Watermark algorithm based on chaotic encryption and contourlet domain

For the limitation of the wavelet transform in two-dimensional image, a block energy analysis contourlet domain digital watermarking algorithm is proposed. This algorithm is mainly from contourlet factor analysis of the energy preceding It firstly decompose the original image by contourlet, and choose the low-frequency sub-band decomposed image as a watermark embedding sub-band, and then makes the low-frequency sub-band for non-overlapping sub-blocks, at the same time calculates each sub-block coefficients respectively. In selecting a large block of energy to embed the encrypted watermark scrambling, and then through the inversing transform of contourlet, the watermarked image is received. These results prove that: the digital watermark embedding algorithm has a good visual effect, and it also has a good robustness of common image processing and geometric attacks.