Ask HN: What are the implications of increased mask use on surveilence systems? - onewhonknocks
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Pick-A-Hill2019
I'm guessing you mean something like 'how are surveillance systems adapting to
the wide use of face masks in public'. *

There are a few techniques including

1) Gait analysis [1]

2) Ear shape analysis [2]

3) Running image recognition on something the person is wearing rather than on
their masked face. I can't find it right now but I recall reading a Google
research paper a few years back that managed a high (+87% certainty) just
based on a person’s shoes. [Edit, after a bit of ‘Ducking’ came across [3]
which is a 2016 patent awarded to Disney which is close enough]

Think about how often you see someone wearing the exact same shoe as you are.
Same goes for things like backpacks, caps with logo on etc.

At some point 'Bob' or 'Alice' is likely to be carrying a cell-phone (sadly an
almost certainty these days) or have to use public transport or leave their
house or walk in to a shop and buy a drink on the way. There is a push in a
lot of parts of the world to pay by card only and some shops are starting to
refuse to accept cash and the same goes for public transport.

With sufficient coverage once you have managed to ‘lock on’ to a unique
characteristic (shoe, gait, distinctive item of clothing) even if you don’t
manage to get lucky that time you just let the image recognition trawl through
all the archived footage and at some point chances are good that you can
identify them well enough to know which door to knock on. Given that people
are creatures of habit (daily commute, same route, same time of day) even if
unable to track back to a physical location you just wait where they tend to
be at certain times. The hunter only has to get lucky once, the rabbit has to
be lucky each time they pop their heads out.

[1] [https://www.scientificamerican.com/article/motion-capture-
su...](https://www.scientificamerican.com/article/motion-capture-
surveillance/) &
[https://apnews.com/bf75dd1c26c947b7826d270a16e2658a](https://apnews.com/bf75dd1c26c947b7826d270a16e2658a)

[2]
[https://www.sciencedirect.com/science/article/abs/pii/S09574...](https://www.sciencedirect.com/science/article/abs/pii/S0957417416304341)

[3] [https://thenextweb.com/insider/2016/07/29/foot-
fetish/](https://thenextweb.com/insider/2016/07/29/foot-fetish/)

* Where possible I have used links that are a few years old. Feel free to Google some of the terms used in the research papers for more up to date information.

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onewhonknocks
Yes, that is exactly what I meant. Thank you for this very thorough response!

~~~
Pick-A-Hill2019
You're very welcome and thank you for taking the time to say 'Thanks'.

I saw this post bubbling up and down the HN submission rank for a while (12+
hours) before posting my comment.

Here on HN there are undoubtedly many people more familiar with (and more up
to date with) this particular topic than I am (and I was rather hoping that
they would chip in with something but understand why they haven’t).

At this moment of history - Topics and discussions on what the state-of-the-
art computing horsepower can and cannot achieve is (being blunt) not something
that could ever freely be discussed in a public forum.

Which ever side you happen to be on. Welcome to the Future.

