Adversarial IR Hoodie Lets You Own The Night In Anonymity

If you’re in the market for something to obfuscate your nefarious nocturnal activities, rejoice — this adversarial infrared hoodie may be just what you’re looking for.

Not that we condone illegal activities, of course, and neither does artist [Mac Pierce], who created “The Camera-Shy Hoodie.” His purpose seems to be exploring the nature of the surveillance state, or rather to perplex it in the name of anonymity. The idea is simple — equip a standard hoodie with a ring of super-bright IR LEDs, and control them with an RP2040.

We’ve seen blinding hoodies before, but here the LEDs strobe on and off in one of three different patterns, all of which are timed to confound the autoexposure mechanism in just about any surveillance camera by not giving it time to adjust to the rapidly and drastically changing light level. The result is near-total obfuscation of the wearer’s facial features, at least when the camera is in night-vision mode. Check out the results in the video below.

There are some nice touches to [Mac]’s approach, like aluminum PCBs for the LEDs and the use of soldered-on fabric snaps to attach them to the inside of the hoodie, making them easy to remove for laundering. With the LEDs peeking through holes in the fabric, the hoodie looks pretty run-of-the-mill — until, of course, night falls and the USB battery bank in the hoodie’s pocket powers up the light show.

Granted, this won’t exactly help you avoid detection — the big ball of light around your head will be instantly seen by even the most casual observer. But at least it makes it easier to keep your face to yourself. And it won’t help much in daylight — for that, you might want something a little more like this passive adversarial ugly sweater.

75 thoughts on “Adversarial IR Hoodie Lets You Own The Night In Anonymity

    1. It’s using 850 nm IR LEDs, those can be seen as a faint dark red glow, and wearing sunglasses may help you better notice the glow.
      (I once looked at a security camera that had a ring of IR LEDs, while wearing sunglasses, and I was surprised how easy it was to see the glow)

  1. The interesting question is whether something like this could be organised to look like the blobby/pixellated effect usually used to conceal the identity of “innocent bystanders” in photos.

  2. I wonder if this could be achieved by just standard reflective tape as used on a lot of sportswear already?

    All you’ve got to do is have enough brightness coming back to blind the sensor / force the AE algorithm off the deep end.

    1. Does standard reflective tape used in sportswear reflect light in the relevant infrared frequencies? They’re obviously optimised for the broadly white light emitted by car headlights, how far out of the visible spectrum do they work?

  3. I love the idea for privacy. But I suspect that if you grabbed a single frame and manually adjusted the brightness and darkness levels to stretch over the full range you could still pull out a face. Even if this required removing the very brightest levels altogether and replacing them with black.

    1. Thinking about it more the image quality would probably not work well for traditional trained neural networks, but human brains could probably still identify the face, even if the useful range was 4+ shades of grey.

    2. Very likely the image will be completely blown out – that seems to be the intent of the concept.

      It’s also much easier usually to recover details from under exposure than over exposure.

  4. Would this work around one’s license plate, now all the speed cameras here use infrared flash?
    I’m asking for a friend ;-)
    (No seriously, haven’t had a ticket in at least five years)

    1. “Back in the Day ™” We had some gain adjustment electronics between the camera and the capture card that would reduce the levels by an order of magnitude, so that a front license plate can still be captured clearly at night time with the headlights on. That was around 1999-2000.

      Since then the analog camera electronics and the digital capture electronics have merged into one device. But also the technology has improved a lot. You can’t relally block the plate with additional light. If the captured picture has enough dynamic range you can do whatever you want and it is still possible to read the plate. Speeding cameras are build specifically for this purpose.

    2. I think a setup with thin louvers would be better. Like the Air vents inside your car. They would be almost invisible at ground level, but cover the plate at the high angle those cameras are mounted at. The only problem is it they can’t be hidden, so if a cop ever inspected your stopped vehicle they would know what you did.

      1. Where I live, speed enforcement by camera is done almost exclusively by rigs mounted to vehicles, so if you can see the plate from the road you’re not going to have any luck.

        Not that they’re particularly useful now that the conservative local government has mandated all of them have “safety flags” and a neon green wrap.

  5. I wonder if these high power IR LEDs are safe for the eyes. IR light is not visible (or barely a reddish glow), but these LEDs emit a lot of power, and here there are close of the eyes. And by night, pupils are wide open.

      1. IR “heat” is in the 2-10 micron wavelength range, which gets stopped by the first few skin cells.
        These IR LEDs are in the 0.7-0.9 micron range: this easily passes into the eye and is focused by the eye lens.
        It’s a valid concern. Don’t put a high power IR LED up against your eyeball.

      1. I have been told by old timers (long before I was one) it was fairly common for blacksmiths to go blind back in the time of horses, so it seems possible fires could cause issues, the sun does, so likely matter of intensity and time…

        1. My dad is in his late 60s and has been a mechanic by training and trade since his teens. Convincing him to wear appropriate protective equipment has always been a challenge, he’s very VERY lucky to still have two working eyes, his hearing is absolutely terrible, he’s smashed his fingers and thumbs many times.
          Long story short, I suspect blacksmiths had enough risks to their sight without even needing to bring in infrared risks.

      2. Yeah. I have a couple very high-power LED spotlights for hunting. It is not recommended to look into them when powered on, regardless of what wavelengths you can perceive. It doesn’t need to actually register with your rods and cones to damage them.

      3. Have your eyes ever been hurt by an IR laser? They’re extremely dangerous; you don’t know there’s a danger until you’re blind. So it’s an entirely valid concern.

        However, these are probably too defocused – as they want wide angle – to have any risk of causing damage.

    1. The LEDs may be close to the eye, but aimed away.
      Just don’t stare up close at the faint red spot when you look at them.
      The risk is still pretty low though. You’re not going to get enough power density to the retina to cook it unless you try really hard.

      1. It seems like getting really up close to inspect a very dimly lit light on someone’s clothing would be *exactly what someone might do. Like, look right at it if they were sitting on the bus next to me.

    2. IR LEDs aren’t nearly as intense or concentrated as even a low power IR laser. It’s very unlikely there is any risk of long term damage.

      Maybe, if you held it up to your eye point blank and stared into for a while, you could do some damage.

  6. > ball of light around your head will be instantly seen by even the most casual observer
    Only if a human is actively watching the screens, depending on the number and placement of cameras the vast majority of video footage is only ever consulted retrospectively.

    Although if only one person is walking around with a ball of Infra Red Light around their head, it does make tracking them backwards and forwards in time using multiple video recordings easier.

    1. i was thinking about this…it really showcases the difference between anonymity and pseudonymity.

      i think one advantage of this is it can be turned on and off at will. so you can do parts of your mission as a glowing ball and then turn it off and blend into a crowd…don’t even need to jump into a phone booth to accomplish that wardrobe change!

  7. There are plenty of variants on this concept going back a good decade or two. They rely on a given security camera having the right combination of adaptive exposure control and adaptive exposure control response time of just the right speed. Per-frame or very fast exposure control will adapt to the bright emitters helpfully clearly illuminating your face fast enough to capture your face during the illumination interval. Slow adaptive exposure response times will not respond by the time the active interval ends, and be correctly exposed to capture your unilluminated face. High dynamic range sensors (as are becoming more common in higher end security cameras) are just flat out immune to this sort of attack without pumping tens to hundreds of watts through the LED array.

    It’s a great idea in theory, but pulling the hoodie further down your face is more universally effective at all sensor wavelength and against all camera framerates and exposure controls (and against any mk.1 Eyeball observers).

    1. Camera processors are getting better and better. After a while, it may be possible to have cameras with sensitive enough sensors and fast enough processors that can adjust settings per frame and use real-time HDR-like processing, so this hoodie will be like walking around with a lamp over your head.

      It will make their job easier!

      1. “After a while, it may be possible”

        They’ve been available on the commercial market for years in top of the range surveillance cameras. Very expensive, based on specialised variants of the nice large ‘full frame; sensors used on DSLRs and later MILCs. The stock bayer-filtered versions already have 14-15 stops of dynamic range, by stripping that filter and driving some pixels at different rates (trading resolution for dynamic range) you have pretty insane capability, imaging bright lit sky and deep shadows within the same frame. Here’s an exmaple form a decade ago:
        And that’s just a single sensor body, you’ll often see these deployed as multiple sensors with overlapping coverage and sometimes different capabilities (e.g. RGB and nIR comounted, sometimes with more esoteric filtering for more specialised applications like chemical release monitoring).

  8. “Yes sir. Re-targeting the micro drones on ball of light subjects.” It doesn’t have to be police. If you have opponents they can do this easily, as we see in Ukraine.

  9. It seems to me that if I put VERY powerful IR leds all around my camera that was 10x or more the brightness of the hoodie that I would illuminate the face in that hoodie. Similar to someone blinding me with a penlight at night then I beam them back with a floodlight

  10. So now all we need is a passive IR sensor to activate a visable floodlight at night. All we need now is to have porch pirates wearing cheap IR lights on their hats.

    Or maybe Mark Rober will make IR homing drones to drop glitter all over them.

    1. Afaik most cheap “night vision” security cams are just cheapie phone camera modules with the IR filter removed from the optics. They cannot be switched to a mode which blocks the incoming IR deathbeam. It’ll still wash out in “daylight mode.”

  11. Upside: if you are a criminal caught on candid camera, then it’s harder to catch you. Downside: if you are a *suspected* criminal, the hoodie circumstantially links you to the crime.

  12. I wonder why I still haven’t heard of people installing an array of high power IR leds around their license plates. This should make the plates unreadable to speed cameras, but wouldn’t be very noticeable for a casual observer.

    Disclaimer: don’t do this.

  13. I like that this is an art project. Because an actual criminal wouldn’t give two craps- even with home security systems and all they can come with a brick, get in and clean the place out in minutes, well before any law enforcement or security shows up.
    Or just wear a covid mask, or a regular mask, or any number of other stuff.
    All of this assumes police are interested in solving crimes like robbery. They aren’t. They barely even will fill out paperwork or file a report for your insurance, even when asked repeatedly. There is zero chance they will look at security footage for anything short of murder, and even then I’ve seen enough First 48 to know that after, oh, 48hrs, they give up on that too.

  14. I placed a motion-sensor controlled high-power IR lights on my house, directed at my neighbor’s security cameras. The lumens are dialed to 11, duty cycle very low and cycle frequency only about five times per second. Works in daylight. They say the image gets all washed out and blinky.

  15. Your can literally slow down the feed to .5 in the video and make out the person’s face as clearly as you could normally with that quality of camera, and the mannequin is extremely visible and detailed. All this does is alert an active security person to watch what you’re doing. Facial recognition is done with computers and this wouldn’t do anything to stop it.

  16. How about we put this same tech on the brim of a hat.
    Still get the same blinding/obscuring effect on security cameras, without worrying about eye damage from the IR light on the wearer.

  17. Hmm – interesting, but actually most of our recognition is achieved by the way a person walks, their “Gait”. This is very hard to change as it’s biomechanical and not easily circumvented by wearing a hoodie or a mask.

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