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Image Scrubber: tool for anonymizing photographs taken at protests

everestpipkin.github.io

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Re: Image Scrubber: tool for anonymizing photographs taken at protests

#391

Post by wool_gather »

Polylactic_acid wrote: post #355
_bxg1 wrote: post #329

Earlier quoted context omitted.

It blows my mind that there are so many ways to screw up something this simple. Edit: to be clear I meant this as a commentary on the technology, not the people making the mistakes

I think there is a need for a dedicated image privacy offline program. On a technical level its very easy to preserve privacy, its just the tools people are using were built for other purposes (Non destructive editing is highly desirable in normal cases). All the program has to do is scrub all exif data, have a censor box/brush that is 100% black and rencode the image so there is no remaining unneeded data.

Good thought; it seems like something the EFF (or maybe the ACLU) would be interested in producing or publishing.

Re: Image Scrubber: tool for anonymizing photographs taken at protests

#392

Post by okamiueru »

radarsat1 wrote: post #141
okamiueru wrote: post #128

Earlier quoted context omitted.

Blur is in effect a lowpass filter on the image. The high frequency information is gone. Reconstruction based on domain knowledge, like AI methods etc is unlikely to be able to reconstruct the distinguishing features between people enough to avoid false positives when used to search for similar people. Then again, maybe groups of people can be associated together, and a poor match is good enough given other clues. So…

> The high frequency information is gone diminished in power. It's only gone if it goes below the quantization threshold. Depends on the filter.

True. I think the reasonable assumption would be a low-pass filter that removes high frequencies altogether. A gaussian filter wouldn't be a particularly good idea.

Re: Image Scrubber: tool for anonymizing photographs taken at protests

#393

Post by jb1533063 »

shavingspiders wrote: post #369
jazzyjackson wrote: post #352

Earlier quoted context omitted.

As soon as deepfakes and "thispersondoesnotexist" started happening I wanted a tool that would replace everyone's face with a auto-generated face just so I could do street photography without feeling like I was invading people's right to obscurity

That's a really interesting idea. I'm not sure what the commercial value would be, but the artistic value (and gain in privacy) would be huge. I'm not sure what you'd do about identifying marks like tattoos, but perhaps that isn't the biggest concern when compared to faces. Could you train a model with your own face as a start, and then run your photos through an existing consumer face-swap app? Or perhaps use a cele…

Commercial value may be for filmmakers who would no longer have to worry about getting waivers from people in the background of live shots. (Not a lawyer.)

Re: Image Scrubber: tool for anonymizing photographs taken at protests

#394

Post by wool_gather »

pbhjpbhj wrote: post #193
chrisseaton wrote: post #127

Earlier quoted context omitted.

> You can't reverse it if the data is gone. That's the problem - the data you think is gone isn't gone. High frequencies are gone.... but you left all the low frequencies, didn't you? You can read a face from the low frequencies.

If you blur then mosaic, or vice-versa, then presumably you get rid of the low and high frequencies? Depending on the detail shown in the original image either, or both, might remove enough information to render the image anonymised. How about replace each face with a "this is not a person" AI generated face, then blur+mosaic. Or just a non-person face using a deepfake system that matches the facial expression?

I would be worried that a generated fake face would be similar enough to the face of a real someone, somewhere, to get that person in trouble. This isn't a crisp portrait photo; a blurry cell phone video with a lot of activity and noise already kind of leaves an opening for mis-identification.

Re: Image Scrubber: tool for anonymizing photographs taken at protests

#395

Post by okamiueru »

thr0waw4y5555 wrote: post #167
okamiueru wrote: post #128

Earlier quoted context omitted.

Blur is in effect a lowpass filter on the image. The high frequency information is gone. Reconstruction based on domain knowledge, like AI methods etc is unlikely to be able to reconstruct the distinguishing features between people enough to avoid false positives when used to search for similar people. Then again, maybe groups of people can be associated together, and a poor match is good enough given other clues. So…

Blur deconvolution is not exactly a new method. Easy to find examples of reconstruction from blurred images. Eg, https://www.instantfundas.com/2012/10/how-to-unblur-out-of-f...

I don't when de-blurring would be a novel idea. I think newer methods that use machine learning can produce very good results. But the math of it is much older than any computer implementation.

If you remove high frequency details, you in effect remove distinguishing features. That it is possible to create an absolutely convincing high-detail image that if blurred, gives the same "original" blurred image doesn't mean you have the correct deblurred image.

With not too fancy methods, I'm pretty sure you can make a blurred image identify as any multiple people.

I don't think this is a controversial statement either. In any case, this is a tangential discussion, since blurring to hide identities is a flawed method to begin with. With video recording, tracking, grouped individuals, etc, I'm sure reconstruction with good databases of likely subjects can have some surprising accuracy. So, better to avoid it altogether.

That said, one image, sufficiently blurred with a proper low-pass filter (i.e not a softer gaussian type, but one that just removes frequency ranges altogether), will absolutely not contain information to identify someone. The information literally isn't there. A large number of people are an equally good match, and then no one is. But, since combined with other methods I mentioned, it's a bad idea, then, yes, it's a bad idea.

Re: Image Scrubber: tool for anonymizing photographs taken at protests

#396

Post by herewulf »

samstave wrote: post #198
Ansil849 wrote: post #119

Some tips to maximise user privacy while deploying this tool: 1) The code, for now, runs locally. This is good. To avoid the possibility of the code being tampered with at a later day (for example, it could be modified to send copies of the image to a server), download the webpage and use the saved copy, not the live copy. 2) Do not use the blur functionality. For maximum privacy, this should be removed from the app…

So based n all the replies, can someone design the most resilient facemask that can never be understood by facial AIs?

Once a face is captured that image data can be retained forever while the image recognition continually improves and then repeatedly reprocessed for matches. Best not to show your face at all if you don't want to be held accountable.

Re: Image Scrubber: tool for anonymizing photographs taken at protests

#397

Post by okamiueru »

pizza wrote: post #255
okamiueru wrote: post #128

Earlier quoted context omitted.

Blur is in effect a lowpass filter on the image. The high frequency information is gone. Reconstruction based on domain knowledge, like AI methods etc is unlikely to be able to reconstruct the distinguishing features between people enough to avoid false positives when used to search for similar people. Then again, maybe groups of people can be associated together, and a poor match is good enough given other clues. So…

I mean, if you have a prior probabilistic model for what a face looks like, you could combine that with standard deconvolution and get a scary good reconstruction I imagine

You can get a scaryly real like looking high detailed image that blurs to something really close to the original blurred image. Yet, it won't look like the original image, and won't identify the person.

Re: Image Scrubber: tool for anonymizing photographs taken at protests

#398

Post by thr0w__4w4y »

jb1533063 wrote: post #393
shavingspiders wrote: post #369

Earlier quoted context omitted.

That's a really interesting idea. I'm not sure what the commercial value would be, but the artistic value (and gain in privacy) would be huge. I'm not sure what you'd do about identifying marks like tattoos, but perhaps that isn't the biggest concern when compared to faces. Could you train a model with your own face as a start, and then run your photos through an existing consumer face-swap app? Or perhaps use a cele…

Commercial value may be for filmmakers who would no longer have to worry about getting waivers from people in the background of live shots. (Not a lawyer.)

Also not a lawyer, and US-based in case it varies by country.

Do you know if a waiver is needed in this case? My understanding is that I can walk down a sidewalk, around Disneyland, around a resort, and film anyone / anything in plain sight. (I don't do that, by the way...) In other words, assuming you're not climbing over railings etc., if you can see it with your eyes, you can film it or photograph it.

Wonder if anyone here (plenty of legal eagles I'm sure) can confirm this or correct this. We don't need to get bogged down in corner cases & rare exceptions... for example, I think I heard that in some states, if the police ask (demand?) that you stop recording, you have to, otherwise you're in violation of the law... but even as I type that, as an American, it just sounds wrong... but I don't know.

Re: Image Scrubber: tool for anonymizing photographs taken at protests

#399

Post by ikeyany »

jazzyjackson wrote: post #352
_bxg1 wrote: post #233

Earlier quoted context omitted.

A replacement for blur could just be black boxes. Seems easy and safe enough.

As soon as deepfakes and "thispersondoesnotexist" started happening I wanted a tool that would replace everyone's face with a auto-generated face just so I could do street photography without feeling like I was invading people's right to obscurity

A tool that automatically turns background faces into the faces of random animals would actually do quite well.

Re: Image Scrubber: tool for anonymizing photographs taken at protests

#400

Post by mikepurvis »

thr0w__4w4y wrote: post #398
jb1533063 wrote: post #393

Earlier quoted context omitted.

Commercial value may be for filmmakers who would no longer have to worry about getting waivers from people in the background of live shots. (Not a lawyer.)

Also not a lawyer, and US-based in case it varies by country. Do you know if a waiver is needed in this case? My understanding is that I can walk down a sidewalk, around Disneyland, around a resort, and film anyone / anything in plain sight. (I don't do that, by the way...) In other words, assuming you're not climbing over railings etc., if you can see it with your eyes, you can film it or photograph it. Wonder if an…

Also not a lawyer, but I think it mostly has to do with commercial use. Filming people at Disney for your Instagram followers is different from making a feature film and turning everyone standing around on a busy street into uncredited extras.

This particular site is with respect to Canada, but I'm pretty sure the same basic idea applies everywhere:

"When publishing photos for commercial purposes: You need the permission of every identifiable model in the photo, even if the photo was taken in a public space. For example, if a photo has 10 identifiable models in the photo, you would require a model release for each of them."

https://www.lawdepot.ca/law-library/faq/model-and-entertainm...

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