Speech Watermarking System
1. INTRODUCTION
With the rapid development of the speech, audio, image, and video compression methods, currently it is not a difficult task to spread digital multimedia over Internet. This makes the protections of digital intellectual property rights and content authentications have been a serious problem. Hence the technology of digital watermarking is received a large deal of attention. Generally, digital watermarking techniques are based on either spread spectrum methods or changing the least significant bits of selected coefficients of a certain signal transform. For speech watermarking, to ensure the embedded watermark is imperceptible, the audio marking phenomenon is considered together with these conventional techniques.
In addition, a speech watermarking system should be robust to various speech compression operations. The development of speech watermarking algorithms, therefore, involves a trade-off among speech fidelity, robustness, and watermark pattern embedding rate specifications. The speech watermarking techniques usually embed speech watermark in unnecessary parts of speech signal, or in human insensitivity auditory regions. Some of speech watermarking methods will change an interval to embed watermark. However, this kind of method has a drawback that is the unavoidably degradation of robustness.
In the other methods, the watermarks are embedded by the use of counterfeit human speech. It is unfortunate that such type of method also has the defect of weak robustness especially when the counterfeit human speech is destroyed. The distortion of the counterfeit human speech will also lead to the damage of the watermark
[pic] Fig 1.1: Block of General watermarking Scheme
Therefore, we can define watermarking systems as systems in which the hidden message is related to the host signal and non-watermarking systems in which the message is unrelated to the host signal. On the other hand,
With the rapid development of the speech, audio, image, and video compression methods, currently it is not a difficult task to spread digital multimedia over Internet. This makes the protections of digital intellectual property rights and content authentications have been a serious problem. Hence the technology of digital watermarking is received a large deal of attention. Generally, digital watermarking techniques are based on either spread spectrum methods or changing the least significant bits of selected coefficients of a certain signal transform. For speech watermarking, to ensure the embedded watermark is imperceptible, the audio marking phenomenon is considered together with these conventional techniques.
In addition, a speech watermarking system should be robust to various speech compression operations. The development of speech watermarking algorithms, therefore, involves a trade-off among speech fidelity, robustness, and watermark pattern embedding rate specifications. The speech watermarking techniques usually embed speech watermark in unnecessary parts of speech signal, or in human insensitivity auditory regions. Some of speech watermarking methods will change an interval to embed watermark. However, this kind of method has a drawback that is the unavoidably degradation of robustness.
In the other methods, the watermarks are embedded by the use of counterfeit human speech. It is unfortunate that such type of method also has the defect of weak robustness especially when the counterfeit human speech is destroyed. The distortion of the counterfeit human speech will also lead to the damage of the watermark
[pic] Fig 1.1: Block of General watermarking Scheme
Therefore, we can define watermarking systems as systems in which the hidden message is related to the host signal and non-watermarking systems in which the message is unrelated to the host signal. On the other hand,