Facial Recognition

In New Tests, Facial Recognition Products Are Consistently Thwarted by Masks

Defeating surveillance is a powerful argument for covering your face.


Ongoing tests of facial recognition technology continue to show that the technology is baffled when people wear masks of the sort that have become widespread (and even mandatory) in some places during the current pandemic. Forty-one newly tested algorithms—some of which were designed to compensate for face coverings—show the same dramatically elevated error rates as those examined earlier.

The tests have important implications for privacy at a time when surveillance technology is growing increasingly pervasive—but so is mask wearing. These studies are of interest, too, in an era of political instability and growing concern over law enforcement excesses, when people may have a strong interest in making identification of opponents and protesters difficult for the powers-that-be.

The tested facial algorithms are additions to those scrutinized by the U.S. government's National Institute of Standards and Technology (NIST) in a report issued in July. "Now that so many of us are covering our faces to help reduce the spread of COVID-19, how well do face recognition algorithms identify people wearing masks? The answer, according to a preliminary study by the National Institute of Standards and Technology (NIST), is with great difficulty," NIST summarized its findings at the time. "Even the best of the 89 commercial facial recognition algorithms tested had error rates between 5% and 50% in matching digitally applied face masks with photos of the same person without a mask."

While an error rate of 5 percent at the low end may not sound like much, that's under near-ideal conditions. The algorithms were tested in one-to-one settings, of known subjects, like you might find at a passport checkpoint. And most of the systems suffered much higher error rates when dealing with covered faces.

Because of the growing popularity of face masks even before the pandemic, and their booming and often mandated usage since COVID-19 spread worldwide, facial recognition companies have raced to develop algorithms that can identify people despite coverings. NIST plans to test such technology in the future to see if it delivers as promised. But this latest round of algorithms isn't part of that study.

"These algorithms were submitted to NIST after the pandemic began," Chad Boutin, a science writer for NIST, told me by email. "However we do not have information on whether or not they were designed with face coverings in mind. The research team plans to analyze the data and issue its next [Face Regnition Vendor Test] report in the next few months, and will continue to report results on new submissions on the face mask webpage."

But some of the 41 newly examined algorithms are very clearly intended to compensate for face mask usage.

Dahua, a Chinese company, boasts that its facial recognition technology allows for "attributes including gender, age, expression (happy, calm, surprised, sad, and angry), glasses, face masks, and beard & moustache, which makes searching and tracking subjects of interest more efficient." In the NIST test, the error rate of Dahua's algorithm went from 0.3 percent with an uncovered face to 7 percent with a face mask.

Likewise, Rank One insists that "accurate identification can be achieved using solely the eye and eyebrow regions of the face." The company's error rate went from 7 percent without masks to 35 percent with them in the NIST study.

Vigilant Solutions, which is well known for its vast license plate reader network but makes no claims about compensating for covered faces, went from a 2 percent error rate without masks to 50 percent with them.

Some of the products had error rates approaching 100 percent with covered faces, although these were generally less-accurate algorithms to begin with.

Again, these are facial recognition algorithms tested in one-to-one settings of the sort used to confirm an identity to unlock a phone or at an access control point. "Future study rounds will test one-to-many searches and add other variations designed to broaden the results further," according to NIST.

Even before that future study, however, we know that one-to-many comparison of strangers on the street or in a crowd to databases of images is much more challenging. It can be thrown off by many factors—including age, sex, and race—even when people's faces are uncovered.

Such "systems tend to have lower accuracies compared to verification systems, because it is harder for fixed cameras to take consistent, high-quality images of individuals moving freely through public spaces," noted William Crumpler of the Center for Strategic and International Studies earlier this year.

Getting high-quality images is especially difficult when people are actively trying to avoid identification. And while such avoidance is difficult to pull off at a passport checkpoint or when trying to unlock a device, resisting identification is par for the course at a protest or on a sidewalk. Last year, police in the U.K. stopped pedestrians who covered their faces when they approached facial recognition cameras precisely because that was seen as an effort to thwart identification.

Now, governments are simultaneously ordering the public to mask-up in public places under threat of stiff fines and fretting over the resulting impact on surveillance. "We assess the widespread use of masks for public safety could likely continue to impact the effectiveness of face recognition systems even after federal or state mandates for their use are withdrawn," a Department of Homeland Security notice warned in May.

Given that the algorithms designed to compensate for face masks necessarily rely on the remaining exposed portions of the face—specifically, the eyes and eyebrows—donning hats and sunglasses may be all that's necessary to curtail the effectiveness of facial recognition technology.

The technology has raised enough privacy concerns that there has been enormous push back against its deployment. Boston and San Francisco are the largest of the U.S. cities that have banned the use of facial recognition technology by law enforcement agencies. Early in August, in a decision that could have wide ramifications for the U.K.'s growing surveillance state, a British court ruled against the use of the technology by the police.

The news that facial recognition technology can be defeated by cheap and ubiquitous face masks may well come as good news to Americans in the streets protesting biased and abusive law enforcement, or just in favor of reforming the way police do their jobs. Such news may also be welcomed in a country bitterly divided into hostile political factions. Half of the country is bound to distrust surveillance technology in the hands of whoever wins the November election.

That means large numbers of Americans should be pleased to know that they have a good chance of preserving their privacy with cheap pieces of fabric stretched across their faces.

NEXT: A Summer Without Summer Movies

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    1. Finally a story we can all unite behind…Mask up to stick it to the police state!

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  2. Yet another benefit of masking-up.

    1. Yes. And then there are shockingly moronic takes like this from a life-long libertarian and supposed leader in the movement.

      1. “Adding to my post-lockdown predictions: the face mask will be rightly regarded as a symbol of obsequious obedience and grotesque compliance with arbitrary and ignorant authority.”

        He’s absolutely correct.
        It’s social conditioning rooted in shallow ignorance and your desire to virtue signal your altruism.
        You think you’re being considerate, but what you’re really doing is reinforcing irrational fear and a culture where one’s neighbors are a threat.
        You’re a fucking tool

        1. He was joining tony yesterday in condemning all those who didn’t cower in fear and blame trump for covid as a cultist.

          1. Shitlord told Tony “Just kill yourself. You have no value.” To which I responded:

            I think Shitlord here is the most honest of the Trump cultists. He just lays it out bare, what he believes: kill all the non-believers.

            You are a habitual liar that makes shit up and misquotes people to suit your demented ideas of what you think they said.

            1. You are lying here, eunuch.

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  3. I wonder what happens when the pandemic fades if the state criminal laws against wearing masks will be invalidated by this experience?

    1. Well, I figure I can claim a religious exemption from those laws, being a WASP and all.

    2. Just claim you’re being a good citizen “having learned the lesson of Covid-19” and that you plan to wear a mask henceforth when in public to protect the health of your fellow man. When they say that’s not ok, you play the same card the leftists are playing, but rather than screaming “racism” you scream “you don’t care about people’s health!”. It may not work but it will show the hypocrisy of the statists.

      1. Just tell them you think you’re coming down with the flu and don’t want to get other people sick.

  4. kewl but still not acceptable trade-off. tired of making Jesse James jokes every time I bandana-up

    1. Nothing beats putting on my hat, pulling a bandanna on my face, and then going into the bank. 😀

      1. “alright I’m gonna knock over this 7-11 keep it running.”

  5. So at this time a law, passed by the elected legislature, forbids wearing a mask “to alter or conceal identity”.
    At this time an executive order based on “science” that ONLY applies to the Communist Chinese Virus and NO OTHER illness, requires wearing a “cloth face covering”, which of necessity both alters and conceals identity.
    I feel like the poor folks confronted by two police officers; one yelling “police, show me your hands!!”, and the other yelling “police, don’t move!”.
    Whatever I do, I am in violation of something.
    I think I read a novel about this once upon a time – – – – – – – – – –

    1. “Communist Chinese Virus“

      Can a virus be communist? I’d think of a virus had a political philosophy it would surely be libertarian. Easier to spread from host to host that way.

      1. When a Communist Chinese government sends over a million people to international destinations from a city that they have locked down from internal travel, then yes.

        1. Intentional or did they just not give a shit?

          1. A little of both?
            Consider that they banned travel within their own borders while allowing people to travel internationally with no unique restrictions

            1. … while telling WHO that there was no evidence of human to human transmission.

    2. Ahhhh, but that’s a very thin line that can be sliced. The mask being worn to (notionally) protect against Covid transmission is “altering or concealing identity”, but it’s not being worn to “alter or conceal identity”.

      That is, while it accomplishes the task, it is not the primary goal.

      1. Which means there’s a wonderful future defense against people being prosecuted under that law.

        “I was wearing this mask to protect against disease.”

        1. “It’s a Richard Nixon mask like the one from Point Break.”

          “I’m protecting myself primarily from sexually transmitted diseases.”

          1. I’ve always contended that Pat Nixon would never have cheated on her husband, so the Nixon children are evidence of Immaculate Conception.

    3. Was not novel comrade, was brilliant idea I had! You show me man and I show you crime! – L. Pavlovich Beria

  6. No it is not an argument for covering your face. If facial recognition is a violation of privacy rights, then the solution is to ban it. The solution is not to accept it and walk around with an idiotic mask on to thwart it.

    1. Yup, you’re right.

      Now use that argument with the TSA the next time you want to fly.

      1. That doesn’t even make any sense. Beyond that, wearing a mask is a bigger imposition on my freedom than facial recognition ever will be.

        1. yes yes yes

        2. This. Facial recognition does not impair my breathing.

    2. They are both solutions. Repealing/passing laws is a long term solution (normally). Wearing a mask is an immediate short term solution and has the benefit of decreasing the effectiveness of facial recognition software perhaps delaying its spread through out society.

      1. No, it spurs the development of better algorithms for more accuracy.

        1. Which spurs people to deploy new low tech ways to get around the new and improved algorithms. Probably leaked by the same guys who created the new and improved algorithms, in order to get some more of those lucrative cost + profit contracts. Soon everyone will be walking around in black face to avoid the police state surveillance and the anti-police, anti-racist heads will explode – mission accomplished.

      2. Is wearing a mask an immediate short term solution? I have a feeling it will be a long term solution. Since most people are okay with wearing a mask there is no reason for it to end. The virus to some extant may be with us for a long time and even if it dies down flu season will keep the masks on.

        Wearing a mask is a simple thing to do to save a life. So is driving 25 mph on the freeway. So is limiting sugar sold in stores.

    3. You’ll have private roads before you have privacy rights.

      Meantime, give’em the middle finger and mask up.

  7. Aren’t there laws against wearing masks in some places?

    I bet, somewhere, right now, it is both illegal and required that you wear a mask.

    1. Something similar actually happened, sort of, for a time, when automobile seat belts were first required to be worn. There were lots of the old “lap-belts” still in use, and although safety experts were telling us that to do so was not recommended, that the injuries they caused more than outweighed the benefits, and that only the “three-point” systems should be used, it was still a violation NOT to wear them. Ain’t government wunnerful?

      1. Or, driving around in a ‘46 Ford that didn’t not come from the factory with seat belts, and a cop pulling you over and giving you a ticket for not wearing your seat belt.

    2. Executive orders trump actual laws. Duh.

  8. Looks like facial recognition isn’t, at least in the near term, all that useful to the state.
    Totalitarian symbolism that completely disrupts common human interaction (such simple but vital gestures as smiling at someone) on the other hand…

  9. Perhaps a personalized machine readable bar code could be printed on the mask. The same technology that is used to read license plates should be up to the task.

    1. But people might change their masks. We’d better make people get that barcode (or maybe just a serial number) tattooed on their body somewhere. Maybe the inside of the forearm?

      1. Forehead.

        1. Forehead

          Are hats still a thing?

  10. Perhaps, and this is going to sound crazy, maybe laws requiring masks and laws prohibiting them are equally stupid, equally anti-liberty, and equally wrong.

  11. Best news I’ve heard all year. A fake pandemic is thwarting surveillance and invasion of our privacy.

  12. Always look on the bright side.

    My neocon co-workers always complain about the quality of public schools, but then complain when the state tells them that they do not have to send their kids to public school.

    They complain about the cameras on the sidewalk, but then complain when the state recommends wearing a mask that hides their identity.

    I revel in the anonymity of wearing a mask.

  13. Fact is, it is the ONLY valid reason for slapping a mug nappie accross your smile. Funny thing I’ve observed lately.. prior to “cornoa times” bank, smost public places, etc, prohibited entry to those wearing face coverings. (we want our suvrveillance equipment to get a GOOD look at you, and probably even to identify you from our database. Now, the virus trums all….EVERYTHING else goes by the board “because corona”. Used to be, if one carried a weapon in pubilic while masked one could assure one’s self they WOULD likely be at least detained for questioning.

    Now if one does NOT have the mug nappie suitably fitted, one can cound on being accosted on that account. Oh well.. the surveillace state now must take a back seat to the pseudo-medical state. Hah, the joke’s on them, ain’t it?

  14. Good points, but police have not, in the past, shown all that much concern for whether or not they have the right person when they accuse someone of a crime. They just want to find someone. If so, why would they care about the accuracy of their facial recognition algorithm? If prosecutors, jurors, expert witnesses, and people in general all agree that facial recognition technology is a valuable tool in law enforcement, police will use the tool, as long as it makes a match. Remember lie detector tests? Virtually no one thinks they are accurate, but we still use them. They became established back when we thought them accurate. Why would facial recognition be different?

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  16. Hong-Kong er knew what was up? With the CCP surveillance state creeping into HK, everyone started masking up last year amid the protest. As an added bonus, everyone was prepared for COVID having learned their lesson from the SARS epidemic.

  17. Hong-Kong ers knew what was up? With the CCP surveillance state creeping into HK, everyone started masking up last year amid the protest. As an added bonus, everyone was prepared for COVID having learned their lesson from the SARS epidemic.

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