A new robust, secure and high capacity watermarking schemes for image authentication and recovery via the Discrete Wavelet and Arnold's Tranform

In recent years digital watermarking and information hiding has become an important area of research as a result of the many copyright infringement or information tampering encountered during transmission or distribution of data over a network. This is due to the advancement in the speed of communication over the internet and the rapid growth of digital applications. In digital watermarking schemes, the watermark signal is either embedded in the spatial or the transform domain (such as Discrete Wavelet Transform, Discrete Fourier Transform or Discrete Cosine Transform) of the host or carrier image. In a conventional practice, transform domains are preferred for information embedding rather than a spatial domain, as spatial domains are more prone to distortions when subjected to various transforms and signal processing techniques.;In this thesis, we propose five new high security digital watermarking schemes based on the Discrete Wavelet Transform (DWT). The key features of these new algorithms are that they have a high data embedding capacity, high security, redundancy, and high tampering detection and information recovery. The effects, on these proposed schemes, of watermarked image tampering such as blurring, pixel tampering, noise, data compression, and DES encryption are shown here. We also analyze the extracted image recovery quality based on the amount of tampering sustained by the related watermarked image. This analysis is performed on all five proposed schemes and leads to a better understanding of the tradeoff between increasing the embedding capacity of a proposed scheme and the recovery quality of the resulting extracted hidden image (s).