The Research Of The Digital Image Watermarking Based On Zernike Moments

With the rapid development of multimedia and Internet techniques,the digital workssecurity becomes an important and challenging research topic.Digital watermarking techniqueis an effective method for digital copyright protection and becomes an important research areain the field of information hiding.Now most of watermarking schemes are robust to commonsignal processing,but they are difficult to resist the geometric attacks such as rotation,scaleand shearing.So how to resist to geometric attacks is still a challenge.This paper researches onanti-geometric attacks based on digital image.Main work include in The article:1. This paper takes the static digital image watermarking as research object,systematically studied the technology of digital watermarking. The frameworks andmethods of embedding, detection and watermark signal encoding were presented. Theoreticalanalyses of the Robustness and the channel capacity was presented. These are helpful fordevelopment efficient watermarking schemes.researched on the typical image watermarkingalgorithm,focuses on watermarking algorithms and principles,and analyzes its strengthsand weaknesses. as well as achieved the above watermarking algorithm.2. We mainly do researches on image watermarking schemes with the ability to resistgeometric attacks. The related techniques are first studied including the invariant momenttheory, image normalization. Then watermark synchronization schemes are presented basedon Fourier-Mellin watermarking algorithms,And analyzed the advantages and disadvantagesrespectively.3. Zernike moments consist of a set of orthogonal and complex number moments whichhave some properties:invariantation under rotation,less sensitivity to noise, Express theeffectiveness, efficiency and multilevel expressive calculation etc.this paper presents ageometrically robust blind watermarking algorithm based on Zernike moment:firstly computethe Zernike moments of the original image；then computed and normalized the Zernikemoments.secondly,select some low-level Zernike moments;finally,the watermark were embedinto the original image by quantizing the mangnitudes of the Zernike moments. Duringwatermark detection, the same parameters are used to apply odd-even quantization on the Zernike moments magnitudes of the distorted image, producing the extracted watermarksequence. Then the similarity between the original watermark and the extracted one iscomputed and used to judge the presence of the watermark.Experimental results show itsrobustness to rotation,scaling,cropping,as well as common attackes such as JPEGcompression,added noise and filtering.