Multipurpose image watermarking in the domain of DWT based on SVD and ABC.

A novel multipurpose image watermarking algorithm is proposed in this work.Proposed scheme performs very efficiently in all the three purposes.Option to set user defined imperceptibility level.Auto calculation of optimization strengths to get maximum robustness.Even after multipurpose nature, the scheme can deal with complex attacks too. A multipurpose image watermarking scheme is proposed in the present work in order to provide tamper localization, self-recovery and ownership verification of the host image. For robust watermarking, gray scale watermark is utilized to provide generalization and wide applicability to proposed scheme. The host is first transformed into the wavelet domain using DWT (Discrete Wavelet Transform) and then singular values of transformed host are modified in accordance with the principal components of watermark. This insertion make the scheme free from false positive error as well as it provides a decent capacity too. After the insertion of robust watermark, the last two LSB (Least Significant Bit) of host are modified in such a way that it contains the scrambled and deterministic average representation of host itself along with the SVD (Singular Value Decomposition) based tamper localization information. The LSB insertion is used to locate the tampered region as well as to provide the self-recovery feature to the scheme. The robust insertion is also optimized with the help of ABC (Artificial Bee colony) in such a way that maximum robustness can be assured corresponding to user specific threshold of imperceptibility.