Robust gray-scale logo watermarking in wavelet domain

In this paper, a robust logo watermarking scheme based on image fusion is proposed. Unlike existing watermarking schemes, the used watermark is a gray scale logo instead of randomly generated Gaussian noise type watermark. The core idea of the proposed scheme is to decompose an image into frequency sub-bands using wavelet transform followed by the embedding in selected blocks of sub-bands obtained by ZIG-ZAG sequence. Block selection is done by taking variance of the blocks into consideration. The experimental results show better visual imperceptibility and resiliency of the proposed scheme against intentional or un-intentional variety of attacks and superiority is carried out by comparison made by us with the existing schemes.