An audio aggregate watermark based on Cloud model

This paper proposes an audio aggregate watermark algorithm based on cloud model. Break through the traditional watermarking which only works to a single audio, implement copyright protection for an audio aggregation. In this paper, firstly, all the audio works in the audio aggregation are performed wavelet transform respectively to get wavelet coefficients, the combination of a part of these coefficients are mapped into a considerable number of cloud drops, these cloud drops are served as zero-watermark. Secondly, employ reverse-cloud generator to calculate the three numerical characteristics Ex, En, He of cloud drops, utilize change rate of these characteristics to detect watermark and evaluate the similarity between original watermark and the extracted watermark. Experimental results show that the proposed algorithm can protect copyright of all audio in audio aggregation at the same time, and it is robust to attacks such as low-pass filtering, resampling, requantization, mp3 compression, cropping, etc.