Archive for December, 2013

It all started with my regular B.Tech. classes at Delhi Technological University. My work and interests keep me far from having a big social life. It turns out that even after two years, I don’t  know everyone in my class. Its not about being oblivious, I know few friends completely, while I recognize many by just their face.

One day while travelling, a boy came to me and initiated a conversation. He knew me well enough! A face recognition algorithm back in my brain instructed me that he is someone from my class. But my neuron could not retrieve any other information about him from my brain (not even his name). I thought he might feel bad if I ask his name, so during the entire conversation I had to pretend as if I knew him.

Post conversation, I simply started thinking about a scene from “Mission Impossible: Ghost Protocol”, where an agent’s face recognition system triggers a false positive alarm. Fascinated from this, i thought to work on a miniature face recognition system of my own which I could later include in something big (shhh!!….concealed…).

But why face recognition after all…? Why do researchers spend their time on this..?

To answer this question, let us work on how we identify someone. We see, observe, and interact with various people around us or far in our day to day life. Our brain is so smart to recognize each person differently. We identify each other with Names and/or appearance. We even recognize some with their voice. Certainly of all other ways, we use Name and Appearance the most to identify a person. And out of all things that come under appearance, face has the most impact. That is, of all appearance features, we commonly use face to identify a person.

I represent above pictorially as below:

1

Now to decide among Name and Face, let me ask you a simple question. My neighbor’s name is Sunny. So now considering that you know his name, can you identify him if he comes to you?
Certainly not!
But now if I tell you that my Neighbor looks like below, maybe you will be able to identify him next time you see him.

2
MY NEIGHBOR: SUNNY

We interact with the world around us through our senses. Our eyes are our windows into the world. The amount humans learn through their eyes should not be underestimated under any circumstances. Concretely, studies have show that even three day old babies are able to distinguish between known faces.

Getting a bit technical now! We are far from understanding how over brain actually decodes faces. But various human attempts have been made for face recognition to simulate something similar to our brain’s working. Now, OpenCV has few modules that can be used directly for this purpose.

Few useful links:

1) http://www.cognotics.com/opencv/servo_2007_series/part_2/index.html

2) http://docs.opencv.org/trunk/modules/contrib/doc/facerec/tutorial/facerec_video_recognition.html

3) http://docs.opencv.org/trunk/modules/contrib/doc/facerec/facerec_tutorial.html

Few Output Videos:

Face Detection:

Face Recognition

Face Recognition with prediction confidence