Oblivious image watermarking robust against scaling and geometric distortions

Abstract

Watermarking stays the main technical safeguard of electronic copyright. This paper presents the first public-domain obliviouswatermarking scheme for images which survives scaling and geometricdistortion attacks. Previous proposals are either proprietary, nonobliviousor require scaling or geometric distortion to be undone prior tomark recovery, which may not be practical in oblivious watermarking.The new scheme uses a tile-based embedding technique that allows markrecovery from a scaled or geometrically distorted watermarked image.Other properties of the scheme presented here are that it operates onthe spatial domain, supports multiple marking and does not requireprevious knowledge of the embedded copyright sequence. The latterproperty makes the proposed watermarking suitable for fingerprinting purposes.