Hughes/Computer Graphics, 3/E

Chapter 19. Enlarging and Shrinking Images

19.1. Introduction

In Chapters 17 and 18 you learned how images are used to store regular arrays of data, typically representing samples of some continuous function like “the light energy falling on this region of a synthetic camera’s image plane.” You also learned a lot of theoretical information about how you can understand such sampled representations of functions by examining their Fourier transforms. In this chapter, we apply this knowledge to the problems of adjusting image sizes (scaling images up and down, as shown in Figure 19.1, which are synonyms for “enlarging” and “shrinking”), and performing various operations such as edge detection.

Figure 19.1: Terminology for image scaling.

We assume ...