Improved affine resistant watermarking by using robust templates

This paper proposes an improved affine resistant watermarking over the template matching-based watermarking method. A one-way hash function is utilized to generate the highly secure embedding positions in the mid-frequencies against position attacks. A spread spectrum watermark is embedded into these positions in the frequency domain based on the local perceptual capability. Two structural template lines are then added in the polar coordinate system for detecting any combination of the geometrical distortions. The watermark is detected based on the correlation between the recovered and embedded watermarks. The experimental results demonstrate the robustness of the method against some common image processing operations such as JPEG compression, enhancement, and any combination of the geometrical distortions.