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It's easier than ever to de-censor videos

(www.jeffgeerling.com)
382 points DamonHD | 5 comments | 15 Apr 25 17:12 UTC | HN request time: 1.266s | source
1. wlesieutre ◴[15 Apr 25 20:12 UTC] No.43697826[source]▶
> If I hadn't moved around my Finder window in the video, I don't think it would've worked. You might get a couple letters right, but it would be very low confidence.

> Moving forward, if I do have sensitive data to hide, I'll place a pure-color mask over the area, instead of a blur or pixelation effect.

Alternately - don't pixelate on a stationary grid when the window moves.

If you want it to look nicer than a color box but without giving away all the extra info when data moves between pixels, pixelate it once and overlay with a static screenshot of that.

For bonus points, you could automate scrambling the pixelation with fake-but-real-looking pixelation. Would be nice if video editing tools had that built in for censoring, knowing that pixelation doesn't work but people will keep thinking it does.

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2. geerlingguy ◴[15 Apr 25 20:15 UTC] No.43697858[source]▶
That's another good way to do it.

I wonder if it might be good for the blur/censor tools (like on YouTube's editor even) to do an average color match and then add in some random noise to the area that's selected...

Would definitely save people from some hassle.

replies(1): >>43698228 #
3. wlesieutre ◴[15 Apr 25 20:51 UTC] No.43698228[source]▶
The part that might take some work is matching the motion correctly, with a pixelated area or blacked out rectangle it doesn't matter if it's exactly sized or moving pixel perfectly with the window. I haven't done any video editing in 20 years, so maybe that's not very difficult today?

That moving pixelation look is definitely cooler though. If you wanted to keep it without leaking data you could do the motion tracked screenshot step first (not pixelated, but text all replaced by lorem ipsum or similar) and then run the pixelation over top of that.

If any of you nerds reading this are into video editing, please steal this idea and automate it.

4. IshKebab ◴[15 Apr 25 21:24 UTC] No.43698564[source]▶
Yeah this scenario is purposefully chosen specifically to make this attack possible. It's basically irrelevant in the real world.
replies(1): >>43698782 #
5. geerlingguy ◴[15 Apr 25 21:45 UTC] No.43698782[source]▶
Someone's already emailed me the depixelated version of the paper I'm holding in the video attached to this blog post.