Image Filter

Hi guys I have a specific question about the images in my site. My site is a social network site for models and photographers. Everybody can upload own portfolio, bio, ect. I want to use an ADULT Filters for the images.

I want to give my users this 2 options:

  1. On the uploading process, every user can mark his photo as containing nudity. Probably with additional check box for example.
  2. I need this photo to be invisible for the other users, unless they decide to view it switching off the safety mode of the site.