Research On Digital Image Watermarking Technology

With the increasing popularity of Internet technology and the digitization of information media,more and more attention has been paid to the secure transmission and copyright protection of digital media.Digital image watermarking technique is a very effective method for the copyright protection and integrity authentication of digital media.However,when the general digital image watermarking technique is applied to printing,some difficult problems arise.In the printing process,there will be a process of digital screening.In this process,after the screening algorithm is processed,the ordinary digital image will be converted to a halftone image,which will cause serious damage to the watermark information hidden in the ordinary digital image.In order to solve this problem,a halftone watermark anti-counterfeiting technology emerged.This technology embeds watermark information through the phase modulation of the dots in the digital screening process,and extracts the watermark information through the principle of raster interference,which can play a better anti-counterfeit in the printing field.Effective,but there is a problem of obvious watermark traces.In response to this problem,this paper studies the anti-counterfeiting technology of halftone watermarks,and proposes an improved watermark embedding method,which optimizes the problem of traces during watermark embedding,and can obtain better anti-counterfeiting effects.On this basis,this paper also develops a watermark anticounterfeiting software system that applies the improved algorithm,which integrates watermark embedding and watermark extraction functions,which has good usability and universality.In summary,the main work and contributions completed in this article are as follows:1.Studying different digital screening algorithms,analyzing the principles of different digital screening algorithms,and summarizing the characteristics of the dots formed by each screening algorithm.2.The principle of moire generation is studied,and the optical watermark model based on the phase modulation method,which uses the moire phenomenon for watermark anticounterfeiting,is analyzed and verified by experiments.3.The problems existing in the optical watermark model based on the phase modulation method are analyzed,and a watermark embedding method based on edge dot pre-modulation is proposed.The problem of traces in the watermark embedding is optimized,and the experiment is designed to verify the effectiveness of the proposed improved method to weaken the traces of watermark embedding is presented.At the same time,multi-threading technology is used in the watermark embedding process to improve the efficiency of watermark embedding.4.Based on C++,a set of watermark anti-counterfeiting software system with complete functions was designed and developed,and a number of test samples were used to test experiments to verify the effectiveness of the software system's watermark embedding and extraction,as well as the universality of material images.The paper has completed a lot of experimental work,and the experimental results verify the effectiveness of the improved algorithm model proposed.At the same time,the functional test also shows that the implemented digital watermark software system has complete functions,high efficiency and reliability,can easily realize the embedding and detection of digital watermarks,and can be applied to digital watermark anti-counterfeiting in the printing field.