文摘
The digital watermark is used for copyright protection, and the methods should have the robustness against various attacks such as JPEG compression, clipping, rotation, and scaling attacks. Based on the DCT-OFDM based watermarking method presented at IWIHC2014, we propose a method enhancing the performance in this paper. There are two ideas in the proposed method. One idea is to reduce the computational costs required for the synchronization recovery. The other idea is to encode watermark information by error correcting code and to decode it by maximum likelihood algorithm. As the result, our method has high robustness against the IHC evaluation criteria with less degradation of quality and less computational costs.