Digital Watermarking of Audio Signals Using a Psychoacoustic Auditory Model and Spread Spectrum Theory
Ricardo Alexandrino Garcia · 1999
INTRODUCTION Every day the amount of recorded audio data and the possibilities to distribute it (i.e. by the Internet, CD recorders, etc) are growing. These factors can lead to an increase in the illicit recording, copying and distributing of audio material without respect to the copyright or intellectual property of the legal owners. Another concern is the tracking of audio material over broadcast media without the use of human listeners or complicated audio recognition devices. Audio watermarking techniques promise a solution to some of these problems. The concept of watermarking has been used for years in the fields of still and moving images. The basic idea of a watermark is to include a special "code" or information within the transmitted signal. This code should be transparent to the user (non-perceptible) and resistant against removal attacks of various types. In audio signals, the desired characteristics can be translated into: - Not perceptible (the audio informati