The term “video compression” is now a common household name. The field of still
image and video compression has matured to the point that it is possible to watch
movies on a laptop computer. Such is the rapidity at which technology in various
fields has advanced and is advancing. However, this creates a need for some to obtain
at least a simple understanding behind all this. This book attempts to do just that, to
explain the theory behind still image and video compression methods in an easily
understandable manner. The readers are expected to have an introductory knowledge
in college-level mathematics and systems theory.
The properties of a still image are similar to those of a video, yet different. A still
image is a spatial distribution of light intensity, while a video consists of a sequence
of such still images. Thus, a video has an additional dimension—the temporal dimension.
These properties are exploited in several different ways to achieve data
compression. A particular image compression method depends on how the image
properties are manipulated.
Due to the availability of efficient, high-speed central processing units (CPUs),
many Internet-based applications offer software solutions to displaying video in real
time. However, decompressing and displaying high-resolution video in real time,
such as high-definition television (HDTV), requires special hardware processors.
Several such real-time video processors are currently available off the shelf. One
can appreciate the availability of a variety of platforms that can decompress and display
video in real time from the data received from a single source. This is possible
because of the existence of video compression standards such as Moving Picture
Experts Group (MPEG).
This book first describes the methodologies behind still image and video compression
in a manner that is easy to comprehend and then describes the most popular
standards such as Joint Photographic Experts Group (JPEG), MPEG, and advanced
video coding. In explaining the basics of image compression, care has been taken
to keep the mathematical derivations to a minimum so that students as well as practicing
professionals can follow the theme easily. It is very important to use simpler
mathematical notations so that the reader would not be lost in a maze. Therefore,
a sincere attempt has been made to enable the reader to easily follow the steps in
the book without losing sight of the goal. At the end of each chapter, problems are
offered so that the readers can extend their knowledge further by solving them.