Naive background subtraction

Let's start the discussion from the beginning. What does a background subtraction process look like? Consider the following image:

The previous image represents the background scene. Now, let's introduce a new object into this scene:

As we can see, there is a new object in the scene. So, if we compute the difference between this image and our background model, you should be able to identify the location of the TV remote:

The overall process looks like this:

Does it work well?

There's a reason we call it the naive approach! It works under ideal conditions and, as we know, nothing is ideal in the real world. It does a reasonably good job of computing the shape of the given object...