In this paper, two blind digital audio watermarking technique are proposed according to the payload requirement which uses discrete cosine transform (DCT). In our method the watermark is embedded into the selected mid band coefficients of the DCT transformed audio. The selected coefficients are middle band DCT coefficients which are modified and quantized through the average energy of the selected sub frame for watermark embedding. The mid band frequency components are selected through experiments such that the effect of mp3 compression and the common signal processing operation has a minimum effect on these coefficients. Original audio will not be required for extraction of the watermark. To adapt to the mp3 attack a preprocessing step is embedded which did an mp3 conversion of the audio and convert again the audio to the original format prior to embedding. Also embedding is done on the selected blocks which satisfies minimum energy threshold. Experiments show that our scheme produces imperceptible audios and the watermarked audio is robust against common signal processing attacks.
['Tribhuwan Kumar Tewari', 'Vikas Saxena', 'J. P. Gupta']
A digital audio watermarking scheme using selective mid band DCT coefficients and energy threshold