QIM-DM watermarking optimization based on inter-frequency contrast masking in the DCT domain

In this paper a watermarking scheme based on the human visual system (HVS) is presented. A quantization index modulation - dither modulation scheme is used in the discrete cosine transform domain for the embedding. The watermark quantization step is selected according to the inter-frequency masking effect computed by using a HVS-inspired objective image quality metric. Experimental results demonstrate the effectiveness and the robustness of the proposed solution.