A Robust Chaos-Based Watermarking for Copyright Protection

In this paper, a novel technique for embedding watermarks into a host image on the frequency domain is proposed. Due to good randomness and easy reproducibility of chaos, the watermark is permuted by the chaotic sequence, then a number of reference points are selected in the low frequency bands of the DCT domain based on the chaotic sequences. Moreover, the watermark is self-extractable and the algorithm is simple. Experimental results show that the algorithm proposed in the paper is effective and robust to common signal processing operations and some geometric distortions,such as cropping.Especially,it receives high robustness under JPEG lossy compression and signal enhancement operations, such as sharpening.