An Invisible Watermark Detection Technique without Using Original Images for Resolving Rightful Ownerships of Digital Images

Wenjun Zeng and Bede Liu

Digital watermarking has been recently proposed as the mean for copyright protection of multimedia data. Many of existing watermarking schemes focused on the robust means to mark an image invisibly without really addressing the $ends$ of invisible watermarking schemes. This paper first discusses some scenarios in which many current watermarking schemes fail to resolve the rightful ownership of an image. We then identify the key problems and discuss some crucial requirements for a $valid$ invisible w atermark detection. In particular, we argue that, for the particular application of resolving rightful ownership using invisible watermarks, it might be crucial to require that the original image not be $directly$ involved in the watermark detection process. A general framework for validly detecting the invisible watermarks is then proposed. Some requirements on the claimed signature are discussed to prevent the exi stence of any counterfeit scheme. The optimal detection strategy within the framework is derived. We show the effectiveness of this technique based on some visual-model-based watermark encoding schemes.