A script that goes through a lemmy pict-rs object storage and tries to prevent illegal or unethical content - GitHub - Haidra-Org/lemmy-safety: A script that goes through a lemmy pict-rs object sto...
I noticed a bit of panic around here lately and as I have had to continuously fight against pedos for the past year, I have developed tools to help me detect and prevent this content.
As luck would have it, we recently published one of our anti-csam checker tool as a python library that anyone can use. So I thought I could use this to help lemmy admins feel a bit more safe.
The tool can either go through all your images via your object storage and delete all CSAM, or it canrun continuously and scan and delete all new images as well. Suggested option is to run it using --all once, and then run it as a daemon and leave it running.
Better options would be to be able to retrieve exact images uploaded via lemmy/pict-rs api but we’re not there quite yet.
Let me know if you have any issue or improvements.
EDIT: Just to clarify, you should run this on your desktop PC with a GPU, not on your lemmy server!
It’s more than just basic hash matching because it has to catch content even if it’s been resized, cropped, reduced in quality (lower JPEG quality with more artifacts), colour balance change, etc.
There’s better approaches than hashing. For comparing images I am calculating “distance” in tensors between them. This can match even when compression artifacts are involved or the images are slightly altered.
Microsoft’s PhotoDNA is probably the most well-known. Every major service that has user-generated content uses it. Last I checked, it wasn’t open-source. It was built for detecting CSAM, but it’s really just a general-purpose similarity hashing algorithm.
You are not logged in. However you can subscribe from another Fediverse account, for example Lemmy or Mastodon. To do this, paste the following into the search field of your instance: !selfhosted@lemmy.world
A place to share alternatives to popular online services that can be self-hosted without giving up privacy or locking you into a service you don’t control.
Rules:
Be civil: we’re here to support and learn from one another. Insults won’t be tolerated. Flame wars are frowned upon.
No spam posting.
Posts have to be centered around self-hosting. There are other communities for discussing hardware or home computing. If it’s not obvious why your post topic revolves around selfhosting, please include details to make it clear.
Don’t duplicate the full text of your blog or github here. Just post the link for folks to click.
Submission headline should match the article title (don’t cherry-pick information from the title to fit your agenda).
No trolling.
Resources:
selfh.st Newsletter and index of selfhosted software and apps
It’s more than just basic hash matching because it has to catch content even if it’s been resized, cropped, reduced in quality (lower JPEG quality with more artifacts), colour balance change, etc.
Ah, of course - that’s unfortunate, but thanks for the pointer.
Well, we have hashing algorithms that do exactly that, like phash for example.
Definitely. A lot of the good algorithms used by big services are proprietary though, unfortunately.
Can you point me to some of them? I’m quite interested in visual hashing.
There’s better approaches than hashing. For comparing images I am calculating “distance” in tensors between them. This can match even when compression artifacts are involved or the images are slightly altered.
Microsoft’s PhotoDNA is probably the most well-known. Every major service that has user-generated content uses it. Last I checked, it wasn’t open-source. It was built for detecting CSAM, but it’s really just a general-purpose similarity hashing algorithm.
Meta has some algorithms that are open-source: https://about.fb.com/news/2019/08/open-source-photo-video-matching/
Google has CSAI Match for hash-matching of videos and Google Content Safety API for classification of new content, but both are proprietary.