better off getting the numerical sum of their nudes with that.

But the problem with that is, regular people aren't allowed access to that software unless they're a LEA or popular service like Facebook. (Which sucks, as I have a large anime artwork collection I'd love to sort through far more easily to remove duplicates.)

POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon

Biting the hand that feeds IT © 1998–2019