Geometrically Robust Digital Image Watermarking Based On Chebyshev-Fourier Moments

Digital information age, so that the transmission of multimedia information, circulation becomes very convenient, but the subsequent acts of infringement and piracy has become increasingly rampant.Digital watermarking technology works by adding the number is not easy to detect but differentiate between the secret information can be determined to achieve the purpose of copyright protection, the solution to the problem of multimedia information security complement method. 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 leida Li use of Lee and pseudo Zernike moment magnitude Zernike moments has rotational invariance, namely the design of a watermarking algorithm against geometric attacks, but when embedded watermark image is small, we can not extract the watermark image using Zernike moments. such as jiali Dong use of Jacobi - Fourier moments in the polar coordinate system extract the watermarking, and guorui Yin using circular harmonic - Fourier moments in the polar coordinate system extract the watermarking, though have achieved good results, but need the image in the two coordinate Inter-conversion, 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 Chebyshev - 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) Application of Chebyshev - Fourier moment of definition and theory, respectively, in polar coordinate and the Cartesian coordinate system is calculated and the reconstructed image. Experimental results show that, in the Cartesian coordinate system of the reconstructed image is not only high accuracy, and speed.(3) Application of Chebyshev - 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.