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--- | ||
layout: post | ||
title: "Biometry application" | ||
description: "What we do is not evil." | ||
category: "news" | ||
tags: [] | ||
--- | ||
{% include JB/setup %} | ||
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<p> | ||
April 1st, 2012 | ||
<p> | ||
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<p> | ||
Dear CGAL developers, Dear CGAL users, | ||
</p> | ||
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<p> | ||
In order to put an end to rumors about GeometryFactory | ||
selling CGAL to Facebook for a biometry application, | ||
let me give you the background, and let me explain why | ||
we think that what we do is not evil. | ||
</p> | ||
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<p> | ||
Just as nuclear energy can be good or bad, biometry is | ||
neutral as such. The particular application we contribute | ||
to is about matching lip prints on cigarette butts with | ||
Facebook users who threw the butts away. This allows people | ||
to act, who are fed up with cigarette butts lying around | ||
virtually everywhere: in front of the Statue of Liberty, | ||
as well as along trails in Yellowstone National Park. | ||
</p> | ||
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<p> | ||
One of the goals of social networks is social engineering, | ||
that is making mankind better. The workflow of the | ||
biometry application is | ||
<br> 1 that you take a picture of a cigarette butt lying at a | ||
place where it should not, | ||
<br> 2 that you upload this picture to FB together with the GPS | ||
coordinate of where you shot the picture, so that FB can | ||
identify the culprit by matching the lip print on the | ||
cigarette butt with the extensive database of faces. | ||
<br>3 that FB tells him or her that this is not a well educated | ||
behavior (smokers in fact know that it is not nice), and | ||
puts repeat offenders on a wall of shame. | ||
</p> | ||
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<p> | ||
As it is technically rather fascinating, let me just | ||
tell you why it is not a trivial problem. We can't reveal | ||
all the details as we filed a patent. Lips leave prints, | ||
just like fingers do, but fingers tips are flat compared | ||
to lips, cigarettes are cylindrical, the max curvatures | ||
of lips and cigarettes are mostly orthogonal where | ||
they touch. Just as maps are distorted towards the poles, | ||
so are the photos of lips and cigarette butts. Additionally, | ||
only a small part of the lips touches the cigarette, | ||
only one side of a cigarette butt is visible, and it needs | ||
several uploaded photos of FB users to get a high | ||
fidelity lip model. To get a grip on the orthogonal | ||
curvatures and distortion we throw in the anisotropic | ||
surface mesh generator Jane Tournois works on, and | ||
we implemented the Lipschitz distance estimator to | ||
get the confidence value for the lip-cigarette-butt match. | ||
</p> | ||
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<p> | ||
FB opted for CGAL, as the exact computing paradigm | ||
helps to avoid false negatives (FB has to avoid accusing | ||
people who not even smoke). The floating point filters | ||
are key to not only being exact but also fast, as there | ||
are millions of smokers who have to be identified. | ||
Obviously, FB combines that with yellow-finger detection, | ||
the timeline information they have ("Hey, I am in Venice"), | ||
and whatever other data available. | ||
</p> | ||
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<p> | ||
As I wrote in the beginning, biometry is not evil as | ||
such, and improving society seems a more moral goal | ||
to us than target advertising. Similar applications | ||
we have in mind, are the detection of counterfeit Dolce | ||
and Gabana glasses, Lacoste T-shirts, and Louis Vuitton | ||
handbags. FB Singapore pointed out that identifying | ||
chewing gums on the sidewalk would interest them, but | ||
it is not clear yet how to adapt the Lipschitz distance | ||
estimator. | ||
</p> | ||
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<p> | ||
It was a mistake not to have discussed this at the last | ||
CGAL developer meeting or openly in the forums, but I | ||
had not expected such strong reactions when some of you | ||
heard from Jane that we work on "some biometry stuff". | ||
</p> | ||
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<p> | ||
best regards, | ||
</p> | ||
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<p> | ||
andreas | ||
<br>-- | ||
<br>Andreas Fabri, PhD | ||
<br>Chief Officer, GeometryFactory | ||
<br>Editor, The CGAL Project | ||
</p> |