How Does A Computer Detect A Face?

Facial detection technology is still in it's infant stage but has improved dramatically over the last 16 years. It is still in most cases inaccurate, but can have numerous applications for for our daily lives! But how does a computer recognize our faces?

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Please note that in this post I will discuss a simple algorithm to understand how a computer can Identify an object as an face. There are more mathematics and gory algorithms to detect it, but I will keep it really simple for the average Joe reader

How a computer can detect an object as a face.

We humans are extremely good at detecting faces, in fact we are still better and faster than computers at this task. We have evolved to identify someone's state of emotion, where he looks and if something has a face! This is amazing because a face has a lot of variables and is ever changing. We can even identify a face that has grown old. One the biggest problems we faced with facial recognition is identifying an object as a face. We still have problems with that. We are at an advanced level with that. We can see faces in simple objects like a smiley or car like in the image down below.

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But how does a computer detect a face when it only sees bits of number like this:

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we are luckily good at seeing patterns, computers are also good at recognizing patterns. We have noticed patterns of how lights fall on a face. For example: The middle of one's nose is usually lighter than the sides like this:

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We can make a simple diagram to illustrate this light, dark effect of the nose:

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Image Credit: My own work

the same principle happens with the eyes:

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and the simplified diagram would look something like this:

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Image Credit: My own work

we can find similar patterns like the ones above all over the face. This patterns or similarities could be used to determine if an object has an face. There are three main steps to do this.

The first step is to change the original picture's colour into a gray scale version of the picture, like this:

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The second big step would be to divide the picture up in squires and let the program compare the dark and light ratio with that of the basic diagrams like this:

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The final part would be to mark this location of the face part, and render a square around the face like this:

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As mentioned above, our algorithms have improved significantly the last decade. This was a short and simple explanation of one of the oldest and widely used algorithm.

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Note : I was on a hiking trip this weekend. I will post photos of the trip soon. This is why I did not post anything this past week! This post is not of high quality but I am posting it to show I am alive! Better posts will come soon! Sorry for not notifying any of my followers about this trip. I want to thank everyone sticking to my account!

And as always

Thanks for reading!