Introduction

We learned in the previous chapter how a camera captures a 3D scene by projecting light rays on a 2D sensor plane. The image produced is an accurate representation of what the scene looks like from a particular point of view, at the instant the image was captured. However, by its nature, the process of image formation eliminates all information concerning the depth of the represented scene elements. This chapter will teach how, under specific conditions, the 3D structure of the scene and the 3D pose of the cameras that captured it, can be recovered. We will see how a good understanding of projective geometry concepts allows us to devise methods that enable 3D reconstruction. We will therefore revisit the principle of image formation introduced in the previous chapter; in particular, we will now take into consideration that our image is composed of pixels.

Digital image formation

Let's now redraw a new version of the figure shown in Chapter 10 , Estimating Projective Relations...