1. Introduction

We see the world in smooth shades of colour, each blending into the next. Our vision is analogue. Computers, though, can only interpret digital signals, where every value is either 1 or 0.

So how do we convert between the two?

There needs to be a way of representing an image as a set of binary numbers, so that it can be stored in a file or displayed on a screen.

In this section we will look in detail at the process.

We will also discuss what is meant by terms such as colour depth and resolution, and how these relate to the file size.