RST Invariant Watermarking Scheme Using Genetic Algorithm and DWT-SVD

摘要

In recent research, geometric attack is one of the most challenging problems in digital watermark. Such attacks are very simple to defeat most of the existing digital watermark algorithms without destroying watermark itself. In this paper, a point matching measure is adopted for estimating the geometric transformation parameters. First, the affinc invariant points of the original and probe image are computed. Then, the best embedded coefficients are found via GA in which the fitness function is defined as the minimal change of the significant region after the watermarking embedding. Finally, the watermark embedding and extraction were implemented in digital wavelet transform (DWT) domain. The propose scheme actualizes blind extraction since not requiring the original image information. The watermark is embedded adaptively according to image texture. This method has been proved its robustness to various attacks through experiments, and it can recover the watermarking image when the watermarking is aggressed.