What is the use of
facial recognition for humans, and companies? How efficient is it. And most importantly, does it put our freedom at
recognition tools are used by Internet giants, but also by smartphone
manufacturers, especially for unlocking phones, and for recognizing people in
democratization of facial recognition
The front camera
will first take a picture when you present your face and it will look for your
face in the image.
Figure 1: Face search and analysis via a smartphone
Once the position of the face is found, different
attributes are taken into account:
- Face shape
- Position and shape of the ears
- Distance between the eyes
- Position of the eyes
- Nose shape
- Position of the mouth
- Shape of the mouth/lips, etc.
Those values are used to create a pattern. Since the
objective of your phone is to verify that you are its owner, it will proceed to
an authentication. It will compare the pattern it has just calculated with the
one you gave it by registering your face the first time. Depending on the
security level, the phone will have a higher or lower recognition rate. As far
as identification is concerned, we try to determine who is the person we have
Figure 2: Face identification in open terrain
For example, if a child is wanted, his or her face
could be included in a database of wanted children. Each time a person passes
in front of the cameras of a station equipped with a facial recognition system,
their face is photographed. This is then analyzed to determine whether the face
photographed is that of a wanted person or not, and an extract of the photo
will be compared with those in the database of wanted children. If a pattern is
close enough to the face, an alert will be sent to an operator (there is a
match and therefore identification of an abducted child). However, the human
operator must remove any doubt and confirm that the recognition system has not
made a mistake.
Figure 3: Identification and second control by the
et deuxième contrôle par l’œil humain
Should we worry about being identified and tracked
around the world?
There are limits... and loopholes
Don't panic, your secret identity will not be revealed
so easily. This is not because you want to preserve your privacy, but because, contrary
to what movies or video games sell you, it is not that easy to recognize a face
in a free environment.
When you teach a system that a person's ears are 4 cm
long and 2.5 cm wide, it's with a frontal image taken at a specific distance.
If the person turns their head 30°, the ears no longer have the same surface
area. It is also important to control the light and the background where you
take the picture. If there is a bigger shadow at one place of the nose, you
distort the shape of the nose. But when you want to use a system to control a
"free" space, you don't control the light or the background. Nor do
we control the angle of the face at the time of acquisition and neither the distance at which people will be at the
time of the acquisition of the image. In short, many elements are not
controlled. And these can have an impact on the appearance of the person.
When the GAFAMs get involved
GAFAM -Google, Amazon, Facebook, Apple, Microsoft-,
the leading companies in the digital world, have developed proprietary
algorithms for facial recognition. We find Deepface (a combination of
deep-learning and face) at Facebook, Or Face Net for Google, which uses it on
These algorithms are based on various learning methods
to determine a "normalized" image of your face. To do this, it needs
several photos with a rigid expression, and without a pose (otherwise the
learning is wrong). The algorithms will extract information from the different
photos they are given. They will process them in a statistical way to know
better and better how to identify you.
As for any learning system, the more data they have in
input, the more they can adjust their accuracy. The pictures you put on the
internet or on social networks will be good input data. But don't worry, the
98%+ recognition scores of the latest algorithms must be balanced with the
constraints on photo types and their variability. These elements apply on a
smaller scale with fingerprint identification.
Technological evolution leads to societal evolution
Facial recognition is a powerful tool for increasing
the security of places and devices. Facial recognition tools combined with
artificial intelligence tools will lead to major upheavals in the evolution of
technology and our relationship to society, security and privacy. This
evolution generates new questions from a legislative and ethical point of view.
But facial recognition can also help people suffering
from a rare disease such as prosopagnosia, which is characterized by the
impossibility of recognizing a familiar face. Great developments are yet to
come in the field of personal assistance with various applications that,
fortunately, are not limited to security.
Inspired by the research of Dr. Paul Ekman, a pioneer
in the field of behavioral science who
inspired the character of the series Lie to me, we could theoretically (but still only
theoretically) read the lies and emotions on faces. But that is for a more