NEDELJKO C VE JIC
Department of Electrical and Information Engineering, Information Processing Laboratory, University of Oulu
ALGORITHMS FOR AUDIO WATERMARKING AND STEGANOGRAPHY
Academic Dissertation to be presented with the assent of the Faculty of Technology, University of Oulu, for public discussion in Kuusamonsali (Auditorium YB210), Linnanmaa, on June 29th, 2004, at 12 noon.
O U L U N Y L I O P I S TO, O U L U 2 0 0 4
Copyright © 2004 University of Oulu, 2004
Supervised by Professor Tapio Seppänen
Reviewed by Professor Aarne Mämmelä Professor Min Wu
ISBN 951-42-7383-4 (nid.) ISBN 951-42-7384-2 (PDF) http://herkules.oulu.fi/isbn9514273842/ ISSN 0355-3213 http://herkules.oulu.fi/issn03553213/
OULU UNIVERSITY PRESS OULU 2004
Cvejic, Nedeljko, Algorithms for audio watermarking and steganography Department of Electrical and Information Engineering, Information Processing Laboratory, University of Oulu, P.O.Box 4500, FIN-90014 University of Oulu, Finland 2004 Oulu, Finland
Broadband communication networks and multimedia data available in a digital format opened many challenges and opportunities for innovation. Versatile and simple-to-use software and decreasing prices of digital devices have made it possible for consumers from all around the world to create and exchange multimedia data. Broadband Internet connections and near error-free transmission of data facilitate people to distribute large multimedia files and make identical digital copies of them. A perfect reproduction in digital domain have promoted the protection of intellectual ownership and the prevention of unauthorized tampering of multimedia data to become an important technological and research issue. Digital watermarking has been proposed as a new, alternative method to enforce intellectual property rights and protect digital media from tampering. Digital watermarking is defined as imperceptible, robust and secure communication of data related to the host signal, which includes embedding into and extraction from the host signal. The main challenge in digital audio watermarking and steganography is that if the perceptual transparency parameter is fixed, the design of a watermark system cannot obtain high robustness and a high watermark data rate at the same time. In this thesis, we address three research problems on audio watermarking: First, what is the highest watermark bit rate obtainable, under the perceptual transparency constraint, and how to approach the limit? Second, how can the detection performance of a watermarking system be improved using algorithms based on communications models for that system? Third, how can overall robustness to attacks to a watermark system be increased using attack characterization at the embedding side? An approach that combined theoretical consideration and experimental validation, including digital signal processing, psychoacoustic modeling and communications theory, is used in developing algorithms for audio watermarking and steganography. The main results of this study are the development of novel audio watermarking algorithms, with the state-of-the-art performance and an acceptable increase in computational complexity. The algorithms' performance is validated in the presence of the standard watermarking attacks. The main technical solutions include algorithms for embedding high data rate watermarks into the host audio signal, using channel models derived from communications theory for watermark transmission and the detection and modeling of attacks using attack characterization procedure. The thesis also includes a thorough review of the state-of-the-art literature in the digital audio watermarking.
Keywords: audio watermarking, digital rights management, information hiding, steganography
To my family
The research related to this thesis has been carried out at the...