Geometrical Attack Robust Spatial Digital Watermarking Based on Improved SIFT

Presents an effective against geometric attack robustness of digital watermarking algorithm based on improved SIFT(Scale Invariant Feature Transform). The proposal achieves watermark synchronization using improved Scale-Invariant Feature Transform; Some suitable feature points are selected to form circular patches of the carrier image. The circular patches are divided into sectors, and watermark is embedded into the sectors using spatial odds and even quantification. Watermark is extracted from an odd-even detector before detecting the rotated angle and the scale. Simulation results show that improved SIFT can reduce the matching dimension of feature point, improve the matching rate. And the proposed scheme achieves good image quality and it is able to resume a greater degree of geometric distortion.