CHAPTER 8. TECH BEHIND FACE RECOGNITION.
It is said that among 7.58 billion people on earthno two have the exact same face, except
identical twins but in the way you recognize the faceof your family members and close ones, in
the same way, face recognition works but with complexalgorithms and technology. Face
recognition has the capability to recognize anyone.So let’s see how this technology works.
In the early age of face recognition, it worked on2D image sensing just like you see your photo.
It was not super accurate as it lacked depth becausein a photo one cannot see the depth like
the size of nose, eyes, chin etc. And also 2d Imagesensing worked on the visible light spectrum
so it was not able to recognize a face in dark. Sothere was a great need to use 3d image
sensing and it was by IR rays. Phones having IR basedface recognition throw rays of harmless
IR rays on your face and it checks the time takenby rays to get reflect from your face and return
to the IR camera(ToF camera), the rays coming fromyour eyes will take less time then rays
coming from ears and in this way along with 2D sensingand IR camera the face recognition
started sensing in 3d and made it very accurate.
But this too worked in visible light so it could notrecognize a face in dark so there was a need
for new technology to be introduced to unlock thephone in the dark so thermal cameras were
introduced. Thermal Cameras too work on IR rays butthey don’t shoot IR rays on your face
rather they collect IR rays emitted from your faceHigh-temperature region emit a large amount
of IR rays whereas cold Object emits comparativelyless amount of IR rays so Thermal cameras
take multiple images depending on different rangeIR rays and by making a composite image it
recognize the face in dark too.