A Novel Audio Watermarking Algorithm for Copyright Protection Based on DCT Domain

Audio digital watermarking technology is the new means of audio reproduction, which can pre-implant the special data as a watermark to the audio signal which pass the information on behalf of the owner of identity and prove the user´s legitimacy. The novel technology of embedding image data into the audio signal and additive audio watermarking algorithm based on DCT domain is proposed. AC DCT coefficients play different influence in robust and inaudibility. First, we decompose the audio into no overlapping blocks (eight data per block). Then every block performs the DCT operation: watermark is embedded by modulating AC DCT coefficient. Every block is embedded one bit message. Experimental results demonstrate that the watermark is inaudible and this algorithm is robust to common operations of digital audio signal processing, such as low-pass filtering, smoothing, adding noise and so on. The extracted watermark image quality is showed by considering normalize correlation (NC) value with a suitable scaling parameter for embedding.