Comments on Video Compression by Dr

Reviews and Comments on Video Compression

Comments by Dr. Michael Isnardi of Sarnoff Corporation

“Symes' well-written explanations and heavily illustrated examples of video compression make this important topic accessible to readers at all levels. His book is recommended reading for all new members of my group.”

Dr. Michael Isnardi
Head, Compression Systems
Sarnoff Corporation

Dr. Isnardi manages development and implementation of DTV compression algorithms for both the broadcast and consumer electronics industries. He gives DTV tutorials at major conferences, and has recently received a technical Emmy Award, an IEEE CES Third Millennium Medal and the David Sarnoff Award for his contributions.

Comments by Robert Saint John of Ligos Technology

"I bought your book Video Compression years ago at NAB, and it's considered one of the most valuable resources for new employees and our sales and marketing staff at Ligos Technologies. We're truly looking forward to your latest, Video Compression Demystified."

Robert W. Saint John
Director of Technical Marketing
Ligos Technology

From EBU Technical Review

There may never be a book that answers ALL the questions you were afraid to ask about video compression, but this one may come very close. Aimed at the video engineer working in the field, it explains simply and clearly both the current objectives and methods of video compression systems, and the systems of the future which will bombard the marketplace with this type of equipment.
After a general introduction to the subject and explanations of the basic techniques used for general data compression, the Author moves on to a more detailed examination of image compression and video compression. From his first-hand knowledge of the development firstly of JPEG and then MPEG, he is able to guide the reader through from the very origins of these two compression systems.

The book gives a background description of image structure, without which it is difficult to understand (i) how the redundancy of information can be exploited and (ii) the complexities of the many layers in MPEG. This leads the reader on to more detailed explanations of:

entropy coding, which sends the most common messages with the fewest bits;

differential coding, which exploits the predictability of the signal;

transforms, particularly the discrete cosine transform (DCT) which can separate the most vital information from the video signal and allow the least important information to be discarded if necessary;

and, finally, the choice of quantizing resolution by which bit-rate can be traded for noise.

Moving on from general techniques to particular systems, the Author looks in detail at the JPEG image compression which is used in almost all Non-Linear Editors currently on the market. Although it may now have been superseded by MPEG for the compression of true video, JPEG will probably be encountered for many more years in television production. Furthermore many of the techniques of JPEG, if not the parameter values, are used in the MPEG compression systems that have been developed. The effects of compression are well illustrated here and throughout the book by details taken from pictures before and after coding.

The major difference between JPEG and MPEG is that the latter exploits the temporal redundancy in video signals. How this is done and how successive images are analyzed to separate the movement from the random changes in the pictures is covered in a dedicated chapter. MPEG-1 was designed for the delivery of video at low bit-rates and it was only with the later MPEG-2 technology that systems that were suitable, firstly, for television delivery and, at a later stage, for television production were developed. Systems (in the plural) is the operative concept here because MPEG allows for many variants of its layers, and even the "profiles" which were chosen to cover the most likely uses are numbered in dozens.

MPEG-1 and MPEG-2 were designed to include the audio component of television, and the book explains how the coded video and audio signals are assembled into the complete "transport" datastream of a programme. The audio compression used in MPEG is covered but probably not in as much detail as an audio specialist would like.

The book concentrates on the JPEG and MPEG families of compression, which are open standards available from the ISO/IEC. However it does give due importance to (if not much detail on) other DCT systems which have been developed commercially, such as DV and SX. It also briefly describes the more esoteric proposals such as wavelet and fractal coding. Lastly, the Author covers the initial steps which are being taken in the process of exploiting MPEG for television delivery and production. But these developments are happening too quickly for the treatment to be anything other than a signposting towards the future.

If you are a broadcast television engineer and want an introduction to video compression, particularly MPEG, then this is the book for you. Even with the rapid developments taking place at the moment, it should also serve as a reference book on the basics of video compression for many years to come.

Video Compression
Peter D Symes
Hardbound volume of 322 pages
McGraw-Hill, 1998
Ref: ISBN 0-07-063344-4. Price:$55.00

Richard Chalmers

Reproduced by kind permission of the Editor of EBU Technical Review,
published by the European Broadcasting Union, Geneva, Switzerland

Click the image to buy this book at Amazon.com

Comments by Dr. Michael Isnardi of Sarnoff Corporation
“Symes' well-written explanations and heavily illustrated examples of video compression make this important topic accessible to readers at all levels. His book is recommended reading for all new members of my group.”
	Dr. Michael Isnardi Head, Compression Systems Sarnoff Corporation
Dr. Isnardi manages development and implementation of DTV compression algorithms for both the broadcast and consumer electronics industries. He gives DTV tutorials at major conferences, and has recently received a technical Emmy Award, an IEEE CES Third Millennium Medal and the David Sarnoff Award for his contributions.

Comments by Robert Saint John of Ligos Technology
"I bought your book Video Compression years ago at NAB, and it's considered one of the most valuable resources for new employees and our sales and marketing staff at Ligos Technologies. We're truly looking forward to your latest, Video Compression Demystified."
	Robert W. Saint John Director of Technical Marketing Ligos Technology

From EBU Technical Review
There may never be a book that answers ALL the questions you were afraid to ask about video compression, but this one may come very close. Aimed at the video engineer working in the field, it explains simply and clearly both the current objectives and methods of video compression systems, and the systems of the future which will bombard the marketplace with this type of equipment. After a general introduction to the subject and explanations of the basic techniques used for general data compression, the Author moves on to a more detailed examination of image compression and video compression. From his first-hand knowledge of the development firstly of JPEG and then MPEG, he is able to guide the reader through from the very origins of these two compression systems. The book gives a background description of image structure, without which it is difficult to understand (i) how the redundancy of information can be exploited and (ii) the complexities of the many layers in MPEG. This leads the reader on to more detailed explanations of: entropy coding, which sends the most common messages with the fewest bits; differential coding, which exploits the predictability of the signal; transforms, particularly the discrete cosine transform (DCT) which can separate the most vital information from the video signal and allow the least important information to be discarded if necessary; and, finally, the choice of quantizing resolution by which bit-rate can be traded for noise. Moving on from general techniques to particular systems, the Author looks in detail at the JPEG image compression which is used in almost all Non-Linear Editors currently on the market. Although it may now have been superseded by MPEG for the compression of true video, JPEG will probably be encountered for many more years in television production. Furthermore many of the techniques of JPEG, if not the parameter values, are used in the MPEG compression systems that have been developed. The effects of compression are well illustrated here and throughout the book by details taken from pictures before and after coding. The major difference between JPEG and MPEG is that the latter exploits the temporal redundancy in video signals. How this is done and how successive images are analyzed to separate the movement from the random changes in the pictures is covered in a dedicated chapter. MPEG-1 was designed for the delivery of video at low bit-rates and it was only with the later MPEG-2 technology that systems that were suitable, firstly, for television delivery and, at a later stage, for television production were developed. Systems (in the plural) is the operative concept here because MPEG allows for many variants of its layers, and even the "profiles" which were chosen to cover the most likely uses are numbered in dozens. MPEG-1 and MPEG-2 were designed to include the audio component of television, and the book explains how the coded video and audio signals are assembled into the complete "transport" datastream of a programme. The audio compression used in MPEG is covered but probably not in as much detail as an audio specialist would like. The book concentrates on the JPEG and MPEG families of compression, which are open standards available from the ISO/IEC. However it does give due importance to (if not much detail on) other DCT systems which have been developed commercially, such as DV and SX. It also briefly describes the more esoteric proposals such as wavelet and fractal coding. Lastly, the Author covers the initial steps which are being taken in the process of exploiting MPEG for television delivery and production. But these developments are happening too quickly for the treatment to be anything other than a signposting towards the future. If you are a broadcast television engineer and want an introduction to video compression, particularly MPEG, then this is the book for you. Even with the rapid developments taking place at the moment, it should also serve as a reference book on the basics of video compression for many years to come. Video Compression Peter D Symes Hardbound volume of 322 pages McGraw-Hill, 1998 Ref: ISBN 0-07-063344-4. Price:$55.00 Richard Chalmers
Reproduced by kind permission of the Editor of EBU Technical Review, published by the European Broadcasting Union, Geneva, Switzerland
*Click the image to buy this book at Amazon.com*