In this paper

a geometrically robust image watermarking algorithm based on significant region of normalized image is proposed. The geometrically invariant space is firstly constructed by using image normalization method. Then the significant region is obtained from the normalized image by utilizing the invariant centroid theory. The digital watermark is embedded into the significant region by quantizing the magnitudes of the selected wavelet coefficients. Experimental results show that the proposed scheme is not only invisible and robust against common signals processing

but also robust against the geometric distortion.