title: Robust template matching for affine resistant image watermarks.
abstract: Digital watermarks have been proposed as a method for discouraging illicit copying and distribution of copyrighted material. This paper describes a method for the secure and robust copyright protection of digital images. We present an approach for embedding a digital watermark into an image using the Fourier transform. To this watermark is added a template in the Fourier transform domain to render the method robust against general linear transformations. We detail a new algorithm based on polar maps for the accurate and efficient recovery of the template in an image which has undergone a general affine transformation. We also present results which demonstrate the robustness of the method against some common image processing operations such as compression, rotation, scaling, and aspect ratio changes.
authors.affiliation: Geneva Univ., Switzerland. shelby.pereira@cui.unige.ch
authors.forename: S
authors.initials: S
authors.lastname: Pereira
authors.forename: T
authors.initials: T
authors.lastname: Pun