Patent ID: 7487356

Claim:
A digital watermark embedding method comprising the steps of: scrambling a digital watermark to be embedded in host data and thereby generating a plurality of candidate watermarks; embedding the respective candidate watermarks in the host data by means of embedding a watermark bit value in each element of a sample set of the host data, so as to generate a plurality of candidate watermarked host data, the sample set having a plurality of elements which are sampled from the host data; extracting a possible watermark from each of the plurality of the candidate watermarked host data in which each candidate watermark has been embedded, by means of extracting a possible watermark bit from each element of a sample set for each of said plurality of the candidate watermarked host data, the sample set having a plurality of elements which are sampled from each of the plurality of the candidate watermarked host data; evaluating robustness of the respective candidate watermarks by calculating a detection error rate of the extracted possible watermark against the each candidate watermark which has been actually embedded in the host data; and obtaining watermarked host data in which one of the candidate watermarks is embedded with a high level of robustness.