Research On Robust Image Watermarking Algorithm Based On Continuous Orthogonal Moments

With the vigorous development of network technology and digital media,today's society has stepped into the information age,and a large number of digital products are stored and transmitted in cyberspace,so how to protect the storage and dissemination of digital resources has become an issue of widespread concern in society.Digital watermarking technology stands out among many security technologies and shows unique advantages in the issue of digital resource copyright protection.In recent years,robust image watermarking technology has made great progress,and the existing robust image watermarking algorithms have been able to resist conventional image processing attacks well,but how to resist geometric attacks and improve computational accuracy are still common challenges in the field of digital image watermarking research.In this paper,we conduct an in-depth study on the above mentioned difficult problems in robust image watermarking algorithms,and the main works are as follows.:(1)An exact calculation method of polar harmonic Fourier moments(PHFM)is proposed using Gaussian numerical integration(GNI).Then a new watermarking algorithm based on exact PHFM and chaotic mapping is proposed to resist geometric attacks.The exact PHFM proposed in this paper has better geometric invariance,which greatly improves the ability of the algorithm to resist geometric attacks;by using the Tent chaos system to dislocate the watermarked image,which in turn makes the algorithm more secure.The algorithm is verified to be effective against different types of attacks and also shows its excellent performance when compared with similar watermarking algorithms.(2)To improve the performance,the above scheme is improved by combining exact PHFM and logistic chaotic mapping to propose a zero watermarking algorithm for remote sensing images,and the zero watermarking technique can provide protection of pixel details in remote sensing images.In the algorithm,the PHFM of the original grayscale image is calculated by using the exact GNI,after which the PHFM magnitude with good performance is selected for the construction of the binary feature image.Finally,the encrypted logo image is dissimilar to the feature image,and the generated zero watermark image is registered and deposited in a third-party organization,and the watermark construction phase is completed.When verifying the copyright ownership,the zero watermark image and the image to be verified are taken out from the third-party institution for dissimilarity,and the differences between the extracted logo image and the original logo image are compared to check the real owner of the image.After experimental comparison,the proposed algorithm in this paper has good robustness against both conventional image processing attacks and geometric attacks.(3)A novel zero watermarking scheme is proposed for simultaneously protecting the copyright of two similar medical images.First,an Accurate polar complex exponential transform(APCET)is designed using the GNI method.Then,the Ternary accurate polar complex exponential transform(TAPCET)is constructed based on the ternary number theory and APCET.Finally,a robust zero watermarking algorithm for two similar medical images is proposed based on TAPCET and chaotic mapping,which can be used for copyright protection of two similar medical images at the same time.Simulation experiments show that the scheme can resist interference from various types of attacks and also has excellent performance compared with other similar zero-watermarking algorithms.