A New DCT-Based Watermarking Method for Copyright Protection of Digital Audio

Digital watermarking plays an important role for protecting digital contents from unauthorized copying. This paper proposes a new audio watermarking method based on Discrete Cosine Transformation (DCT) for copyright protection. In our proposed watermarking method, the original audio is transformed into DCT domain. The absolute values of DCT coefficients are divided into an arbitrary number of segments and the energy of each segment is calculated. Watermarks are then embedded into the selected peaks of the highest energy segment. Watermarks are extracted by performing the inverse operation of watermark embedding process. Simulation results indicate that our proposed watermarking method is highly robust against various kinds of attacks such as noise addition, cropping, re-sampling, re-quantization, MP3 compression, and echo, and achieves similarity values ranging from 13 to 32. In addition, our proposed method shows SNR (signal-to-noise ratio) values ranging from 13 dB to 24 dB.