Researches On Digital Audio Watermarking

With the great development of the digital multimedia, the copyright protection technology to the digital multimedia contents such as photo, video and audio becomes more and more important. The traditional Encryption techniques can be used to protect digital multimedia contents during the transmission from the sender to the receiver. After the data has been decrypted at the receiver, however, the contents are no longer protected. As the replacement or supplement of encryption, the digital watermarking has been proposed. It protects digital multimedia contents by embedding special imperceptible messages such as copyright information or secret information into the original digital multimedia contents, and it may protect multimedia contents even after they are decrypted. Digital watermarking has been used in many ways such as broadcast monitoring, owner distinguishing, ownership proofing, transaction tracking, contents authentication, copy control and device control. Digital watermarking is a frontal subject in information security and has great importance in theory and practicality.In the paper, digital audio watermarking algorithms are studied. With analyzing some general algorithms, the paper introduces psychoacoustic model and puts forward several digital audio watermarking algorithms based on psychoacoustic model. The main work is introduced as follows:(1) Introduces the concept, the basic performance requirement and the application of watermarking; summarizes the classification of digital watermarking system; builds the digital watermarking model on the basis of communication model, and analyses the watermarking system from the point of view of communication.(2) Some work has been done on digital audio watermarking algorithms researching, particularly some general algorithms such as LSB, phase coding are introduced.(3 ) Researches digital audio watermarking algorithms based on psychoacoustic model.According to the simultaneous masking character of human audition system(HAS), combinedwith spread coding, two robust watermarking algorithms in different working domain are broughtforward; Based on the temporal masking character of HAS, combined with cepstrum peak detectingtheory, another robust watermarking algorithm-echo coding algorithm is brought forward. Thesetechniques and algorithms have increased ability of defending the anonymous and have decreased the error code ratio of the retrieved watermark remarkably.