Image watermarking in DCT: an embedding strategy and algorithm

The strategy to deal with image watermarking embedment is explored. A new embedding strategy and an algorithm applying the strategy for watermarking in DCT domain is proposed. Based on a quantitative analysis on magnitude of DCT components, it is shown that more robustness can be achieved if watermarks are embedded in DC components since DC components have much larger perceptual capacity than any AC components. Applying this embedding strategy, an adaptive watermarking algorithm incorporating the feature of visual masking of human vision system is presented. Experimental results demonstrate that the embedding strategy is effective and the invisible watermarks generated are very robust.