Digital Watermarking and Steganography Fundamentals and Techniques 47574_C000.indd 1 11/13/07 4:04:25 PM 47574_C000.indd 2 11/13/07 4:04:25 PM Digital Watermarking and Steganography Fundamentals and Techniques Frank Y. Shih Boca Raton London New York CRC Press is an imprint of the Taylor & Francis Group, an informa business 47574_C000.indd 3 11/13/07 4:04:25 PM CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2008 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S. Government works Version Date: 20131104 International Standard Book Number-13: 978-1-4200-4758-5 (eBook - PDF) This book contains information obtained from authentic and highly regarded sources. Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the validity of all materials or the consequences of their use. 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Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com Dedication To my loving wife and children, to my parents who encouraged me through the years, and to those who helped me in the process of writing this book 47574_C000.indd 5 11/13/07 4:04:28 PM 47574_C000.indd 6 11/13/07 4:04:28 PM Table of Contents Chapter 1 Introduction ..........................................................................................1 1.1 Digital Watermarking .......................................................................................1 1.2 Digital Steganography .......................................................................................3 1.3 Differences between Watermarking and Steganography ..................................5 1.4 A Brief History..................................................................................................5 References ..................................................................................................................6 Appendix: Selected List of Books on Watermarking and Steganography ................7 Chapter 2 Classification in Digital Watermarking................................................9 2.1 Classification Based on Characteristics ............................................................9 2.1.1 Blind versus Nonblind ...........................................................................9 2.1.2 Perceptible versus Imperceptible .........................................................10 2.1.3 Private versus Public ...........................................................................10 2.1.4 Robust versus Fragile ..........................................................................10 2.1.5 Spatial Domain-Based versus Frequency Domain-Based ...................11 2.2 Classification Based on Applications ..............................................................11 2.2.1 Copyright Protection Watermarks .......................................................12 2.2.2 Data Authentication Watermarks ........................................................12 2.2.3 Fingerprint Watermarks ......................................................................12 2.2.4 Copy Control Watermarks ...................................................................13 2.2.5 Device Control Watermarks ................................................................13 References ................................................................................................................14 Chapter 3 Mathematical Preliminaries ...............................................................15 3.1 Least-Significant-Bit Substitution ...................................................................15 3.2 Discrete Fourier Transform (DFT) .................................................................15 3.3 Discrete Cosine Transform .............................................................................17 3.4 Discrete Wavelet Transform ............................................................................18 3.5 Random Sequence Generation ........................................................................21 3.6 The Chaotic Map .............................................................................................22 3.7 Error Correction Code ....................................................................................25 3.8 Set Partitioning in Hierarchical Tree ..............................................................28 References ................................................................................................................31 Chapter 4 Digital Watermarking Fundamentals .................................................33 4.1 Spatial-Domain Watermarking .......................................................................33 4.1.1 Substitution Watermarking in the Spatial Domain .............................33 4.1.2 Additive Watermarking in the Spatial Domain ...................................35 47574_C000.indd 7 11/13/07 4:04:29 PM 4.2 Frequency-Domain Watermarking .................................................................37 4.2.1 Substitution Watermarking in the Frequency Domain ........................37 4.2.2 Multiplicative Watermarking in the Frequency Domain ....................39 4.2.3 Watermarking Based on Vector Quantization.....................................41 4.2.4 The Rounding Error Problem ..............................................................41 4.3 The Fragile Watermark ...................................................................................44 4.3.1 The Block-Based Fragile Watermark ..................................................45 4.3.2 Weaknesses of the Block-Based Fragile Watermark ...........................46 4.3.3 The Hierarchical Block-Based Fragile Watermark .............................47 4.4 The Robust Watermark ...................................................................................48 4.4.1 The Redundant Embedding Approach ................................................49 4.4.2 The Spread Spectrum Approach .........................................................49 References ................................................................................................................49 Chapter 5 Watermarking Attacks and Tools .......................................................51 5.1 Image Processing Attacks ...............................................................................51 5.1.1 Attacks by Filtering .............................................................................51 5.1.2 Attack by Remodulation ......................................................................53 5.1.3 Attack by JPEG Coding Distortion .....................................................54 5.1.4 Attack by JPEG 2000 Compression ....................................................54 5.2 Geometric Transformation ..............................................................................55 5.2.1 Attack by Image Scaling .....................................................................55 5.2.2 Attack by Rotation ...............................................................................56 5.2.3 Attack by Image Clipping ...................................................................57 5.2.4 Attack by Linear Transformation ........................................................58 5.2.5 Attack by Bending ...............................................................................59 5.2.6 Attack by Warping...............................................................................59 5.2.7 Attack by Perspective Projection .........................................................59 5.2.8 Attack by Collage ................................................................................60 5.2.9 Attack by Template ..............................................................................60 5.3 Cryptographic Attack ......................................................................................61 5.4 Protocol Attacks ..............................................................................................61 5.5 Watermarking Tools ........................................................................................62 References ................................................................................................................62 Chapter 6 Combinational Digital Watermarking in the Spatial and Frequency Domains .....................................................................65 6.1 An Overview of Combinational Watermarking ..............................................66 6.2 Watermarking in the Spatial Domain .............................................................67 6.3 Watermarking in the Frequency Domain .......................................................68 6.4 Experimental Results ......................................................................................69 6.5 Further Encryption of Combinational Watermarking ....................................73 References ................................................................................................................75 47574_C000.indd 8 11/13/07 4:04:30 PM Chapter 7 Genetic Algorithm-Based Digital Watermarking ..............................77 7.1 Introduction to the Genetic Algorithm ...........................................................77 7.1.1 The Chromosome ................................................................................78 7.1.2 Basic Operations of the Genetic Algorithm ........................................80 7.1.2.1 Reproduction ........................................................................80 7.1.2.2 Crossover ..............................................................................80 7.1.2.3 Mutation ................................................................................80 7.1.3 The Fitness Function ...........................................................................81 7.2 The Concept of Genetic Algorithm-Based Watermarking .............................82 7.3 Genetic Algorithm-Based Rounding-Error Correction Watermarking ..........83 7.3.1 Definitions: Chromosome, Fitness Function, and Genetic Algorithm Operations ..........................................................................85 7.3.1.1 Chromosome .........................................................................85 7.3.1.2 Fitness Function ....................................................................86 7.3.1.3 Reproduction ........................................................................87 7.3.1.4 Crossover ..............................................................................87 7.3.1.5 Mutation ................................................................................87 7.3.2 The Genetic Algorithm-Based Rounding-Error Correction Algorithm ..........................................................................88 7.3.3 An Advanced Strategy for Initializing the First Population ...............90 7.4 An Application for Medical Image Watermarking .........................................93 7.4.1 An Overview of the Proposed Technique ...........................................94 7.4.1.1 The Signature Image ............................................................94 7.4.1.2 Textual Data ..........................................................................95 7.4.2 The Improved Scheme Based on Genetic Algorithms ........................98 7.4.3 Experimental Results.........................................................................101 References ..............................................................................................................103 Chapter 8 Adjusted-Purpose Digital Watermarking .........................................105 8.1 An Overview of Adjusted-Purpose Digital Watermarking ..........................105 8.2 The Morphological Approach for Extracting Pixel-Based Features ............107 8.3 The Strategies for Adjusting the Varying-Sized Transform Window and Quality Factor ..........................................................................110 8.4 Experimental Results ....................................................................................113 8.5 The Collecting Approach for Generating the VSTW ...................................115 References ..............................................................................................................119 Chapter 9 Robust High-Capacity Digital Watermarking..................................121 9.1 The Weakness of Current Robust Watermarking .........................................121 9.2 The Concept of Robust Watermarking .........................................................122 9.3 Enlargement of Significant Coefficients .......................................................122 9.3.1 Breaking the Local Spatial Similarity ..............................................122 9.3.2 The Block-Based Chaotic Map ..........................................................122 47574_C000.indd 9 11/13/07 4:04:31 PM