Audio watermarking alogrithm using subband energy

This paper proposes a novel watermarking algorithm that protects digital copyrights and is robust to attacks. The Algorithm contains two features: finding target subband based on energy and wetting adaptive quantization step-size. These features improve the robustness and preserve high audio quality. Watermarks are embedded in the subband including the significant part of the signal such as a pitch. Generally, the subband containing the pitch has the biggest energy. In order to find this subband, wavelet packet transform is used to decompose the signal into subbands and their energy is calculated. The signal of the selected subbands is transformed in frequency domain using FFT. The watermarks are embedded using quantization index modulation (QIM) for higher values of samples than a certain threshold. Our decoder uses the blind detection using the Euclidean distance between the received signals and the signals using QIM for the received signals. The proposed method shows less than 5% bit error ratio (BER) in the audio watermark benchmarking.