Improved image copyright protection scheme exploiting visual cryptography in wavelet domain

The last few years have seen a massive increment in the use of the Internet as a channel for sharing and transmitting data, thus requiring the need for copyright protection schemes able to preserve the ownership of the data. The idea of embedding a watermark directly in the data is however unacceptable in various fields of application, due to the intrinsic degradation introduced by non reversible watermarking schemes. Hence some zero watermarking schemes have been developed. In this work we propose an optimization of a recent watermarking method based on visual cryptography, by improving results against most commont types of attacks and achieving a higher perceptual quality of the extracted mark. © 2013 SPIE-ISandT.