Color Image Zero-Watermarking Using Accurate Quaternion Generalized Orthogonal Fourier–Mellin Moments

In recent years, digital image zero-watermarking algorithm has made great progress. But there are still some problems. First, most algorithms only focus on robustness and ignore discrimination. Second, most methods have good robustness against conventional signal attacks but poor robustness against geometric attacks. Thirdly, most of the existing zero-watermarking algorithms only focus on gray-scale images, and there are relatively few researches on color images. In order to cope with these issues, this paper introduces a novel color image zero-watermarking scheme using accurate quaternion generalized orthogonal Fourier–Mellin moments (AQGOFMMs). In the first stage of the proposed method, accurate computation of generalized orthogonal Fourier–Mellin moments (GOFMMs) based on the polar pixel tiling scheme. In the next stage, the high-precision GOFMMs are extended to the accurate quaternion GOFMMs (AQGOFMMs). Finally, the immutable set of features is extracted to construct a zero-watermark. It is worth mentioning that, different from the traditional way of constructing watermark with the amplitude of moments, this algorithm uses the full 4-D features of AQGOFMMs to construct watermark. The experiment proved that proposed zero-watermarking scheme gives a good balance between discriminability and robustness. Furthermore, the proposed algorithm achieves better performance than the other existing zero-watermarking.