Understanding the human visual system

Before we jump into OpenCV functionalities, we need to understand why those functions were built in the first place. It's important to understand how the human visual system works so that you can develop the right algorithms. The goal of the Computer Vision algorithms is to understand the content of images and videos. Humans seem to do it effortlessly! So, how do we get machines to do it with the same accuracy?

Let's consider the following figure:

The human eye captures all the information that comes along such as color, shapes, brightness, and so on. In the preceding image, the human eye captures all the information about the two main objects and stores it in a certain way. Once we understand how our system works, we can take advantage of this to achieve what we want. For example, here are a few things we need to know:

To get an idea of our field of view, let's take a look at the top view of a human and the angles at which we see various things:

Our visual system is actually capable of a lot more things, but this should be good enough to get us started. You can explore further by reading up on Human Visual System Models on the internet.