The Research Of Audio Digital Watermark Technology Based On The Discrete Cosine Transforms

Audio digital watermarking technology is a kind of information hidden technology, which hidesthe secret message into the audio signal. It is used for the audio signal’s copyright protection orsecret communication without affect the audio quality of the audio signal. The main research objectof this paper is the discrete cosine transform domain audio digital watermarking algorithm. Themain work includes:First, this paper introduces the meaning of audio digital watermarking technology and its basiccharacteristics and common application areas; describes some common audio digital watermarkingalgorithms; describes the basic characteristics of the sound signals and researches human auditorycharacteristics, researches the discrete cosine transform theory and its application in audio digitalwatermarking algorithm.Second, the traditional algorithm has a defect that the watermark is only embedded into theaudio signal sequence in order, so this paper proposes a energy algorithm based on energy selection.The algorithm could adaptive search for the optimum watermark embedding point based on theaudio signal sequence time domain segment energy, and then embed the watermark by usingdiscrete cosine transform. The experimental simulation results illustrates the energy algorithm hasbetter robustness than traditional algorithm and doesn’t undermine the transparency.Third, the energy algorithm has two defects would reduce algorithm’s robustness: spatialcorrelation between the watermark image pixel and the watermark information maybe embeddedinto the point where its segment energy was weak, the energy improved algorithm is purposed inthis chapter. The Arnold transform is used to remove the spatial correlation. The average energythreshold of the audio signal segment is counted. The embedding coefficient is increased whensegment energy is smaller than the average energy threshold. The quality of the audio signal isreduced a small amount in order to improve the robustness of the algorithm.Fourth, summarizes this paper’s research work, investigates the research problem and looksinto the further research.