Comments on: YouTube announces face blurring feature

By: ssam

ssam — Thu, 19 Jul 2012 14:14:00 +0000

yes. assuming that the authorities can’t get hold of the original, which you just uploaded to the youtube server.

By: millie fink

millie fink — Thu, 19 Jul 2012 13:44:00 +0000

Good on Google for acknowledging the legitimacy of activism (along with the identity of “activist”).

By: pnw29

pnw29 — Thu, 19 Jul 2012 12:48:00 +0000

There is a technology that blur and encrypt faces reversibly. www.engprivacy.com

By: Tynam

Tynam — Thu, 19 Jul 2012 09:00:00 +0000

You could probably design a blur scheme that encodes some of the original data on a backchannel. But it would be enormously hard to do, and to what end?

By their nature, blur algorithms tend to be one-way functions. Image manipulation has common ground with encryption, but they’re not at all the same thing.

By: Tynam

Tynam — Thu, 19 Jul 2012 08:56:00 +0000

(replying to Uthor): Not a problem in this case. It’s actually really difficult to make a blur filter which is reversible; even the most naive approach results in permanent data loss. Blurring, by it’s nature, deletes the detail that was originally there.

By: Tynam

Tynam — Thu, 19 Jul 2012 08:53:00 +0000

Ummm… there are parents with really good reasons not to broadcast their children’s faces. Adoptive parents of children from damaged homes, for example – often the worst thing that could possibly happen to such children is for their original family to find them.

On a more general level, you can make an ethical argument that it’s unwise to do anything irrevocable to someone else without informed adult consent. And putting footage online is irrevocable.

By: chaopoiesis

chaopoiesis — Thu, 19 Jul 2012 07:16:00 +0000

I just uploaded a face-blurred Hotel Mario Intro… no effect at all :(

By: Mr. Winka

Mr. Winka — Thu, 19 Jul 2012 05:03:00 +0000

Many assume blurring cannot be easily reversed. If it’s designed using a one-way function like hashing, then it wouldn’t be practical. However, if it’s designed like encryption and the key is maintained, then it could be reversed. I guess what I’m saying is that you should assume they have the key. If something’s not trustworthy, then why trust it?!

By: Uthor

Uthor — Thu, 19 Jul 2012 01:50:00 +0000

“It can be specific and predictable without being reversible.”

Yeah, I figure. I guess I’m just wondering if it is in this specific case. I’d assume Google’s engineers are smart enough to think of this, but to paraphrase Bruce Schnier, anyone can make a system they themselves cannot break.

By: That_Anonymous_Coward

That_Anonymous_Coward — Thu, 19 Jul 2012 01:29:00 +0000

Interpol can do it… anyone can…
http://boingboing.net/2007/10/08/untwirling-photo-of.html

By: oasisob1

oasisob1 — Wed, 18 Jul 2012 23:39:00 +0000

…said the guy who NEVER watched a movie, ever! “ENHANCE!”

By: inedible

inedible — Wed, 18 Jul 2012 22:01:00 +0000

That’s been done actually!

http://hackaday.com/2008/12/31/laughing-man-in-processing/

By: rrh

rrh — Wed, 18 Jul 2012 21:47:00 +0000

It can be specific and predictable without being reversible.

Blurring results in a loss of finer details. Unlike what CSI would have you believe, you can’t just “enhance” those details back into existence.

By: citizen

citizen — Wed, 18 Jul 2012 21:31:00 +0000

[Guess it wasn't me after all, this should be a reply to Uthor]

A blurred (or mosaicked) image carries less information than the original, there are a lot of potential sharp images that produce the same blurred output.

I suppose moving images complicate matters a bit. You might be able to wring some extra information from the image by analysing the way a region of the image shifts colour when the face being blurred shifts a few pixels. With real-life movement also involving possible changes in pitch, roll, yaw or distance of the face, I don’t see this working very well.

What you’re suggesting does (sometimes) work for things like credit card numbers that aren’t sufficiently blurred, because the underlying source material is limited and known. Just because a blurry six doesn’t look like a six any more, doesn’t mean a smart person can’t figure out that blurring an eight would give a different output.

By: citizen

citizen — Wed, 18 Jul 2012 21:30:00 +0000

Oops, I missed…

By: Robert

Robert — Wed, 18 Jul 2012 21:23:00 +0000

Now if only we can cover up all the comments with trollfaces. “Herp derp” plugin just isn’t cutting it anymore.

By: Uthor

Uthor — Wed, 18 Jul 2012 21:05:00 +0000

But if the blur changes the pixels in a specific and predicatble way, can’t you theoretically find a way to undo those changes? Kind of like breaking a code by figuring out the cipher.

By: Duncan Alexander

Duncan Alexander — Wed, 18 Jul 2012 20:57:00 +0000

The way that people undo the twirls is by twirling the opposite direction. No pixel values are changed, they’re just moved.

Blurring on the other hand changes values in the image, so you can’t work backwards. It’s like how you can’t find more detail by zooming in on a digital image.

By: Teller

Teller — Wed, 18 Jul 2012 20:43:00 +0000

Hope it can blur the faces of all those cats and dogs to protect their sense of decorum.

By: Uthor

Uthor — Wed, 18 Jul 2012 20:34:00 +0000

I’ve seen people able to undo the “twirl” process in Photoshop.
http://www.andrewt.net/blog/undo-the-twirl/

I wonder if it’d be possible to do the same with these blurs. If people would upload images with faces blurred out for privacy/safety, but someone figures out the algorithm and can figure out who’s underneath.

By: z7q2

z7q2 — Wed, 18 Jul 2012 20:14:00 +0000

or this

By: citizen

citizen — Wed, 18 Jul 2012 20:12:00 +0000

The Laughing Man face seems a good fit…

By: ldobe

ldobe — Wed, 18 Jul 2012 19:58:00 +0000

Nope. And even so, the meteorite trench of data you leave wherever you go online can also be used to your disadvantage, as all the ad networks have shown.

By: SomeGuyNamedMark

SomeGuyNamedMark — Wed, 18 Jul 2012 19:56:00 +0000

I want it to replace them with smiley faces

By: Timothy Krause

Timothy Krause — Wed, 18 Jul 2012 19:24:00 +0000

Presumably it’s their happy eight-year-old faces, not their impressive passing skills and mid-court game, that would be of interest in that hypothetical video. Another nadir of the security theater state has been reached.

By: jasoneppink

jasoneppink — Wed, 18 Jul 2012 19:21:00 +0000

It’s probably not a good idea to upload sensitive, unblurred video to Google servers. Sure you’re given the option to “delete” the original after you’ve blurred those faces, but can we be certain that a simple subpoena isn’t able to quickly “undelete” that video?

By: JeffreyMartin360Cities

JeffreyMartin360Cities — Wed, 18 Jul 2012 19:18:00 +0000

This is technologically really interesting, and certainly has many applications to protect the identities of people who need protection.

But on another level there is something awful about this. Can I look forward to videos with huge portions of the picture blurred to hide crowds of people? Why is “broadcasting the children’s faces to the world” so taboo?