In this paper a new digital watermarking technique is proposed based on discrete wavelet transform. In order to enhance the robustness of watermark

watermark was based on the content of the original image. Pesudorandom permutation

division and spectrum spread techniques were used to improve the robustness of watermark. Different from the traditional techniques

in our method

watermarks were embedded for two times

the holistic watermark was embedded first and then was divided watermark

and watermark here was embedded both into the low-frequency components of the wavelet transform of the image but also to the high-frequency components. The extraction process extracted both the holistic watermark and the divided watermark in turn. The watermark based on the content of the original image and the watermarks that given beforehand were compared in the same condition and the experimental results showed that this kind of watermark has a more robust than the techniques used the watermarks given beforehand. The experimental results also showed that the capacity of embedded watermark was related not only to the just noticeable difference of the human visual system but also to the characteristics of the watermark itself.