A Tutorial for Audio Watermarking in the Cepstrum Domain

A Robust Audio Watermarking in Cepstrum Domain Composed of Sample's Relation Dependent Embedding and Computationally Simple Extraction Phase

“…The previous work we proposed in [34] shows that watermark bits embedded in audio signals considering the sample's relative state in a frame are robust against noise or attacks. Though embedding was done in the cepstrum domain but any domain could have been used for embedding watermarks considering the relation between the groups of samples.…”

“…As we observing [34] the cepstrum domain representation of audio signals exhibits more attackor noise-invariant quality during audio watermarking, here again the sub-frames are individually transformed to their corresponding cepstrum domain.…”

“…Unlike [34], the proposed watermarking extraction algorithm requires a bit more logical operation to extract a watermark which helps the algorithm to be more secured compared to [34]. The steps involved in the extraction process are described as follows.…”

“…In [34], we proposed a faster and efficient watermarking algorithm considering only the relation between the mean values of two consecutive sample groups. There, we calculated the mean values of each group of samples individually and then interchanged the mean values to embed watermarks.…”

“…But, the extraction algorithm used at the receiver was very easy for an intruder to literally disclose the embedding algorithm. Here, we propose a revised watermark embedding and extraction algorithm inspired from [34] but using four groups of samples instead of two and considering the relation between the 'differences of mean values' instead of 'mean values' only to embed watermarks. First, we divide each frame of a host audio signal into four equal-sized subframes and then individually convert each sub-frame into cepstrum representation.…”