  Watermarking is a technique for hiding of data in a medium coverage so that
its presence is not detectable by a human eye and is recoverable only by the
authorized recipient. Two of the most important features of watermarked image
are transparency and robustness which are largely related to the security of
watermarking algorithms. In this paper, an image watermarking scheme based on
BCH error correction code in Discrete Cosine Transformation (DCT) domain is
considered. Before embedding process, the watermark is encoded through BCH
coding. Then it is embedded into the Discrete Cosine Transformation (DCT)
coefficients of cover image. In order to decrease embedding complexity and
speed up the process of finding the best position to insert a watermark signal,
lookup table method is utilized. The key features of proposed method include
the reduction of time required in the process embedding of information,
security and ability to correct the error caused by variety of attacks and
destructions as well. Watermarked image robustness has been investigated
against different kinds attacks and the simulation results indicate that the
proposed algorithm outperforms the existing methods in terms of
imperceptibility, robustness and security.
