Cover dependent watermarking against ambiguity attacks

Abstract

Abstract Digital Image Watermarking using Singular Value Decomposition has a fundamental flaw of false watermark generation when Singular Values of the watermark are embedded into the cover. The proposed work embeds Principal Components of two watermarks instead, to overcome this flaw. These watermarks are embedded into horizontal and vertical sub-band coefficients of 3-level DWT of the cover respectively. Keys based on cover and watermarks are generated and used for cover and watermark verification during extraction. The proposed technique is secure because knowing the keys merely is not sufficient to extract the two watermarks. Correct combination of keys with the respective 3-level DWT coefficients is required. The work is proved to be robust against false watermark generation, false cover claim and general image processing attacks together with high imperceptibility. Colour images are used in HSV colour model and Value plane is used for embedding the watermark.