Unit Progress
0% Complete

Computer Vision

Try these apps to see what they do.

  • Seeing-AI: https://www.microsoft.com/en-us/ai/seeing-ai
  • Quickdraw: https://quickdraw.withgoogle.com/
  • Scrroobly: https://www.scroobly.com/

Facial Recognition

Faces are essential to our individual identifications. Facial recognition is what most of us have been relying on to visually identify others. Facial recognition in AI has grown beyond standard visual recognition in its ability to not only recognize objects but also identify the person and the real-time expressions of the face.



In recent years, facial recognition has been adopted widely in the smartphone market. Apple’s iPhone X release brought about the ability of ‘Face Unlock’ to every user. Its Face ID technology is the most secure and reliable in the market at the moment, as it can recognize a face even when a person’s appearance changes due to factors such as facial hair, makeup, scarves, hats, glasses, contact lenses, and sunglasses. Even with these variables, the facial recognition works, including in total darkness.

Security System

Facial Recognition could be used to track people through surveillance cameras. It could be used to pinpoint certain people’s location and track their activities, which is useful in criminal investigation. Actually, the US Federal Bureau of Investigation has set up a machine learning system to identify criminal suspects from images of their faces. The FBI currently has a database that includes half of US residents’ faces, which could enable them to identify a person with a security camera footage. Home security systems use similar technologies to detect faces of the people that enter homes.

Facial Recognition and Expressions in Your Smartphone

How does it work?

Computers use 2D and/or 3D analysis to recognize crucial points on the human faces. The points, with derived distances, lengths, widths, and angles, form patterns that computers can associate with an identity. Your smartphone sees these patterns and associates the patterns with the input names.

How Does Computer Vision Describe A Face?

Generally, a face has four components: two eyes, one nose, and one mouth. Your phone can see that

  • “Each eye is represented by three points, forming a triangle.
  • The nose is represented by two points, forming a line.
  • The mouth is represented by four points. These can form a quadrilateral (as in “surprised”), a triangle, a curved line, or a straight line.” 

As a result of this, “a facial expression is represented by 12 points, or 24 numbers, since each point has both an x and a y coordinate. There is a complex mathematical function that maps these numbers into expressions like “’happy’” or “’sad.’” Currently, only the most powerful facial recognition software can recognize numerous emotions.


For more information, see






Sample Homework

Sample Quiz