New Copyright Protection Scheme for Digital Images Based on Visual Cryptography

The paper proposes a robust and blind watermarking scheme based on visual cryptography for copyright protection of digital images. It shuffles the pixel locations of the binary watermark using Arnold cat map transform to realize the effect of encryption for better security and it divides the image into blocks of equal size. Two secret shares are generated from the watermark and the image based on visual cryptography by comparing the global mean value of the pixels in the image with the mean values of all pixels of randomly selected blocks. As documented in the experimental results, the proposed scheme is more robust in comparison with other visual cryptography-based watermarking schemes. It can resist several attacks such as JPEG compression, gamma correction, impulse noise, Gaussian noise, blurring, median filter, rotation, scaling, and sharpening attacks on different types of images. The computational time for generating secret shares and detection of the watermark is comparatively small.