Introduction

In this chapter, we present the process for creating a digital image that can be displayed on a screen and manipulated by computers. A discussion about the eye anatomy is also given since it is essential to make devices able to reproduce the human vision.

A digital image is a visual representation of a numerical array that meassures a physical phenomenon. Consequently, a digital image can be seen as an array of numbers, on which mathematical operations can be performed. The array is not limited to two dimensions: it can have many dimensions depending of the type of image acquisition. Acquisition devices are never perfect and introduce various modifications to the image, such as subsampling, quantization, noise, etc. Then we see how to display an image (remember: an array of number) into a visual representation, especially the relationship between the numbers and colors. Finally, we introduce some very simple processings with arithmetic operations.