A new robust watermarking system in integer DCT domain

In this paper, a robust watermarking technique is proposed using integer discrete cosine transform, non-linear chaotic map and dynamic stochastic resonance (DSR). Firstly, the host image is transformed into integer DCT domain where the coefficients are partitioned into non-over-lapping blocks. A circulant matrix is then constructed from the selected blocks. Block selection is done using a non-linear chaotic map. This circulant matrix is used for embedding the watermark by computing the singular values. The extraction of the watermark is done by producing the dynamic stochastic resonance (DSR) phenomena and casting a verification step. This verification step essentially solves the false positive detection problem that arises in SVD based watermarking. The experimental results demonstrate that the proposed scheme is imperceptible and robust against a variety of intentional or unintentional attacks.