# Introduction

Since we are dealing with *amplitudes and phases*, it is
necessary two represent two values for each point in the pictures that
follow. I have adopted a colourful scheme for representing complex
numbers on the two-dimensional images. Amplitude is represented by
colour **saturation** and **brightness**, while phase is given
by **hue**. This is illustrated in the following figure:

The positive real (horizontal) axis to the right represents a phase of
0. Phase increases anti-clockwise, thus **0 degrees** is
*red*, **120 degrees** is *green*, and **240
degrees** is *blue*.

Note that positive real numbers are *red*, and negative real
numbers are *cyan*. *White* represents zero magnitude.

Some Fourier transforms.
Back to the index.