# The Geometry of Vision ## Lecture 4: The Extended Euclidean Plane

In order to develop Projective Geometry, we'll need to make some careful definitions. Let's start by taking a closer look at incidence.

There are certain basic axioms of incidence that a geometry of points and lines ougth to satisfy. Let's take a look at these now.

We're finally ready define points at infinity precisely!

Okay, we've defined the extended Euclidean plane...but is there a way to visualize it?

What new incidence relations do the points and lines of the extended Euclidean plane satisfy?