¿How does face detection works?

Adrian Felipe Vides Jimenez
3 min readJun 8, 2022
Demonstartion of a face filter
Example of face filter

You have probably seen one of those videos where people appear with glasses or beards without actually having one, or even with a completely different face, or maybe you are one in the videos. But have you wondered what is happening there? why can your face change so much out of the blue?

The answer to that is Face Detection or Facial Recognition:

Face detection — also called facial detection — is an artificial intelligence (AI) based computer technology used to find and identify human faces in digital images. Face detection technology can be applied to various fields — including security, biometrics, law enforcement, entertainment and personal safety — to provide surveillance and tracking of people in real time. — —Tech Target.

But how does it work?

You may be able to identify your face, friend's and relatives' when seeing them in a picture. Well, that is what Facial Recognition does; in a particular way. Being a lot of faces from all over the world on the Internet, this IA looks for certain characteristics when you are taking a picture or recording a video; distance between your eyes, distance from forehead to chin, etc, and then convert these characteristics into key points of your face

Example of key points
Example of key points

Then the filter you choose searches for those key points and uses them as a reference to place an object (e.g: glasses, beard, cap), transform your face (e.g: bigger eyes, dye your hair, frog face), remove background, etc.

But of course taking pictures is not their only use. A lot of companies and organizations are using this technology, as:

  • U.S. government at airports. Facial recognition systems can monitor people coming and going in airports. The Department of Homeland Security has used the technology to identify people who have overstayed their visas or may be under criminal investigation. Customs officials at Washington Dulles International Airport made their first arrest using facial recognition in August of 2018, catching an impostor trying to enter the country.
  • Mobile phone makers in products. Apple first used facial recognition to unlock its iPhone X, and has continued with the technology with the iPhone XS. Face ID authenticates — it makes sure you’re you when you access your phone. Apple says the chance of a random face unlocking your phone is about one in 1 million.
  • Social media companies on websites. Facebook uses an algorithm to spot faces when you upload a photo to its platform. The social media company asks if you want to tag people in your photos. If you say yes, it creates a link to their profiles. Facebook can recognize faces with 98 percent accuracy.

Now you have a better Idea of what Face detection is, how it works and some of its aplications



Adrian Felipe Vides Jimenez

I'm a Software Developer passionate by programming, videogames and music. Nowadays studying at Holberton School