Digital watermarking is widely used as an identification and control mechanism for rights management of digital multimedia content. In this paper, on the basis of a statistical model, we offer a comprehensive scheme for computing bit error ratios, false negative error ratios, and false positive error ratios in detecting multiple bits of information from watermarked and unmarked content. We apply this scheme to the analysis of an audio watermarking system we developed and compare predicted and observed error ratios to show its validity and effectiveness experimentally. In our proposed scheme, the detection of multiple bits is modeled as a statistical decision with threshold parameters in the multi-dimensional watermark space, in which each component of the location corresponds to the normalized sum of the detected watermark pattern for each bit. Error ratios are computed as a function of the threshold parameters from the probability distribution in the watermark space. Further, from experiments on our audio watermarking system, we discuss how the deterioration of watermarked content changes the distribution in the multi-dimensional watermark space.
By: Taiga Nakamura, Ryuki Tachibana, and Seiji Kobayashi
Published in: RT0367 in 2002
LIMITED DISTRIBUTION NOTICE:
This Research Report is available. This report has been submitted for publication outside of IBM and will probably be copyrighted if accepted for publication. It has been issued as a Research Report for early dissemination of its contents. In view of the transfer of copyright to the outside publisher, its distribution outside of IBM prior to publication should be limited to peer communications and specific requests. After outside publication, requests should be filled only by reprints or legally obtained copies of the article (e.g., payment of royalties). I have read and understand this notice and am a member of the scientific community outside or inside of IBM seeking a single copy only.
Questions about this service can be mailed to reports@us.ibm.com .