Use makeup to hide your face from detection systems using the Viola-Jones method | Hacker News Reader

Use makeup to hide your face from detection systems using the Viola-Jones method

ahprojects.com

51 pointsthenbrent13 comments

Read his previous posts to learn more about the project and the detection method he's testing against.

I ran this same image through our face detector, with results I could easily predict: http://demo.pittpatt.com/detection_demo/view.php?id=JSCV5AH9... We don't find any of them (blue and yellow are low confidence faces). We do "well" by our definition, terrible by the writer's.

So, problem #1: using hand-drawn faces (these are fairly stylized) is a really bad way to test a face detector. No one "in the real world" wants to detect or recognize hand-drawn faces, and so no one trains with hand-drawn faces. We, specifically, err on the side of choosing to exclude stylized faces from the faces category (though most frequently these would be "don't-cares").

Problem #2: Using a single image is actually a bit misleading, because if you really want to "test" methods for thwarting detection, you need to use a video. Those slight variations in pose and lighting are going to make it much easier to pick up the face and filter out the misses.

Lastly, if you wanted to "defeat" a dystopian mass surveillance system, you don't want to prevent detection, but recognition. It's far easier. And to prevent good recognition over a huge dataset (ie, the population of the world), you just need to "remove" information from your face. Wear big ol' sunglasses and a hat. Far more effective, far less conspicuous.

(edit to add: if you click 'thesis' at the top, and read the top few entries, he shows alot more about how viola-jones and the haar wavelets are used to find face regions. It's an interesting visualization. It also does a great job explaining why the makeup trick works)

The headline on this HN submission is a bit ambiguous: are the face-detection systems using the Viola-Jones method, or the the face-hiding technique a Viola-Jones method?

Turns out, it's the former - http://en.wikipedia.org/wiki/Viola-Jones_object_detection_fr...

Technically, both. You use knowledge of the cascades to design the antipatterns.

My Cannon camera picks up the 2nd face top row.

Well sure, machines might not detect your face, but everybody around you is going to be able to describe the weirdo who had on camouflage makeup.

Honestly, I doubt it. They'll remember the makeup probably, and likely little else. Unless your hair is also noteworthy, I doubt most would remember it.

I remember the story of the naked bank robber, who got away with it because nobody could describe his face, as they were too distracted by his nudity.

Also known as the Lady Gaga method.

Ehh, it's a bit of a meh.

Anyone who is using face detection for a serious purpose will make you take off that abnormal makeup first

I disagree, anybody who is doing face recognition for a serious purpouse is probably using lots of surveillance cameras. In the setting where you can make someone take off makeup it's probably easier to just ask them for their credentials.

Agreed, however I haven't seen anyone mention the more obvious (or maybe not so obvious) point. That sort of disguise might evade the algorithms, but it would be glaringly obvious to any person. It's rare to have surveillance 100% managed by cameras and computers alone, there is usually some amount of physical guard presence. Even a semi-catatonic guard would likely investigate a person made up like that moving through a crowd. Especially if they were male.

Fantastic! I just always knew that in our distopian cyberpunk future, we mercenary code gargoyles would all be covered in some kind of digital war-paint-camouflage as we wage secret mercenary wars on behalf of covert multinational-mega-city-corps.

You laugh, but we as humans have no problem identifying the faces with odd makeup as faces.

Not in low light conditions, or when surrounded by a distracting background.

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