A Multiple Watermarking Technique for Images based on Visual Cryptography

With the explosive growth of internet technology robust methods are being developed to protect the proprietary rights of the multimedia. In this paper, an invisible watermarking technique is proposed, to embed multiple binary watermarks into digital images based on the concept of Visual Cryptography (VC). Unlike traditional watermarking schemes, the watermarks are not embedded directly into the digital image. Instead, the proposed method constructs independent Master Shares for the authors according to the original image and the corresponding watermarks. When piracy happens, the authors can show their shares to reveal the watermarks. The proposed scheme embeds the watermarks without modifying the original host image. In addition, the size of the watermarks is not restricted to being smaller than that of the original host image. Experimental results prove that, the proposed watermarking technique is resilient to several common attacks.