A Frequency-Hopping Blind Watermarking Algorithm Based on Chaotic Sequence Locating

A frequency-hopping blind watermarking algorithm based on chaotic sequence locating is studied.The fractal dimension(FD) to describe the image's character was used to classify the image's blocks.Different frequency-hopping bands to embed watermark were chosen according to the very FD classifications.The exact position to embed watermarks in the chosen band were determined by the classification and the chaotic sequence,as the output of one-dimensional chaotic map.The classification and the initial values of the chaotic sequence were saved as the secret key.The watermark information was embedded by the relationship of the coefficients.With favorable transparency,simulation showed that the algorithm had a good robustness against noise,image processing,image compression,and malicious attacks.Adoption of chaotic sequences enhanced the security capability.