Hey, I Know You! How A Computer Does It..

Mar 2, 2012 By Anita R
Anita R's picture

So you are walking by a digital billboard and suddenly an advertisement (ad) speaks to you, enticing you to the nearest store that has the favorite toy that all your friends are talking about and one you are craving for.

A moment later, as your older sibling passes by the same billboard, an ad for the latest fashion accessory is playing. Just her thing! Eerie...  Is that billboard a mind reader? If you think this is the stuff of science fiction, think again. This is the technology of the present, and is fast becoming a reality thanks to Facial Recognition.

Recently, a London bus stop has become quite a tourist attraction. Using this technology, an ad put up by the children’s charity Plan UK plays a full length ad only to women. When a man approaches the board, it simply displays a message of the charity’s website and no ad.


Let’s step back. Can you recall instances when you may have crossed a person on the road? A brief glance at the face is enough for you to recall that person in a flash at a different time and place. Each human face has approximately 80 nodal points. When we see a face, our brains act as a scanner and a few important characteristics get fixed in our minds and is stored away subconsciously. The brain reconstructs the face again by bringing back the stored data. Our amazing brain has the capacity to replay many of these images from the past and come up with near perfect matches.

What exactly are these nodal points or characteristics? It is the distance between the eyes, width of the nose, depth of the eye sockets, shape of the cheekbones, length of the jaw line, etc. Nature just isn't that precise. Within a basic pattern predetermined by our genes, physical parts in each of us form in slightly different ways from every other person who has ever lived. The combinations are simply numerous making it nearly impossible to find duplicates.

Now imagine automating it. The potential becomes enormous. Very swiftly, from just an image, nodal points can be quickly scanned and measured by a computer. Sophisticated software generates numerical codes or faceprints from this data and quickly matches them against large databases.

Opportunities and Drawback

Facial recognition works similar to fingerprinting, DNA matching, iris matching and palm printing. But unlike them, facial recognition has far more immense possibilities. Think about it. Photos do not need a person to touch a surface. Besides being 'contact-less', from a mere photo or digital image, sophisticated technology can actually classify people by their age, gender and ethnicity based just on facial characteristics. Think of the amazing possibilities in security, marketing and other areas.

But no technology is without its drawback. Many fear that a 'contact-less' technology like facial recognition is very intrusive, violates privacy and can be misused. Your picture can be taken without your consent! With security cameras everywhere post 9/11, the threat of profiling people using this technology is very real. 

Drawbacks apart, the sheer potential of the technology is spurring many innovative uses. Facebook for one is using the technology to automatically tag uploaded photos on their server. A lot of research and development is happening in this area. Brace yourself for some exciting times.

Critical Thinking: What are some of the ways you think facial recognition technology will evolve in future? Do you think it is a threat or an asset to us?


Courtesy: BBC, howstuffworks.com