Geometrically Robust Digital Image Watermarking Based On Exponential-Fourier Moments

Digital watermarking technology, as an important application research, has developed in recent years, its academic feature rests with bestriding computer science, image information processing, multimedia technology, pattern recognitions, cryptography, digital communications, and other disciplines and fields. As an emerging technology in the digital age, digital watermarking technology has not yet formed an independent and integrated theoretical subject system, but its important practical role has caused great interest among many well-known universities, research institutions and companies at home and abroad. Therefore research and development of digital watermarking technology has important practical significance and commercial value.For digital image watermarking, often face attacks such as geometric attack, wave attack, noise attack and so on, which is difficult to defense geometric attacks. Now be able to resist geometric attacks, there are two main digital watermarking algorithm:the method based on image feature and the method based on moment invariants. The watermarking algorithm based on moment invariants is an effective method against geometrical attacks, such as Yin using Circular harmonic-Fourier moments in the polar coordinate system extract the watermarking, though have achieved good results, but calculation than larger, higher order of need. This gives the application of digital watermarking has brought many practical problems.In previous work, based on this paper, based on Exponential Fourier Moments digital watermarking algorithm robust to geometric attacks, mainly as follows:(1) Summary recent advances in the field of digital watermarking research and progress in a variety of digital watermarking algorithm is a more systematic study; (2) Calculated the definition of the expression on the Circular harmonic-Fourier moments, and than, used the Exponential-Fourier moments constructed the Circular harmonic-Fourier moments based on the relationships of the Index and the Trigonometric function. The Exponential-Fourier moments and The Circular harmonic-Fourier moments have the equivalent effect in mathematics, and the Exponential-Fourier moments have more simple forms. Reconstructed the original image based on the Exponential-Fourier moments. In the final, calculated the Exponential-Fourier moments in the Cartesian coordinate system;(3) Application of Exponential-Fourier Moments of nature, designed to resist geometric attacks asymmetric digital watermarking algorithm. Through theoretical analysis and experimental verification, the algorithm can extract a good watermark, through quantitative calculation to prove that a Cartesian coordinate system similar to the high watermark extraction.