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Book Review
Techniques and Applications of Digital Watermarking and Content Protection by Michael Arnold, Martin Schmucker, and Stephen D. Wolthusen, Artech House, 2003, ISBN 1-58053-111-3.
Reviewed by Vladimir Botchev [vladimir.botchev@analog.com]
This book covers similar ground to Digital Watermarking, by Ingemar Cox et al. It has less theoretical emphasis, is shorter overall, and unfortunately doesn’t provide any links to software written or recommended by the authors (the Cox book has a nice educational collection of C code). Nevertheless, this book is worth serious consideration given its style. Very precise, at places it reads like a recipe for algorithm implementation; and it offers specific material on topics that were somewhat diluted in the earlier book’s more generic approach. For example, the chapter on audio data watermarking is unique in its practical approach.
The book begins with an introduction that includes historical details, as is usual for such a relatively new field. Chapter Two presents an overview of watermarking, explains how steganography differs, and proceeds further to the basic principles and the methodologies of early days, the so-called first generation. Chapter Three explains why, in the authors’ view, watermarking should be used—and where. Chapter Four discusses methods for embedding watermarks on still images.
Next comes the above-mentioned—very practical—chapter on audio-data watermarking. Many principles are presented; especially interesting is echo hiding, which may have uses beyond pure copy protection. Chapter Six discusses methods for various other data streams, such as video, three-dimensional data (e.g., computer animation), geometrical (for example, geographic maps) and even music scores. Perhaps the most interesting chapter is Chapter Seven, where the reader can learn of the known methods of attack to unlock watermarked contents—and how to evaluate the quality of the watermarking.
Chapter 8 gives insight into some other current data-protection methods that; though not really related to watermarking, have a similar purpose. Examples include the ubiquitous method of copy-disabling for VHS by disturbing the recorder AGC with false sync pulses, as well as some of the early methods for scrambling TV pictures—for example, the well-known random line-delay used initially by the French Canal+ TV channel. Chapter Nine delves into digital rights-management issues, and discusses some popular schemes such as dongles (named after software developer Don Gaul). In the final chapter, appropriately named Conclusion, the authors summarize the methods, principles and quality issues presented at length in the body of the book. Although this volume lacks the theoretical depth of Cox’s book, it is recommended as a fast first introduction into this rapidly evolving area at the leading edge of signal processing and computer engineering.
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