Abstract: A novel digital watermark algorithm based on wavelet transform and neural network was proposed. Firstly,the original image was divided into some small blocks (8 X 8 pixels). The sub-image consists of some small blocks that are selected throuth logistic map. Two sub-bands LHl and HLl were generated by acting DWT on the sub-image. Secondly,the watermark was embedded into the sub-band's wavelet coefficients. The watermarked sub-image was reconstructed using CWT. Finally, we put every small block (8 X 8 pixels) of the watermarked sub-image into the initial position of the original image. Thus,we got the watermarked image. Experiments show that the watermark embedded by this scheme has good robustness,imperceptibility and security.

Key words: Watermark, Neural network, Wavelet transform, Chaos