Description

Watermarking is a technique to protect the copyright of digital media such as image, text, music and movie. In this study, a robust watermarking scheme for multiple cover images and multiple owners is proposed. The proposed scheme makes use of the visual cryptography (VC) technique, transform domain technique, chaos technique, noise reduction technique and error correcting code technique where the VC technique provides the capability to protect the copyright of multiple cover images for multiple owners, and the rest of the techniques are applied to enhance the robustness of the scheme. Then, the approximation sub image of the original digital image in the Discrete Wavelet Transform (DWT) domain was decomposed into non-overlapping blocks and the blocks with best abundant texture information were selected according to the size of binary watermark. Finally, the multi-watermark embedding was carried out by modifying the fractional part values of these selected block pixels based on the proposed discrete operation rule.