1.1 - Introduction to Digital Image and Video Processing

Abstract

This chapter provides an introduction to digital image and video processing. Digital images/videos are usually obtained by converting continuous signals into digital format, although “direct digital” systems are becoming more prevalent. The digital visual signals are viewed using diverse display media such as digital printers, computer monitors, and digital projection devices. An important aspect of digital imaging is the diversity of image types that arise, and which can be derived from nearly every type of radiation. Indeed, some of the most significant developments in medical imaging have arisen from new sensors that record image data from previously little-used sources of radiation, such as positron emission tomography (PET) and magnetic resonance imaging (MRI). The images are generally classified according to the way in which the interaction occurs. The chapter presents the different types of images that include reflection images, emission images, and absorption images. An important feature of digital images and video is that they are multidimensional signals, meaning that they are functions of more than a single variable. In the classic study of digital signal processing, the signals are usually one-dimensional functions of time. Images, however, are functions of two and perhaps three space dimensions, whereas digital video as a function includes a third (or fourth) time dimension as well.