Page 32 - Video Coding for Mobile Communications Efficiency, Complexity, and Resilience

Chapter 2

Video Coding: Fundamentals

2.1 Overview

This chapter gives a brief introduction to some fundamentals of video coding.
Many of the concepts introduced in this chapter will be referenced and used
in subsequent chapters. Section 2.2 gives some de nitions. Section 2.3 covers
analog video, whereas Section 2.4 concentrates on digital video. Section 2.5
introduces some of the basics of video coding. It also presents the perfor-
mance measures and the test sequences that will be used in this book. Section
2.6 reviews intraframe video coding methods, whereas Section 2.7 reviews
interframe coding methods.

2.2 What Is Video?

1
A still image is a spatial distribution of intensity that is constant with respect
to time [10]. Video, on the other hand, is a spatial intensity pattern that changes
with time. Another common term for video is image sequence, since video can
be represented by a time sequence of still-images.

2.3 Analog Video

2.3.1 Analog Video Signal
Video has traditionally been captured, stored, and transmitted in analog form.
The term analog video signal refers to a one-dimensional (1-D) electrical

1 Intensity is a measure over some interval of the electromagnetic spectrum of the /ow of power
that is radiated from, or incident on, a surface. It is usually measured in watts per square meter
[9].

9