As manifold as applications for image coding are today,
as manifold are the different approaches and algorithms and
were the first hardware implementations and even systems
in the commercial field, such as private teleconferencing
systems [l], [2]. However, with the advances in VLSItechnology
it became possible to open more application
fields to a larger number of users and therefore the necessity
for standards arose, because exchange of compressed
video data on national and international bases is mandatory
[32]. From the beginning of the 1980’s on, standardization
activities started within CCITT, followed by CCIR and IS0
later on. The outcome of these activities are CCITT Recommendations
H. 120 and H.261, CCIR Recommendations
721 and 723, IS0 10918 (JPEG), and IS0 11172 (MPEG-
1). IS0 13818 (MPEG-2) has just been drafted and IS0
MPEG-4 is in its developing phase.
This international standardization allows for large scale
production of VLSI systems and devices, thus making
the products cheaper and therefore more affordable for a
wide field of applications. Most important, it allows for
international video data exchange via storage media (e.g.,
CD-ROM) or via communication networks (e.g., ISDN).
The purpose of this paper is to provide an overview of
today’s image and video coding algorithms and standards
and their role in video communications. The paper is
organized as follows: In Section I1 we provide an outline of
the chronological development of video coding standards
and specific target applications. Section I11 reviews the
principles of image and video compression and algorithms
relevant to the standards coding schemes. In Section IV
commonalties and differences among the diverse coding
algorithms are outlined. Furthermore the specific properties
of the standards related to their applications are presented.
In Section V we discuss the performance of the standards
and their success in the market place.