Digital image copyright protection scheme based on visual cryptography and singular value decomposition

A digital image copyright protection scheme based on visual cryptography (VC) and singular value decomposition (SVD) techniques is proposed. In the proposed scheme, a master share is first constructed by applying SVD to a host image. Then, the master share is used together with a secret image to construct an ownership share, according to a two-out-of-two VC scheme. The secret image for ownership identification can be revealed by stacking the master share, and the ownership share. The proposed scheme embeds the secret image without modifying the host image. In addition, the hidden secret image can be extracted without resorting to the original host image and the aid of computers. Experimental results show that the proposed scheme, compared with existing schemes, achieves stronger robustness against several common attacks. (c) 2007 Society of Photo-Optical Instrumentation Engineers.