Digital Image Watermarking with Double Encryption

A new kind of watermark-inserting and detecting algorithm based on stationary wavelet transform was proposed. Firstly the digitalwatermarking was transformed randomly (Arnold transformation), then encrypted by logistic. The encrypted watermarking was transformed to one-dimensional row vector, and the pixel value was sorted. The coefficient of one-dimensional of primitive image of stationary wavelet transformation was sorted too, then inserted sorted watermarking to the sorted low frequency, and turned it to two dimension data. Then the image is reconstructed with coefficients of high-frequency.

The process ofwatermarking inserted is the inversion of the process of watermarkingembedded. Finally withdraw the watermarking and obtained the primitivewatermarking after the anti-Arnold transformation. This algorithm chose the appropriate position to insert the watermarking. Experimental results indicate that this algorithm not only enables the watermarking to have the very good invisibility, but also makes the watermarking have very strong robustness to the general image attacks, such as noise, filter, rotation, compression and so on.