Fast Robust Template Matching for Affine Resistant Image Watermarks

Abstract

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 for the accurate and e cient recovery of the template in an image which has undergone a general a ne transformation. Furthermore we demonstrate how the template can be used as a tool for asserting the presence of a watermark. We also systematically evaluate the algorithm and present results which demonstrate the robustness of the method against some common image processing operations such as compression, rotation, scaling and aspect ratio changes.

Image Authentication Under Geometric Attacks Via Structure Matching

“…Note this distance is generalized 1 because for the case that only one of the αi's is equal to one (corresponding to mi ∈ M that is farthest away from the closest point in N) and rest are zero, (13) reduces to the directed Hausdorff distance in (12). Also, if each of the α i = 1 |M| then this reduces to an average Hausdorff distance proposed for pattern matching by Jain et al [25].…”

“…For this reason, significant attention has been devoted in recent years towards developing geometrically invariant watermarking schemes. This includes periodic insertion of the mark [9,10,11], template insertion [12], mark embedding in geometrically invariant domains [13,14], and content based watermarking schemes that extract image feature points [15,16,17,18].…”

A Robust Image Watermarking Method based on Contourlet Transform for Correcting Geometric Attacks

“…It is resistant to cropping attack. Embedding is done in a low-frequency band which is a central component of DFT [4]. Amplification is achieved through scaling of image and cyclic shift is achieved through rotation of the image.…”

Watermarking security: theory and practice

“…Fig. (8) shows the results, except for SCS 3 . Surprisingly, the rate of the noise estimation variance is in 1/N o 2 for DSSS, SSP and MRE.…”

“…Some key events in this quest are the use of spread spectrum [1], the invention of resynchronization schemes [2], [3], the discovery of side information channel [4], [5], and the formulation of the opponent actions as a game [6].…”